CoreWebView2 Class

Article
11/18/2024

WebView2 enables you to host web content using the latest Microsoft Edge browser and web technology.

Summary

Members	Description
BrowserProcessId	Gets the process ID of the browser process that hosts the WebView.
CanGoBack	`true` if the WebView is able to navigate to a previous page in the navigation history.
CanGoForward	`true` if the WebView is able to navigate to a next page in the navigation history.
ContainsFullScreenElement	Indicates if the WebView contains a fullscreen HTML element.
CookieManager	Gets the CoreWebView2CookieManager object associated with this CoreWebView2.
DefaultDownloadDialogCornerAlignment	The default download dialog corner alignment.
DefaultDownloadDialogMargin	The default download dialog margin relative to the WebView corner specified by CoreWebView2.DefaultDownloadDialogCornerAlignment.
DocumentTitle	Gets the title for the current top-level document.
Environment	Exposes the CoreWebView2Environment used to create this CoreWebView2.
FaviconUri	Get the Uri as a string of the current Favicon. This will be an empty string if the page does not have a Favicon.
FrameId	The unique identifier of the main frame. It's the same kind of ID as with the CoreWebView2Frame.FrameId and CoreWebView2FrameInfo.FrameId.
IsDefaultDownloadDialogOpen	True if the default download dialog is currently open.
IsDocumentPlayingAudio	Indicates whether any audio output from this CoreWebView2 is playing. `true` if audio is playing even if CoreWebView2.IsMuted is true.
IsMuted	Indicates whether all audio output from this CoreWebView2 is muted or not. Set to true will mute this CoreWebView2, and set to false will unmute this CoreWebView2. `true` if audio is muted.
IsSuspended	Whether WebView is suspended.
MemoryUsageTargetLevel	Desired CoreWebView2MemoryUsageTargetLevel of a WebView.
Profile	The associated CoreWebView2Profile object of CoreWebView2.
Settings	Gets the CoreWebView2Settings object contains various modifiable settings for the running WebView.
Source	Gets the URI of the current top level document.
StatusBarText	The current text of the statusbar as defined by Window.statusbar.
AddHostObjectToScript	Adds the provided host object to script running in the WebView with the specified name.
AddScriptToExecuteOnDocumentCreatedAsync	Adds the provided JavaScript to a list of scripts that should be run after the global object has been created, but before the HTML document has been parsed and before any other script included by the HTML document is run.
AddWebResourceRequestedFilter	This is an overload method that allows to subscribe to WebResourceRequested events received outside of main page.
AddWebResourceRequestedFilter
CallDevToolsProtocolMethodAsync	Runs an asynchronous DevToolsProtocol method.
CallDevToolsProtocolMethodForSessionAsync	Runs an asynchronous `DevToolsProtocol` method for a specific session of an attached target.
CapturePreviewAsync	Captures an image of what WebView is displaying.
ClearServerCertificateErrorActionsAsync	Clears all cached decisions to proceed with TLS certificate errors from the CoreWebView2.ServerCertificateErrorDetected event for all WebView2's sharing the same session.
ClearVirtualHostNameToFolderMapping	Clears a host name mapping for local folder that was added by CoreWebView2.SetVirtualHostNameToFolderMapping.
CloseDefaultDownloadDialog	Close the default download dialog.
ExecuteScriptAsync	Runs JavaScript code from the `javaScript` parameter in the current top-level document rendered in the WebView.
ExecuteScriptWithResultAsync	Runs JavaScript code from the `javaScript` parameter in the current top-level document rendered in the WebView, The result of the execution is returned asynchronously in the CoreWebView2ExecuteScriptResult object which has methods and properties to obtain the successful result of script execution as well as any unhandled JavaScript exceptions.
GetDevToolsProtocolEventReceiver	Gets a DevTools Protocol event receiver that allows you to subscribe to a DevToolsProtocol event.
GetFaviconAsync	Get the downloaded Favicon image for the current page and copy it to the image stream.
GoBack	Navigates the WebView to the previous page in the navigation history.
GoForward	Navigates the WebView to the next page in the navigation history.
Navigate	Causes a navigation of the top level document to the specified URI.
NavigateToString	Initiates a navigation to `htmlContent` as source HTML of a new document.
NavigateWithWebResourceRequest	Navigates using a constructed CoreWebView2WebResourceRequest object.
OpenDefaultDownloadDialog	Open the default download dialog.
OpenDevToolsWindow	Opens the DevTools window for the current document in the WebView.
OpenTaskManagerWindow	Opens the Browser Task Manager view as a new window in the foreground.
PostSharedBufferToScript	Share a shared buffer object with script of the main frame in the WebView.
PostWebMessageAsJson	Same as CoreWebView2.PostWebMessageAsJson, but also has support for posting DOM objects to page content.
PostWebMessageAsJson	Posts the specified `webMessageAsJson` to the top level document in this WebView.
PostWebMessageAsString	Posts a message that is a simple string rather than a JSON string representation of a JavaScript object.
PrintAsync	Print the current web page asynchronously to the specified printer with the provided settings.
PrintToPdfAsync	Print the current page to PDF asynchronously with the provided settings.
PrintToPdfStreamAsync	Provides the Pdf data of current web page asynchronously for the provided settings.
Reload	Reloads the current page.
RemoveHostObjectFromScript	Removes the host object specified by the name so that it is no longer accessible from JavaScript code in the WebView.
RemoveScriptToExecuteOnDocumentCreated	Removes the corresponding JavaScript added via CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync with the specified script ID.
RemoveWebResourceRequestedFilter	This is an overload method that allows to unsubscribe from WebResourceRequested events received outside of main page.
RemoveWebResourceRequestedFilter	Warning: This method and are deprecated.
Resume	Resumes the WebView so that it resumes activities on the web page.
SetVirtualHostNameToFolderMapping	Sets a mapping between a virtual host name and a folder path to make available to web sites via that host name.
ShowPrintUI	Opens the print dialog to print the current web page.
ShowSaveAsUIAsync	Async method to programmatically trigger a Save As action for the currently loaded document.
Stop	Stops all navigations and pending resource fetches.
TrySuspendAsync	An app may call this API to have the WebView2 consume less memory.
BasicAuthenticationRequested	BasicAuthenticationRequested event is raised when WebView encounters a Basic HTTP Authentication request as described in https://developer.mozilla.org/docs/Web/HTTP/Authentication, a Digest HTTP Authentication request as described in https://developer.mozilla.org/docs/Web/HTTP/Headers/Authorization#digest, an NTLM authentication or a Proxy Authentication request.
ClientCertificateRequested	ClientCertificateRequested is raised when WebView2 is making a request to an HTTP server that needs a client certificate for HTTP authentication. Read more about HTTP client certificates at RFC 8446 The Transport Layer Security (TLS) Protocol Version 1.3.
ContainsFullScreenElementChanged	ContainsFullScreenElementChanged is raised when the CoreWebView2.ContainsFullScreenElement property changes.
ContentLoading	ContentLoading is raised before any content is loaded, including scripts added with CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync. ContentLoading is not raised if a same page navigation occurs (such as through fragment navigations or `history.pushState` navigations).
ContextMenuRequested	ContextMenuRequested is raised when a context menu is requested by the user and the content inside WebView hasn't disabled context menus.
DOMContentLoaded	DOMContentLoaded is raised when the initial HTML document has been parsed.
DocumentTitleChanged	DocumentTitleChanged is raised when the CoreWebView2.DocumentTitle property changes and may be raised before or after the CoreWebView2.NavigationCompleted event.
DownloadStarting	DownloadStarting is raised when a download has begun, blocking the default download dialog, but not blocking the progress of the download.
FaviconChanged	Raised when the Favicon has changed. This can include when a new page is loaded and thus by default no icon is set or the icon is set for the page by DOM or JavaScript.
FrameCreated	FrameCreated is raised when a new iframe is created. Handle this event to get access to CoreWebView2Frame objects.
FrameNavigationCompleted	FrameNavigationCompleted is raised when a child frame has completely loaded (`body.onload` has been raised) or loading stopped with error.
FrameNavigationStarting	FrameNavigationStarting is raised when a child frame in the WebView requests permission to navigate to a different URI.
HistoryChanged	HistoryChanged is raised for changes to joint session history, which consists of top-level and manual frame navigations.
IsDefaultDownloadDialogOpenChanged	Raised when the CoreWebView2.IsDefaultDownloadDialogOpen property changes.
IsDocumentPlayingAudioChanged	IsDocumentPlayingAudioChanged is raised when document starts or stops playing audio.
IsMutedChanged	IsMutedChanged is raised when the mute state changes.
LaunchingExternalUriScheme	LaunchingExternalUriScheme is raised when a navigation request is made to a URI scheme that is registered with the OS.
NavigationCompleted	NavigationCompleted is raised when the WebView has completely loaded (`body.onload` has been raised) or loading stopped with error.
NavigationStarting	NavigationStarting is raised when the WebView main frame is requesting permission to navigate to a different URI.
NewWindowRequested	NewWindowRequested is raised when content inside the WebView requests to open a new window, such as through `window.open()`.
NotificationReceived	NotificationReceived is raised when a non-persistent notification is received.
PermissionRequested	PermissionRequested is raised when content in a WebView requests permission to access some privileged resources.
ProcessFailed	`ProcessFailed` is raised when any of the processes in the WebView2 Process Group encounters one of the following conditions:
SaveAsUIShowing	SaveAsUIShowing is raised when browser trys to open a save as dialog. It includes opening dialog manually from context menu or programmatically from CoreWebView2.ShowSaveAsUIAsync.
SaveFileSecurityCheckStarting	This event will be raised during system FileTypePolicy checking the dangerous file extension list.
ScreenCaptureStarting	ScreenCaptureStarting event is raised when the Screen Capture API is requested by the user using getDisplayMedia().
ScriptDialogOpening	ScriptDialogOpening is raised when a JavaScript dialog (`alert`, `confirm`, `prompt`, or `beforeunload`) displays for the WebView.
ServerCertificateErrorDetected	The ServerCertificateErrorDetected event is raised when the WebView2 cannot verify server's digital certificate while loading a web page.
SourceChanged	SourceChanged is raised when the CoreWebView2.Source property changes.
StatusBarTextChanged	StatusBarTextChanged event is raised when the text in the Window.statusbar changes. When the event is fired use the property CoreWebView2.StatusBarText to get the current statusbar text.
WebMessageReceived	WebMessageReceived is raised when the CoreWebView2Settings.IsWebMessageEnabled setting is set and the top-level document of the WebView runs `window.chrome.webview.postMessage` or `window.chrome.webview.postMessageWithAdditionalObjects`.
WebResourceRequested	WebResourceRequested is raised when the WebView is performing a URL request to a matching URL and resource context filter that was added with CoreWebView2.AddWebResourceRequestedFilter(string, CoreWebView2WebResourceContext, CoreWebView2WebResourceRequestSourceKinds).
WebResourceResponseReceived	WebResourceResponseReceived is raised when the WebView receives the response for a request for a web resource (any URI resolution performed by the WebView; such as HTTP/HTTPS, file and data requests from redirects, navigations, declarations in HTML, implicit Favicon lookups, and fetch API usage in the document).
WindowCloseRequested	WindowCloseRequested is raised when content inside the WebView requested to close the window, such as after `window.close()` is run.

