interface ICoreWebView2Environment

interface ICoreWebView2Environment
  : public IUnknown

Represents the WebView2 Environment.

Summary

Members	Descriptions
add_NewBrowserVersionAvailable	Add an event handler for the NewBrowserVersionAvailable event.
CreateCoreWebView2Controller	Asynchronously create a new WebView.
CreateWebResourceResponse	Create a new web resource response object.
get_BrowserVersionString	The browser version info of the current ICoreWebView2Environment, including channel name if it is not the WebView