Properties

BrowserProcessId

readonly uint32_t BrowserProcessId

Gets the process ID of the browser process that hosts the WebView.

CanGoBack

readonly bool CanGoBack

true if the WebView is able to navigate to a previous page in the navigation history. If CanGoBack changes value, the CoreWebView2.HistoryChanged event is raised.

CanGoForward

readonly bool CanGoForward

true if the WebView is able to navigate to a next page in the navigation history. If CanGoForward changes value, the CoreWebView2.HistoryChanged event is raised.

ContainsFullScreenElement

readonly bool ContainsFullScreenElement

Indicates if the WebView contains a fullscreen HTML element.

CookieManager

readonly CoreWebView2CookieManager CookieManager

Gets the CoreWebView2CookieManager object associated with this CoreWebView2.

DefaultDownloadDialogCornerAlignment

CoreWebView2DefaultDownloadDialogCornerAlignment DefaultDownloadDialogCornerAlignment

The default download dialog corner alignment. The dialog can be aligned to any of the WebView corners (see CoreWebView2DefaultDownloadDialogCornerAlignment). When the WebView or dialog changes size, the dialog keeps it position relative to the corner. The dialog may become partially or completely outside of the WebView bounds if the WebView is small enough. Set the margin from the corner with the CoreWebView2.DefaultDownloadDialogMargin property. The corner alignment and margin should be set during initialization to ensure that they are correctly applied when the layout is first computed, otherwise they will not take effect until the next time the WebView position or size is updated.

DefaultDownloadDialogMargin

Point DefaultDownloadDialogMargin

The default download dialog margin relative to the WebView corner specified by CoreWebView2.DefaultDownloadDialogCornerAlignment. The margin is a point that describes the vertical and horizontal distances between the chosen WebView corner and the default download dialog corner nearest to it. Positive values move the dialog towards the center of the WebView from the chosen WebView corner, and negative values move the dialog away from it. Use (0, 0) to align the dialog to the WebView corner with no margin. The corner alignment and margin should be set during initialization to ensure that they are correctly applied when the layout is first computed, otherwise they will not take effect until the next time the WebView position or size is updated.

DocumentTitle

readonly string DocumentTitle

Gets the title for the current top-level document. If the document has no explicit title or is otherwise empty, a default that may or may not match the URI of the document is used.

Environment

readonly CoreWebView2Environment Environment

Exposes the CoreWebView2Environment used to create this CoreWebView2.

FaviconUri

readonly string FaviconUri

Get the Uri as a string of the current Favicon. This will be an empty string if the page does not have a Favicon.

FrameId

readonly uint32_t FrameId

The unique identifier of the main frame. It's the same kind of ID as with the CoreWebView2Frame.FrameId and CoreWebView2FrameInfo.FrameId. FrameId may not be valid if CoreWebView2 has not done any navigation. It's safe to get this value during or after the first CoreWebView2.ContentLoading event. Otherwise, it could return the invalid frame Id 0.

IsDefaultDownloadDialogOpen

readonly bool IsDefaultDownloadDialogOpen

True if the default download dialog is currently open. The value of this property changes only when the default download dialog is explicitly opened or closed. Hiding the WebView implicitly hides the dialog, but does not change the value of this property.

IsDocumentPlayingAudio

readonly bool IsDocumentPlayingAudio

Indicates whether any audio output from this CoreWebView2 is playing. true if audio is playing even if CoreWebView2.IsMuted is true.

IsMuted

bool IsMuted

Indicates whether all audio output from this CoreWebView2 is muted or not. Set to true will mute this CoreWebView2, and set to false will unmute this CoreWebView2. true if audio is muted.

IsSuspended

readonly bool IsSuspended

Whether WebView is suspended. True when WebView is suspended, from the time when CoreWebView2.TrySuspendAsync has completed successfully until WebView is resumed.

MemoryUsageTargetLevel

CoreWebView2MemoryUsageTargetLevel MemoryUsageTargetLevel

Desired CoreWebView2MemoryUsageTargetLevel of a WebView. An app may set CoreWebView2.MemoryUsageTargetLevel to indicate desired memory consumption level of WebView. Scripts will not be impacted and continue to run. This is useful for inactive apps that still want to run scripts and/or keep network connections alive and therefore could not call CoreWebView2.TrySuspendAsync and CoreWebView2.Resume to reduce memory consumption. These apps can set memory usage target level to CoreWebView2MemoryUsageTargetLevel.Low when the app becomes inactive, and set back to CoreWebView2MemoryUsageTargetLevel.Normal when the app becomes active.

It is not necessary to set CoreWebView2Controller's IsVisible property to false when setting the property.

It is a best effort operation to change memory usage level, and the API will return before the operation completes.

Setting the level to CoreWebView2MemoryUsageTargetLevel.Low could potentially cause memory for some WebView browser processes to be swapped out to disk in some circumstances. It is a best effort to reduce memory usage as much as possible. If a script runs after its related memory has been swapped out, the memory will be swapped back in to ensure the script can still run, but performance might be impacted. Therefore, the app should set the level back to CoreWebView2MemoryUsageTargetLevel.Normal when the app becomes active again. Setting memory usage target level back to normal will not happen automatically.

Profile

readonly CoreWebView2Profile Profile

The associated CoreWebView2Profile object of CoreWebView2.

Settings

readonly CoreWebView2Settings Settings

Gets the CoreWebView2Settings object contains various modifiable settings for the running WebView.

Source

readonly string Source

Gets the URI of the current top level document. This value potentially changes as a part of the CoreWebView2.SourceChanged event raised for some cases such as navigating to a different site or fragment navigations. It remains the same for other types of navigations such as page refreshes or history.pushState with the same URL as the current page.

StatusBarText

readonly string StatusBarText

The current text of the statusbar as defined by Window.statusbar.

Methods

AddHostObjectToScript

void AddHostObjectToScript(string name, Object rawObject)

Adds the provided host object to script running in the WebView with the specified name. Host objects are exposed as host object proxies via window.chrome.webview.hostObjects.{name}. Host object proxies are promises and will resolve to an object representing the host object. Only the COM visible objects/properties/methods can be accessed from script.

JavaScript code in the WebView will be able to access appObject as following and then access attributes and methods of appObject.

Note that while simple types, IDispatch and array are supported, and IUnknown objects that also implement IDispatch are treated as IDispatch, generic IUnknown, VT_DECIMAL, or VT_RECORD variant is not supported. Remote JavaScript objects like callback functions are represented as an VT_DISPATCH VARIANT with the object implementing IDispatch. The JavaScript callback method may be invoked using DISPID_VALUE for the DISPID. Such callback method invocations will return immediately and will not wait for the JavaScript function to run and so will not provide the return value of the JavaScript function. Nested arrays are supported up to a depth of 3. Arrays of by reference types are not supported. VT_EMPTY and VT_NULL are mapped into JavaScript as null. In JavaScript null and undefined are mapped to VT_EMPTY.

Additionally, all host objects are exposed as window.chrome.webview.hostObjects.sync.{name}. Here the host objects are exposed as synchronous host object proxies. These are not promises and calls to functions or property access synchronously block running script waiting to communicate cross process for the host code to run. Accordingly this can result in reliability issues and it is recommended that you use the promise based asynchronous window.chrome.webview.hostObjects.{name} API described above.

Synchronous host object proxies and asynchronous host object proxies can both proxy the same host object. Remote changes made by one proxy will be reflected in any other proxy of that same host object whether the other proxies and synchronous or asynchronous.

While JavaScript is blocked on a synchronous call to native code, that native code is unable to call back to JavaScript. Attempts to do so will fail with HRESULT_FROM_WIN32(ERROR_POSSIBLE_DEADLOCK).

Host object proxies are JavaScript Proxy objects that intercept all property get, property set, and method invocations. Properties or methods that are a part of the Function or Object prototype are run locally. Additionally any property or method in the array chrome.webview.hostObjects.options.forceLocalProperties will also be run locally. This defaults to including optional methods that have meaning in JavaScript like toJSON and Symbol.toPrimitive. You can add more to this array as required.

There's a method chrome.webview.hostObjects.cleanupSome that will best effort garbage collect host object proxies.

The chrome.webview.hostObjects.options object provides the ability to change some functionality of host objects.

Options property	Details
`forceLocalProperties`	This is an array of host object property names that will be run locally, instead of being called on the native host object. This defaults to `then`, `toJSON`, `Symbol.toString`, and `Symbol.toPrimitive`. You can add other properties to specify that they should be run locally on the JavaScript host object proxy.
`log`	This is a callback that will be called with debug information. For example, you can set this to `console.log.bind(console)` to have it print debug information to the console to help when troubleshooting host object usage. By default this is null.
`shouldSerializeDates`	By default this is false, and JavaScript Date objects will be sent to host objects as a string using `JSON.stringify`. You can set this property to true to have Date objects properly serialize as a `VT_DATE` when sending to the native host object, and have `VT_DATE` properties and return values create a JavaScript Date object.
`defaultSyncProxy`	When calling a method on a synchronous proxy, the result should also be a synchronous proxy. But in some cases, the sync/async context is lost (for example, when providing to native code a reference to a function, and then calling that function in native code). In these cases, the proxy will be asynchronous, unless this property is set.
`forceAsyncMethodMatches`	This is an array of regular expressions. When calling a method on a synchronous proxy, the method call will be performed asynchronously if the method name matches a string or regular expression in this array. Setting this value to `Async` will make any method that ends with Async be an asynchronous method call. If an async method doesn't match here and isn't forced to be asynchronous, the method will be invoked synchronously, blocking execution of the calling JavaScript and then returning the resolution of the promise, rather than returning a promise.
`ignoreMemberNotFoundError`	By default, an exception is thrown when attempting to get the value of a proxy property that doesn't exist on the corresponding native class. Setting this property to `true` switches the behavior to match Chakra WinRT projection (and general JavaScript) behavior of returning `undefined` with no error.
`shouldPassTypedArraysAsArrays`	By default, typed arrays are passed to the host as `IDispatch`. To instead pass typed arrays to the host as `array`, set this to `true`.

Host object proxies additionally have the following methods:

Method name	Details
`applyHostFunction`, `getHostProperty`, `setHostProperty`	Perform a method invocation, property get, or property set on the host object. Use the methods to explicitly force a method or property to run remotely if a conflicting local method or property exists. For instance, `proxy.toString()` runs the local `toString` method on the proxy object. But proxy.applyHostFunction('toString') runs `toString` on the host proxied object instead.
`getLocalProperty`, `setLocalProperty`	Perform property get, or property set locally. Use the methods to force getting or setting a property on the host object proxy rather than on the host object it represents. For instance, `proxy.unknownProperty` gets the property named `unknownProperty` from the host proxied object. But proxy.getLocalProperty('unknownProperty') gets the value of the property `unknownProperty` on the proxy object.
`sync`	Asynchronous host object proxies expose a sync method which returns a promise for a synchronous host object proxy for the same host object. For example, `chrome.webview.hostObjects.sample.methodCall()` returns an asynchronous host object proxy. Use the `sync` method to obtain a synchronous host object proxy instead: `const syncProxy = await chrome.webview.hostObjects.sample.methodCall().sync()`.
`async`	Synchronous host object proxies expose an async method which blocks and returns an asynchronous host object proxy for the same host object. For example, `chrome.webview.hostObjects.sync.sample.methodCall()` returns a synchronous host object proxy. Running the `async` method on this blocks and then returns an asynchronous host object proxy for the same host object: `const asyncProxy = chrome.webview.hostObjects.sync.sample.methodCall().async()`.
`then`	Asynchronous host object proxies have a `then` method. Allows proxies to be awaitable. `then` returns a promise that resolves with a representation of the host object. If the proxy represents a JavaScript literal, a copy of that is returned locally. If the proxy represents a function, a non-awaitable proxy is returned. If the proxy represents a JavaScript object with a mix of literal properties and function properties, the a copy of the object is returned with some properties as host object proxies.
`cancelPromise`	This method attempts to cancel the fulfillment of a promised value. If the promise hasn't already been fulfilled and cancelation is supported, the promise will get rejected. `cancelPromise` supports cancelation of IAsyncOperation and IAsyncAction methods. If the promise is successfully canceled, then calling await on the promise will throw. For example, `chrome.webview.hostObjects.cancelPromise(promise); await promise;` will throw with "Promise Canceled". Once a promise has been canceled, a subsequent cancel on the same promise will throw an exception as well.

All other property and method invocations (other than the above Remote object proxy methods, forceLocalProperties list, and properties on Function and Object prototypes) are run remotely. Asynchronous host object proxies return a promise representing asynchronous completion of remotely invoking the method, or getting the property. The promise resolves after the remote operations complete and the promises resolve to the resulting value of the operation. Synchronous host object proxies work similarly but block JavaScript execution and wait for the remote operation to complete.

Setting a property on an asynchronous host object proxy works slightly differently. The set returns immediately and the return value is the value that will be set. This is a requirement of the JavaScript Proxy object. If you need to asynchronously wait for the property set to complete, use the setHostProperty method which returns a promise as described above. Synchronous object property set property synchronously blocks until the property is set.

Exposing host objects to script has security risk. Please follow best practices. To create a IDispatch implementing class in C# use the following attributes on each class you intend to expose.

// Bridge and BridgeAnotherClass are C# classes that implement IDispatch and works with AddHostObjectToScript.
[ClassInterface(ClassInterfaceType.AutoDual)]
[ComVisible(true)]
public class BridgeAnotherClass
{
    // Sample property.
    public string Prop { get; set; } = "Example";
}

[ClassInterface(ClassInterfaceType.AutoDual)]
[ComVisible(true)]
public class Bridge
{
    public string Func(string param)
    {
        return "Example: " + param;
    }

    public BridgeAnotherClass AnotherObject { get; set; } = new BridgeAnotherClass();

    // Sample indexed property.
    [System.Runtime.CompilerServices.IndexerName("Items")]
    public string this[int index]
    {
        get { return m_dictionary[index]; }
        set { m_dictionary[index] = value; }
    }
    private Dictionary&lt;int, string&gt; m_dictionary = new Dictionary&lt;int, string&gt;();
}

Then add instances of those classes via CoreWebView2.AddHostObjectToScript:

webView.CoreWebView2.AddHostObjectToScript("bridge", new Bridge());

And then in script you can call the methods, and access those properties of the objects added via CoreWebView2.AddHostObjectToScript. Note that CoreWebView2.AddHostObjectToScript only applies to the top-level document and not to frames. To add host objects to frames use CoreWebView2Frame.AddHostObjectToScript.

// Find added objects on the hostObjects property
const bridge = chrome.webview.hostObjects.bridge;

// Call a method and pass in a parameter.
// The result is another proxy promise so you must await to get the result.
console.log(await bridge.Func("testing..."));

// A property may be another object as long as its class also implements
// IDispatch.
// Getting a property also gets a proxy promise you must await.
const propValue = await bridge.AnotherObject.Prop;
console.log(propValue);

// Indexed properties
let index = 123;
bridge[index] = "test";
let result = await bridge[index];
console.log(result);

AddScriptToExecuteOnDocumentCreatedAsync

IAsyncOperation<string> AddScriptToExecuteOnDocumentCreatedAsync(string javaScript)

Adds the provided JavaScript to a list of scripts that should be run after the global object has been created, but before the HTML document has been parsed and before any other script included by the HTML document is run. The injected script will apply to all future top level document and child frame navigations until removed with CoreWebView2.RemoveScriptToExecuteOnDocumentCreated. This is applied asynchronously and you must wait for the returned IAsyncOperation to complete before you can be sure that the script is ready to execute on future navigations. If the method is run in CoreWebView2.NewWindowRequested handler, it should be called before the new window is set. For more details see CoreWebView2NewWindowRequestedEventArgs.NewWindow.

Note that if an HTML document has sandboxing of some kind via sandbox properties or the Content-Security-Policy HTTP header this will affect the script run here. So, for example, if the allow-modals keyword is not set then calls to the alert function will be ignored.

AddWebResourceRequestedFilter

void AddWebResourceRequestedFilter(string uri, CoreWebView2WebResourceContext resourceContext, CoreWebView2WebResourceRequestSourceKinds requestSourceKinds)

This is an overload method that allows to subscribe to WebResourceRequested events received outside of main page.

AddWebResourceRequestedFilter

void AddWebResourceRequestedFilter(string uri, CoreWebView2WebResourceContext ResourceContext)

CallDevToolsProtocolMethodAsync

IAsyncOperation<string> CallDevToolsProtocolMethodAsync(string methodName, string parametersAsJson)

Runs an asynchronous DevToolsProtocol method. For more information about available methods, navigate to DevTools Protocol Viewer. The returned task is completed when the method asynchronously completes and will return the method's return object as a JSON string. Note even though WebView2 dispatches the CDP messages in the order called, CDP method calls may be processed out of order. If you require CDP methods to run in a particular order, you should await for the previous method call.

If the method is to run in CoreWebView2.NewWindowRequested handler it should be called before the new window is set if the cdp messages should affect the initial navigation. If called after setting the NewWindow property, the cdp messages may or may not apply to the initial navigation and may only apply to the subsequent navigation. For more details CoreWebView2NewWindowRequestedEventArgs.NewWindow.

CallDevToolsProtocolMethodForSessionAsync

IAsyncOperation<string> CallDevToolsProtocolMethodForSessionAsync(string sessionId, string methodName, string parametersAsJson)

Runs an asynchronous DevToolsProtocol method for a specific session of an attached target. There could be multiple DevToolsProtocol targets in a WebView. Besides the top level page, iframes from different origin and web workers are also separate targets. Attaching to these targets allows interaction with them. When the DevToolsProtocol is attached to a target, the connection is identified by a sessionId.

To use this API, you must set the flatten parameter to true when calling Target.attachToTarget or Target.setAutoAttach DevToolsProtocol method. Using Target.setAutoAttach is recommended as that would allow you to attach to dedicated worker targets, which are not discoverable via other APIs like Target.getTargets. For more information about targets and sessions, navigate to Chrome DevTools Protocol - Target domain.

For more information about available methods, navigate to DevTools Protocol Viewer. The handler's Invoke method will be called when the method asynchronously completes. Invoke will be called with the method's return object as a JSON string.

CapturePreviewAsync

IAsyncAction CapturePreviewAsync(CoreWebView2CapturePreviewImageFormat imageFormat, IRandomAccessStream imageStream)

Captures an image of what WebView is displaying. When CapturePreviewAsync finishes writing to the stream, the Invoke method on the provided handler parameter is called. This method fails if called before the first CoreWebView2.ContentLoading event. For example if this is called in the CoreWebView2.NavigationStarting event for the first navigation it will fail. For subsequent navigations, the method may not fail, but will not capture an image of a given webpage until the CoreWebView2.ContentLoading event has been fired for it. Any call to this method prior to that will result in a capture of the page being navigated away from.

ClearServerCertificateErrorActionsAsync

IAsyncAction ClearServerCertificateErrorActionsAsync()

Clears all cached decisions to proceed with TLS certificate errors from the CoreWebView2.ServerCertificateErrorDetected event for all WebView2's sharing the same session.

ClearVirtualHostNameToFolderMapping

void ClearVirtualHostNameToFolderMapping(string hostName)

Clears a host name mapping for local folder that was added by CoreWebView2.SetVirtualHostNameToFolderMapping.

CloseDefaultDownloadDialog

void CloseDefaultDownloadDialog()

Close the default download dialog. Calling this method raises the CoreWebView2.IsDefaultDownloadDialogOpenChanged event if the dialog was open. No effect if the dialog is already closed.

ExecuteScriptAsync

IAsyncOperation<string> ExecuteScriptAsync(string javaScript)

Runs JavaScript code from the javaScript parameter in the current top-level document rendered in the WebView. If the result is undefined, contains a reference cycle, or otherwise is not able to be encoded into JSON, the JSON null value is returned as the "null" string.

A function that has no explicit return value returns undefined. If the script that was run throws an unhandled exception, then the result is also null. This method is applied asynchronously. If the method is run after the CoreWebView2.NavigationStarting event during a navigation, the script runs in the new document when loading it, around the time CoreWebView2.ContentLoading is run. This operation works even if CoreWebView2Settings.IsScriptEnabled is set to false.

ExecuteScriptWithResultAsync

IAsyncOperation<CoreWebView2ExecuteScriptResult> ExecuteScriptWithResultAsync(string javaScript)

Runs JavaScript code from the javaScript parameter in the current top-level document rendered in the WebView, The result of the execution is returned asynchronously in the CoreWebView2ExecuteScriptResult object which has methods and properties to obtain the successful result of script execution as well as any unhandled JavaScript exceptions.

GetDevToolsProtocolEventReceiver

CoreWebView2DevToolsProtocolEventReceiver GetDevToolsProtocolEventReceiver(string eventName)

Gets a DevTools Protocol event receiver that allows you to subscribe to a DevToolsProtocol event. For more information about DevToolsProtocol events description and event args, navigate to DevTools Protocol Viewer.

GetFaviconAsync

IAsyncOperation<IRandomAccessStream> GetFaviconAsync(CoreWebView2FaviconImageFormat format)

Get the downloaded Favicon image for the current page and copy it to the image stream. An IStream populated with the downloaded Favicon.

GoBack

void GoBack()

Navigates the WebView to the previous page in the navigation history.

GoForward

void GoForward()

Navigates the WebView to the next page in the navigation history.

Navigate

void Navigate(string uri)

Causes a navigation of the top level document to the specified URI. For more information, navigate to Navigation event. Note that this operation starts a navigation and the corresponding CoreWebView2.NavigationStarting event is raised sometime after Navigate runs.

NavigateToString

void NavigateToString(string htmlContent)

Initiates a navigation to htmlContent as source HTML of a new document. The htmlContent parameter may not be larger than 2 MB (2 * 1024 * 1024 bytes) in total size. The origin of the new page is about:blank.

webView.CoreWebView2.SetVirtualHostNameToFolderMapping(
    "appassets.example", "assets", CoreWebView2HostResourceAccessKind.DenyCors);
string htmlContent =
[]()"
    <head><link rel='stylesheet' href ='http://appassets.example/run.css' /></head>
    <body>
        <img src='http://appassets.example/grill.png' />
        <p><a href='http://appassets.example/winrt_test.txt'> Click me</a></p>
    </body>
";
webview.NavigateToString(htmlContent);

NavigateWithWebResourceRequest

void NavigateWithWebResourceRequest(CoreWebView2WebResourceRequest Request)

Navigates using a constructed CoreWebView2WebResourceRequest object. The headers in the CoreWebView2WebResourceRequest override headers added by WebView2 runtime except for Cookie headers. Method can only be either GET or POST. Provided post data will only be sent only if the method is POST and the uri scheme is HTTP(S).

OpenDefaultDownloadDialog

void OpenDefaultDownloadDialog()

Open the default download dialog. If the dialog is opened before there are recent downloads, the dialog shows all past downloads for the current profile. Otherwise, the dialog shows only the recent downloads with a "See more" button for past downloads. Calling this method raises the CoreWebView2.IsDefaultDownloadDialogOpenChanged event if the dialog was closed. No effect if the dialog is already open.

OpenDevToolsWindow

void OpenDevToolsWindow()

Opens the DevTools window for the current document in the WebView. Does nothing if run when the DevTools window is already open.

OpenTaskManagerWindow

void OpenTaskManagerWindow()

Opens the Browser Task Manager view as a new window in the foreground. If the Browser Task Manager is already open, this will bring it into the foreground. WebView2 currently blocks the Shift+Esc shortcut for opening the task manager. An end user can open the browser task manager manually via the Browser task manager entry of the DevTools window's title bar's context menu.

PostSharedBufferToScript

void PostSharedBufferToScript(CoreWebView2SharedBuffer sharedBuffer, CoreWebView2SharedBufferAccess access, string additionalDataAsJson)

Share a shared buffer object with script of the main frame in the WebView. The script will receive a sharedbufferreceived event from chrome.webview. The event arg for that event will have the following methods and properties.

Property	Description
getBuffer()	A method that returns an ArrayBuffer object with the backing content from the shared buffer.
additionalData	An object as the result of parsing `additionalDataAsJson` as JSON string. This property will be `undefined` if `additionalDataAsJson` is nullptr or empty string.
source	With a value set as `chrome.webview` object.

If access is CoreWebView2SharedBufferAccess.ReadOnly, the script will only have read access to the buffer. If the script tries to modify the content in a read only buffer, it will cause an access violation in WebView renderer process and crash the renderer process.

If the shared buffer is already closed, the API throws COMException with error code of RO_E_CLOSED. The script code should call chrome.webview.releaseBuffer with the shared buffer as the parameter to release underlying resources as soon as it does not need access to the shared buffer any more.

The application can post the same shared buffer object to multiple web pages or iframes, or post to the same web page or iframe multiple times. Each PostSharedBufferToScript will create a separate ArrayBuffer object with its own view of the memory and is separately released. The underlying shared memory will be released when all the views are released.

Sharing a buffer to script has security risk. You should only share buffer with trusted site. If a buffer is shared to a untrusted site, possible sensitive information could be leaked. If a buffer is shared as modifiable by the script and the script modifies it in an unexpected way, it could result in corrupted data that might even crash the application.

The example code shows how to send data to script for one time read only consumption.

PostWebMessageAsJson

void PostWebMessageAsJson(string webMessageAsJson, IVectorView<Object> additionalObjects)

Same as CoreWebView2.PostWebMessageAsJson, but also has support for posting DOM objects to page content. The event args is an instance of MessageEvent. The CoreWebView2Settings.IsWebMessageEnabled setting must be true or the message will not be sent. The event arg's data property of the event arg is the webMessageAsJson string parameter parsed as a JSON string into a JavaScript object. The event arg's source property of the event arg is a reference to the window.chrome.webview object. For information about sending messages from the HTML document in the WebView to the host, navigate to CoreWebView2.WebMessageReceived. The message is sent asynchronously. If a navigation occurs before the message is posted to the page, the message is not be sent. This property is retrieved in web content via the DOM MessageEvent additionalObjects property as an array-like list of DOM objects. Currently these type of objects can be the posted:

.NET / WinRT	DOM type
CoreWebView2FileSystemHandle	FileSystemHandle
`null`	null

The objects are posted to web content, following the structured-clone semantics, meaning only objects that can be cloned can be posted. They will also behave as if they had been created by the web content they are posted to. For example, if a FileSystemFileHandle is posted to a web content it can only be re-transferred via postMessage to other web content with the same origin. Warning: An app needs to be mindful when using this API to post DOM objects as this API provides the web content with unusual access to sensitive Web Platform features such as filesystem access! Similar to PostWebMessageAsJson, the app should check the CoreWebView2.Source property right before posting the message to ensure the message and objects will only be sent to the target web content that it expects to receive the DOM objects.

PostWebMessageAsJson

void PostWebMessageAsJson(string webMessageAsJson)

Posts the specified webMessageAsJson to the top level document in this WebView. The event args is an instance of MessageEvent. The CoreWebView2Settings.IsWebMessageEnabled setting must be true or the message will not be sent. The event arg's data property of the event arg is the webMessageAsJson string parameter parsed as a JSON string into a JavaScript object. The event arg's source property of the event arg is a reference to the window.chrome.webview object. For information about sending messages from the HTML document in the WebView to the host, navigate to CoreWebView2.WebMessageReceived. The message is sent asynchronously. If a navigation occurs before the message is posted to the page, the message is not be sent. Runs the message event of the window.chrome.webview of the top-level document. JavaScript in that document may subscribe and unsubscribe to the event using the following code:

window.chrome.webview.addEventListener('message', handler)
window.chrome.webview.removeEventListener('message', handler)

PostWebMessageAsString

void PostWebMessageAsString(string webMessageAsString)

Posts a message that is a simple string rather than a JSON string representation of a JavaScript object. This behaves in exactly the same manner as CoreWebView2.PostWebMessageAsJson, but the data property of the event arg of the window.chrome.webview message is a string with the same value as webMessageAsString. Use this instead of CoreWebView2.PostWebMessageAsJson if you want to communicate using simple strings rather than JSON objects.

PrintAsync

IAsyncOperation<CoreWebView2PrintStatus> PrintAsync(CoreWebView2PrintSettings printSettings)

Print the current web page asynchronously to the specified printer with the provided settings. See CoreWebView2PrintSettings for description of settings. Passing null for printSettings results in default print settings used.

The method will return CoreWebView2PrintStatus as CoreWebView2PrintStatus.PrinterUnavailable if printerName doesn't match with the name of any installed printers on the user OS. The method will throw ArgumentException if the caller provides invalid settings for a given printer.

The async Print operation completes when it finishes printing to the printer. Only one Printing operation can be in progress at a time. If Print is called while a CoreWebView2.PrintAsync or CoreWebView2.PrintToPdfAsync or CoreWebView2.PrintToPdfStreamAsync job is in progress, the IAsyncOperation throws exception. This is only for printing operation on one webview.

Error	PrintStatus	Notes
No	CoreWebView2PrintStatus.Succeeded	Print operation succeeded.
No	CoreWebView2PrintStatus.PrinterUnavailable	If specified printer is not found or printer status is not available, offline or error state.
No	CoreWebView2PrintStatus.OtherError	Print operation is failed.
ArgumentException	CoreWebView2PrintStatus.OtherError	If the caller provides invalid settings for the specified printer.
Exception	CoreWebView2PrintStatus.OtherError	Print operation is failed as printing job already in progress.

PrintToPdfAsync

IAsyncOperation<bool> PrintToPdfAsync(string ResultFilePath, CoreWebView2PrintSettings printSettings)

Print the current page to PDF asynchronously with the provided settings. See CoreWebView2PrintSettings for description of settings. Passing null for printSettings results in default print settings used.

Use resultFilePath to specify the path to the PDF file. The host should provide an absolute path, including file name. If the path points to an existing file, the file will be overwritten. If the path is not valid, the method fails.

The async PrintToPdf operation completes when the data has been written to the PDF file. If the application exits before printing is complete, the file is not saved. Only one PrintToPdf operation can be in progress at a time. If PrintToPdf is called while a print to PDF operation is in progress, the IAsyncOperation completes and returns false.

PrintToPdfStreamAsync

IAsyncOperation<IRandomAccessStream> PrintToPdfStreamAsync(CoreWebView2PrintSettings printSettings)

Provides the Pdf data of current web page asynchronously for the provided settings. Stream will be rewound to the start of the pdf data.

See CoreWebView2PrintSettings for description of settings. Passing null for printSettings results in default print settings used.

The async PrintToPdfStream operation completes when it finishes writing to the stream. Only one Printing operation can be in progress at a time. If CoreWebView2.PrintToPdfStreamAsync is called while a CoreWebView2.PrintToPdfStreamAsync or CoreWebView2.PrintToPdfAsync or CoreWebView2.PrintAsync job is in progress, the IAsyncOperation throws an exception. This is only for printing operation on one webview.

Reload

void Reload()

Reloads the current page. This is similar to navigating to the URI of current top level document including all navigation events firing and respecting any entries in the HTTP cache. But, the back or forward history will not be modified.

RemoveHostObjectFromScript

void RemoveHostObjectFromScript(string name)

Removes the host object specified by the name so that it is no longer accessible from JavaScript code in the WebView. While new access attempts are denied, if the object is already obtained by JavaScript code in the WebView, the JavaScript code continues to have access to that object. Running this method for a name that is already removed or never added fails.

RemoveScriptToExecuteOnDocumentCreated

void RemoveScriptToExecuteOnDocumentCreated(string id)

Removes the corresponding JavaScript added via CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync with the specified script ID. Both use CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync and this method in CoreWebView2.NewWindowRequested handler at the same time sometimes causes trouble. Since invalid scripts will be ignored, the script IDs you got may not be valid anymore.

RemoveWebResourceRequestedFilter

void RemoveWebResourceRequestedFilter(string uri, CoreWebView2WebResourceContext resourceContext, CoreWebView2WebResourceRequestSourceKinds requestSourceKinds)

This is an overload method that allows to unsubscribe from WebResourceRequested events received outside of main page.

RemoveWebResourceRequestedFilter

void RemoveWebResourceRequestedFilter(string uri, CoreWebView2WebResourceContext ResourceContext)

Warning: This method and are deprecated. Removes a matching WebResource filter that was previously added for the CoreWebView2.WebResourceRequested event. If the same filter was added multiple times, then it must need to be removed as many times as it was added for the removal to be effective.

Resume

void Resume()

Resumes the WebView so that it resumes activities on the web page. This API can be called while the WebView2 controller is invisible.

The app can interact with the WebView immediately after CoreWebView2.Resume.

WebView will be automatically resumed when it becomes visible.

SetVirtualHostNameToFolderMapping

void SetVirtualHostNameToFolderMapping(string hostName, string folderPath, CoreWebView2HostResourceAccessKind accessKind)

Sets a mapping between a virtual host name and a folder path to make available to web sites via that host name. After setting the mapping, documents loaded in the WebView can use HTTP or HTTPS URLs at the specified host name specified by hostName to access files in the local folder specified by folderPath. This mapping applies to both top-level document and iframe navigations as well as subresource references from a document. This also applies to dedicated and shared worker scripts but does not apply to service worker scripts.

Due to a current implementation limitation, media files accessed using virtual host name can be very slow to load.

As the resource loaders for the current page might have already been created and running, changes to the mapping might not be applied to the current page and a reload of the page is needed to apply the new mapping.

Both absolute and relative paths are supported for folderPath. Relative paths are interpreted as relative to the folder where the exe of the app is in. For example, after calling SetVirtualHostNameToFolderMapping("appassets.example", "assets", CoreWebView2HostResourceAccessKind.Deny);, navigating to https://appassets.example/my-local-file.html will show content from my-local-file.html in the assets subfolder located on disk under the same path as the app's executable file.

DOM elements that want to reference local files will have their host reference virtual host in the source. If there are multiple folders being used, define one unique virtual host per folder. You should typically choose virtual host names that are never used by real sites. If you own a domain such as example.com, another option is to use a subdomain reserved for the app (like my-app.example.com). RFC 6761 has reserved several special-use domain names that are guaranteed to not be used by real sites (for example, .example, .test, and .invalid). Note that using .local as the top-level domain name will work but can cause a delay during navigations. You should avoid using .local if you can. Apps should use distinct domain names when mapping folder from different sources that should be isolated from each other. For instance, the app might use app-file.example for files that ship as part of the app, and book1.example might be used for files containing books from a less trusted source that were previously downloaded and saved to the disk by the app. The host name used in the APIs is canonicalized using Chromium's host name parsing logic before being used internally. For more information see HTML5 2.6 URLs. All host names that are canonicalized to the same string are considered identical. For example, EXAMPLE.COM and example.com are treated as the same host name. An international host name and its Punycode-encoded host name are considered the same host name. There is no DNS resolution for host name and the trailing '.' is not normalized as part of canonicalization. Therefore example.com and example.com. are treated as different host names. Similarly, virtual-host-name and virtual-host-name.example.com are treated as different host names even if the machine has a DNS suffix of example.com. Specify the minimal cross-origin access necessary to run the app. If there is not a need to access local resources from other origins, use CoreWebView2HostResourceAccessKind.Deny. Setting the accessKind parameter does not adjust the app container permission for a folder.

webView.CoreWebView2.SetVirtualHostNameToFolderMapping(
    "appassets.example", "assets", CoreWebView2HostResourceAccessKind.DenyCors);
webView.Source = new Uri("https://appassets.example/index.html");

This in an example on how to embed a local image. For more information see CoreWebView2.NavigateToString.

webView.CoreWebView2.SetVirtualHostNameToFolderMapping(
    "appassets.example", "assets", CoreWebView2HostResourceAccessKind.DenyCors);
string c_navString = "<img src='http://appassets.example/wv2.png'/>";
webview.NavigateToString(c_navString);

ShowPrintUI

void ShowPrintUI(CoreWebView2PrintDialogKind printDialogKind)

Opens the print dialog to print the current web page. See CoreWebView2PrintDialogKind for descriptions of print dialog kinds.

Invoking browser or system print dialog doesn't open new print dialog if it is already open.

ShowSaveAsUIAsync

IAsyncOperation<CoreWebView2SaveAsUIResult> ShowSaveAsUIAsync()

Async method to programmatically trigger a Save As action for the currently loaded document.

Stop

void Stop()

Stops all navigations and pending resource fetches. Does not stop scripts.

TrySuspendAsync

IAsyncOperation<bool> TrySuspendAsync()

An app may call this API to have the WebView2 consume less memory. This is useful when a Win32 app becomes invisible, or when a Universal Windows Platform app is being suspended, during the suspended event handler before completing the suspended event.

The CoreWebView2Controller.IsVisible property must be false when the API is called. Otherwise, the API throws COMException with error code of HRESULT_FROM_WIN32(ERROR_INVALID_STATE).

Suspending is similar to putting a tab to sleep in the Edge browser. Suspending pauses WebView script timers and animations, minimizes CPU usage for the associated browser renderer process and allows the operating system to reuse the memory that was used by the renderer process for other processes.

Note that Suspend is best effort and considered completed successfully once the request is sent to browser renderer process. If there is a running script, the script will continue to run and the renderer process will be suspended after that script is done.

See Sleeping Tabs FAQ for conditions that might prevent WebView from being suspended. In those situations, the result of the async task is false.

The WebView will be automatically resumed when it becomes visible. Therefore, the app normally does not have to call CoreWebView2.Resume explicitly.

The app can call CoreWebView2.Resume and then CoreWebView2.TrySuspendAsync periodically for an invisible WebView so that the invisible WebView can sync up with latest data and the page ready to show fresh content when it becomes visible.

All WebView APIs can still be accessed when a WebView is suspended. Some APIs like Navigate will auto resume the WebView. To avoid unexpected auto resume, check CoreWebView2.IsSuspended property before calling APIs that might change WebView state.

Events

BasicAuthenticationRequested

BasicAuthenticationRequested event is raised when WebView encounters a Basic HTTP Authentication request as described in https://developer.mozilla.org/docs/Web/HTTP/Authentication, a Digest HTTP Authentication request as described in https://developer.mozilla.org/docs/Web/HTTP/Headers/Authorization#digest, an NTLM authentication or a Proxy Authentication request. The host can provide a response with credentials for the authentication or cancel the request. If the host sets the Cancel property to false but does not provide either UserName or Password properties on the Response property, then WebView2 will show the default authentication challenge dialog prompt to the user.

Type: TypedEventHandler<CoreWebView2, CoreWebView2BasicAuthenticationRequestedEventArgs>

ClientCertificateRequested

ClientCertificateRequested is raised when WebView2 is making a request to an HTTP server that needs a client certificate for HTTP authentication. Read more about HTTP client certificates at RFC 8446 The Transport Layer Security (TLS) Protocol Version 1.3. The host have several options for responding to client certificate requests:

Scenario	Handled	Cancel	SelectedCertificate
Respond to server with a certificate	True	False	MutuallyTrustedCertificate value
Respond to server without certificate	True	False	null
Display default client certificate selection dialog prompt	False	False	n/a
Cancel the request	n/a	True	n/a

If the host don't handle the event, WebView2 will show the default client certificate selection dialog prompt to the user.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ClientCertificateRequestedEventArgs>

ContainsFullScreenElementChanged

ContainsFullScreenElementChanged is raised when the CoreWebView2.ContainsFullScreenElement property changes. An HTML element inside the WebView may enter fullscreen to the size of the WebView or leave fullscreen. This event is useful when, for example, a video element requests to go fullscreen. The listener of this event may resize the WebView in response.

Type: TypedEventHandler<CoreWebView2, Object>

ContentLoading

ContentLoading is raised before any content is loaded, including scripts added with CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync. ContentLoading is not raised if a same page navigation occurs (such as through fragment navigations or history.pushState navigations). This operation follows the CoreWebView2.NavigationStarting and CoreWebView2.SourceChanged events and precedes the CoreWebView2.HistoryChanged and CoreWebView2.NavigationCompleted events.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ContentLoadingEventArgs>

ContextMenuRequested

ContextMenuRequested is raised when a context menu is requested by the user and the content inside WebView hasn't disabled context menus. The host has the option to create their own context menu with the information provided in the event or can add items to or remove items from WebView context menu. If the host doesn't handle the event, WebView will display the default context menu.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ContextMenuRequestedEventArgs>

DOMContentLoaded

DOMContentLoaded is raised when the initial HTML document has been parsed. This aligns with the the document's DOMContentLoaded event in HTML.

Type: TypedEventHandler<CoreWebView2, CoreWebView2DOMContentLoadedEventArgs>

DocumentTitleChanged

DocumentTitleChanged is raised when the CoreWebView2.DocumentTitle property changes and may be raised before or after the CoreWebView2.NavigationCompleted event.

Type: TypedEventHandler<CoreWebView2, Object>

DownloadStarting

DownloadStarting is raised when a download has begun, blocking the default download dialog, but not blocking the progress of the download. The host can choose to cancel a download, change the result file path, and hide the default download dialog. If download is not handled or canceled, the download is saved to the default path after the event completes with default download dialog shown.

Type: TypedEventHandler<CoreWebView2, CoreWebView2DownloadStartingEventArgs>

FaviconChanged

Raised when the Favicon has changed. This can include when a new page is loaded and thus by default no icon is set or the icon is set for the page by DOM or JavaScript. The first argument is the Webview2 which saw the changed Favicon and the second is null.

Type: TypedEventHandler<CoreWebView2, Object>

FrameCreated

FrameCreated is raised when a new iframe is created. Handle this event to get access to CoreWebView2Frame objects. Use the CoreWebView2Frame.Destroyed to listen for when this iframe goes away.

Type: TypedEventHandler<CoreWebView2, CoreWebView2FrameCreatedEventArgs>

FrameNavigationCompleted

FrameNavigationCompleted is raised when a child frame has completely loaded (body.onload has been raised) or loading stopped with error.

Type: TypedEventHandler<CoreWebView2, CoreWebView2NavigationCompletedEventArgs>

FrameNavigationStarting

FrameNavigationStarting is raised when a child frame in the WebView requests permission to navigate to a different URI. Redirects raise this operation as well, and the navigation id is the same as the original one. You may block corresponding navigations until the event handler returns.

Type: TypedEventHandler<CoreWebView2, CoreWebView2NavigationStartingEventArgs>

HistoryChanged

HistoryChanged is raised for changes to joint session history, which consists of top-level and manual frame navigations. Use HistoryChanged to verify that the CoreWebView2.CanGoBack or CoreWebView2.CanGoForward value has changed. HistoryChanged is also raised for using CoreWebView2.GoBack or CoreWebView2.GoForward. HistoryChanged is raised after CoreWebView2.SourceChanged and CoreWebView2.ContentLoading. CanGoBack is false for navigations initiated through CoreWebView2Frame APIs if there has not yet been a user gesture.

Type: TypedEventHandler<CoreWebView2, Object>

IsDefaultDownloadDialogOpenChanged

Raised when the CoreWebView2.IsDefaultDownloadDialogOpen property changes. This event comes after the CoreWebView2.DownloadStarting event. Setting the CoreWebView2DownloadStartingEventArgs.Handled property disables the default download dialog and ensures that this event is never raised.

Type: TypedEventHandler<CoreWebView2, Object>

IsDocumentPlayingAudioChanged

IsDocumentPlayingAudioChanged is raised when document starts or stops playing audio.

Type: TypedEventHandler<CoreWebView2, Object>

IsMutedChanged

IsMutedChanged is raised when the mute state changes.

Type: TypedEventHandler<CoreWebView2, Object>

LaunchingExternalUriScheme

LaunchingExternalUriScheme is raised when a navigation request is made to a URI scheme that is registered with the OS. The CoreWebView2.LaunchingExternalUriScheme event handler may suppress the default dialog or replace the default dialog with a custom dialog. If a CoreWebView2Deferral (unresolved reference) is not taken on the event args, the external URI scheme launch is blocked until the event handler returns. If a deferral is taken, the external URI scheme launch is blocked until the CoreWebView2Deferral (unresolved reference) is completed. The host also has the option to cancel the URI scheme launch.

The CoreWebView2.NavigationStarting and CoreWebView2.NavigationCompleted events will be raised, regardless of whether the CoreWebView2NavigationStartingEventArgs.Cancel property is set to true or false. The CoreWebView2.NavigationCompleted event will be raised with the CoreWebView2NavigationCompletedEventArgs.IsSuccess property set to false and the CoreWebView2NavigationCompletedEventArgs.WebErrorStatus property set to CoreWebView2WebErrorStatus.ConnectionAborted regardless of whether the host sets the CoreWebView2LaunchingExternalUriSchemeEventArgs.Cancel property. The CoreWebView2.SourceChanged, CoreWebView2.ContentLoading and CoreWebView2.HistoryChanged events will not be raised for this navigation to the external URI scheme regardless of the CoreWebView2NavigationStartingEventArgs.Cancel property. The CoreWebView2.LaunchingExternalUriScheme event will be raised after the CoreWebView2.NavigationStarting event and before the CoreWebView2.NavigationCompleted event.

The default CoreWebView2Settings will also be updated upon navigation to an external URI scheme. If a setting on the CoreWebView2Settings interface has been changed, navigating to an external URI scheme will trigger the CoreWebView2Settings to update.

The WebView2 may not display the default dialog based on user settings, browser settings, and whether the origin is determined as a trustworthy origin; however, the event will still be raised. If the request is initiated by a cross-origin frame without a user gesture, the request will be blocked and the LaunchingExternalUriScheme event will not be raised. A URI scheme may be blocked for safety reasons. In this case the LaunchingExternalUriScheme event will not be raised. The default dialog may show an "always allow" checkbox which allows the user to opt-in to relaxed security (i.e. skipping future default dialogs) for the combination of the URI scheme and the origin of the page initiating this external URI scheme launch. The checkbox is offered so long as the group policy to show the checkbox is not explicitly disabled and there is a trustworthy initiating origin. If the user has checked this box, future attempts to launch this URI scheme will still raise the event.

Type: TypedEventHandler<CoreWebView2, CoreWebView2LaunchingExternalUriSchemeEventArgs>

NavigationCompleted

NavigationCompleted is raised when the WebView has completely loaded (body.onload has been raised) or loading stopped with error.

Type: TypedEventHandler<CoreWebView2, CoreWebView2NavigationCompletedEventArgs>

NavigationStarting

NavigationStarting is raised when the WebView main frame is requesting permission to navigate to a different URI. Redirects raise this event as well, and the navigation id is the same as the original one. You may block corresponding navigations until the event handler returns.

Type: TypedEventHandler<CoreWebView2, CoreWebView2NavigationStartingEventArgs>

NewWindowRequested

NewWindowRequested is raised when content inside the WebView requests to open a new window, such as through window.open(). The app can pass a target WebView that is considered the opened window or mark the event as CoreWebView2NewWindowRequestedEventArgs.Handled, in which case WebView2 does not open a window. If either Handled or CoreWebView2NewWindowRequestedEventArgs.NewWindow properties are not set, the target content will be opened on a popup window. If a deferral is not taken on the event args, scripts that resulted in the new window that are requested are blocked until the event handler returns. If a deferral is taken, then scripts are blocked until the deferral is completed.

On Hololens 2, if the CoreWebView2NewWindowRequestedEventArgs.NewWindow property is not set and the CoreWebView2NewWindowRequestedEventArgs.Handled property is not set to true, the WebView2 will navigate to the CoreWebView2NewWindowRequestedEventArgs.Uri. If either of these properties are set, the WebView2 will not navigate to the CoreWebView2NewWindowRequestedEventArgs.Uri and the the CoreWebView2.NewWindowRequested event will continue as normal.

Type: TypedEventHandler<CoreWebView2, CoreWebView2NewWindowRequestedEventArgs>

NotificationReceived

NotificationReceived is raised when a non-persistent notification is received.

Type: TypedEventHandler<CoreWebView2, CoreWebView2NotificationReceivedEventArgs>

PermissionRequested

PermissionRequested is raised when content in a WebView requests permission to access some privileged resources. If a deferral is not taken on the event args, the subsequent scripts are blocked until the event handler returns. If a deferral is taken, the scripts are blocked until the deferral is completed.

Type: TypedEventHandler<CoreWebView2, CoreWebView2PermissionRequestedEventArgs>

ProcessFailed

ProcessFailed is raised when any of the processes in the WebView2 Process Group encounters one of the following conditions:

Condition	Details
Unexpected exit	The process indicated by the event args has exited unexpectedly (usually due to a crash). The failure might or might not be recoverable and some failures are auto-recoverable.
Unresponsiveness	The process indicated by the event args has become unresponsive to user input. This is only reported for renderer processes, and will run every few seconds until the process becomes responsive again.

Note: When the failing process is the browser process, a CoreWebView2Environment.BrowserProcessExited event will run too.

Your application can use CoreWebView2ProcessFailedEventArgs to identify which condition and process the event is for, and to collect diagnostics and handle recovery if necessary. For more details about which cases need to be handled by your application, see CoreWebView2ProcessFailedKind.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ProcessFailedEventArgs>

SaveAsUIShowing

SaveAsUIShowing is raised when browser trys to open a save as dialog. It includes opening dialog manually from context menu or programmatically from CoreWebView2.ShowSaveAsUIAsync.

Type: TypedEventHandler<CoreWebView2, CoreWebView2SaveAsUIShowingEventArgs>

SaveFileSecurityCheckStarting

This event will be raised during system FileTypePolicy checking the dangerous file extension list. Developers can specify their own logic for determining whether to allow a particular type of file to be saved from the document origin URI. Developers can also determine the save decision based on other criteria. Here are two properties in CoreWebView2SaveFileSecurityCheckStartingEventArgs to manage the decision, CoreWebView2SaveFileSecurityCheckStartingEventArgs.CancelSave and CoreWebView2SaveFileSecurityCheckStartingEventArgs.SuppressDefaultPolicy. Table of Properties' value and result:

CancelSave	SuppressDefaultPolicy	Result
False	False	Perform the default policy check. It may show the security warning UI if the file extension is dangerous.
False	True	Skip the default policy check and the possible security warning. Start saving or downloading.
True	Any	Skip the default policy check and the possible security warning. Abort save or download.

Type: TypedEventHandler<CoreWebView2, CoreWebView2SaveFileSecurityCheckStartingEventArgs>

ScreenCaptureStarting

ScreenCaptureStarting event is raised when the Screen Capture API is requested by the user using getDisplayMedia(). If a deferral is not taken on the event args, the subsequent scripts are blocked until the event handler returns. If a deferral is taken, the scripts are blocked until the deferral is completed.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ScreenCaptureStartingEventArgs>

ScriptDialogOpening

ScriptDialogOpening is raised when a JavaScript dialog (alert, confirm, prompt, or beforeunload) displays for the WebView. This event only is raised if the CoreWebView2Settings.AreDefaultScriptDialogsEnabled property is set to false. This event suppresses dialogs or replaces default dialogs with custom dialogs.

If a deferral is not taken on the event args, the subsequent scripts are blocked until the event handler returns. If a deferral is taken, the scripts are blocked until the deferral is completed.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ScriptDialogOpeningEventArgs>

ServerCertificateErrorDetected

The ServerCertificateErrorDetected event is raised when the WebView2 cannot verify server's digital certificate while loading a web page. This event will raise for all web resources and follows the CoreWebView2.WebResourceRequested event.

If you don't handle the event, WebView2 will show the default TLS interstitial error page to the user for navigations, and for non-navigations the web request is cancelled.

Note that WebView2 before raising ServerCertificateErrorDetected raises a CoreWebView2.NavigationCompleted event with CoreWebView2NavigationCompletedEventArgs.IsSuccess as FALSE and any of the below WebErrorStatuses that indicate a certificate failure.

CoreWebView2WebErrorStatus.CertificateCommonNameIsIncorrect
CoreWebView2WebErrorStatus.CertificateExpired
CoreWebView2WebErrorStatus.ClientCertificateContainsErrors
CoreWebView2WebErrorStatus.CertificateRevoked
CoreWebView2WebErrorStatus.CertificateIsInvalid

For more details see CoreWebView2NavigationCompletedEventArgs.IsSuccess and handle ServerCertificateErrorDetected event or show the default TLS interstitial error page to the user according to the app needs.

WebView2 caches the response when action is CoreWebView2ServerCertificateErrorAction.AlwaysAllow for the RequestUri's host and the server certificate in the session and the CoreWebView2.ServerCertificateErrorDetected event won't be raised again.

To raise the event again you must clear the cache using CoreWebView2.ClearServerCertificateErrorActionsAsync.

Type: TypedEventHandler<CoreWebView2, CoreWebView2ServerCertificateErrorDetectedEventArgs>

SourceChanged

SourceChanged is raised when the CoreWebView2.Source property changes. SourceChanged is raised when navigating to a different site or fragment navigations. It is not raised for other types of navigations such as page refreshes or history.pushState with the same URL as the current page. This event is raised before CoreWebView2.ContentLoading for navigation to a new document.

Type: TypedEventHandler<CoreWebView2, CoreWebView2SourceChangedEventArgs>

StatusBarTextChanged

StatusBarTextChanged event is raised when the text in the Window.statusbar changes. When the event is fired use the property CoreWebView2.StatusBarText to get the current statusbar text. Events which cause causes can be anything from hover, url events, and others. There is not a finite list on how to cause the statusbar to change. The developer must create the status bar and set the text.

Type: TypedEventHandler<CoreWebView2, Object>

WebMessageReceived

WebMessageReceived is raised when the CoreWebView2Settings.IsWebMessageEnabled setting is set and the top-level document of the WebView runs window.chrome.webview.postMessage or window.chrome.webview.postMessageWithAdditionalObjects. The postMessage function is void postMessage(object) where object is any object supported by JSON conversion. When postMessage is called, the handler's Invoke method will be called with the object parameter postMessage converted to a JSON string. If the same page calls postMessage multiple times, the corresponding WebMessageReceived events are guaranteed to be fired in the same order. However, if multiple frames call postMessage, there is no guaranteed order. In addition, WebMessageReceived events caused by calls to postMessage are not guaranteed to be sequenced with events caused by DOM APIs. For example, if the page runs chrome.webview.postMessage("message"); window.open(); then the CoreWebView2.NewWindowRequested event might be fired before the WebMessageReceived event. If you need the WebMessageReceived event to happen before anything else, then in the WebMessageReceived handler you can post a message back to the page and have the page wait until it receives that message before continuing.


Type: TypedEventHandler<CoreWebView2, CoreWebView2WebMessageReceivedEventArgs>
WebResourceRequested
WebResourceRequested is raised when the WebView is performing a URL request to a matching URL and resource context filter that was added with CoreWebView2.AddWebResourceRequestedFilter(string, CoreWebView2WebResourceContext, CoreWebView2WebResourceRequestSourceKinds).
At least one filter must be added for the event to be raised.
The web resource requested may be blocked until the event handler returns if a deferral is not taken on the event args. If a deferral is taken, then the web resource requested is blocked until the deferral is completed.
If this event is subscribed in the CoreWebView2.NewWindowRequested handler it should be called after the new window is set. For more details see CoreWebView2NewWindowRequestedEventArgs.NewWindow.
This event is by default raised for file, http, and https URI schemes. This is also raised for registered custome URI schemes. See CoreWebView2CustomSchemeRegistration for more details.
Type: TypedEventHandler<CoreWebView2, CoreWebView2WebResourceRequestedEventArgs>
WebResourceResponseReceived
WebResourceResponseReceived is raised when the WebView receives the response for a request for a web resource (any URI resolution performed by the WebView; such as HTTP/HTTPS, file and data requests from redirects, navigations, declarations in HTML, implicit Favicon lookups, and fetch API usage in the document).
The host app can use this event to view the actual request and response for a web resource. There is no guarantee about the order in which the WebView processes the response and the host app's handler runs. The app's handler will not block the WebView from processing the response.
The event args include the CoreWebView2WebResourceRequest as sent by the wire and CoreWebView2WebResourceResponse received, including any additional headers added by the network stack that were not be included as part of the associated CoreWebView2.WebResourceRequested event, such as Authentication headers.
Type: TypedEventHandler<CoreWebView2, CoreWebView2WebResourceResponseReceivedEventArgs>
WindowCloseRequested
WindowCloseRequested is raised when content inside the WebView requested to close the window, such as after window.close() is run.
The app should close the WebView and related app window if that makes sense to the app.
After the first window.close() call, this event may not fire for any immediate back to back window.close() calls.
Type: TypedEventHandler<CoreWebView2, Object>
Referenced by

CoreWebView2Controller
CoreWebView2DevToolsProtocolEventReceiver
CoreWebView2NewWindowRequestedEventArgs

Share via

CoreWebView2 Class

Summary

Properties

BrowserProcessId

CanGoBack

CanGoForward

ContainsFullScreenElement

CookieManager

DefaultDownloadDialogCornerAlignment

DefaultDownloadDialogMargin

DocumentTitle

Environment

FaviconUri

FrameId

IsDefaultDownloadDialogOpen

IsDocumentPlayingAudio

IsMuted

IsSuspended

MemoryUsageTargetLevel

Profile

Settings

Source

StatusBarText

Methods

AddHostObjectToScript

AddScriptToExecuteOnDocumentCreatedAsync

AddWebResourceRequestedFilter

AddWebResourceRequestedFilter

CallDevToolsProtocolMethodAsync

CallDevToolsProtocolMethodForSessionAsync

CapturePreviewAsync

ClearServerCertificateErrorActionsAsync

ClearVirtualHostNameToFolderMapping

CloseDefaultDownloadDialog

ExecuteScriptAsync

ExecuteScriptWithResultAsync

GetDevToolsProtocolEventReceiver

GetFaviconAsync

GoBack

GoForward

Navigate

NavigateToString

NavigateWithWebResourceRequest

OpenDefaultDownloadDialog

OpenDevToolsWindow

OpenTaskManagerWindow

PostSharedBufferToScript

PostWebMessageAsJson

PostWebMessageAsJson

PostWebMessageAsString

PrintAsync

PrintToPdfAsync

PrintToPdfStreamAsync

Reload

RemoveHostObjectFromScript

RemoveScriptToExecuteOnDocumentCreated

RemoveWebResourceRequestedFilter

RemoveWebResourceRequestedFilter

Resume

SetVirtualHostNameToFolderMapping

ShowPrintUI

ShowSaveAsUIAsync

Stop

TrySuspendAsync

Events

BasicAuthenticationRequested

ClientCertificateRequested

ContainsFullScreenElementChanged

ContentLoading

ContextMenuRequested

DOMContentLoaded

DocumentTitleChanged

DownloadStarting

FaviconChanged

FrameCreated

FrameNavigationCompleted

FrameNavigationStarting

HistoryChanged

IsDefaultDownloadDialogOpenChanged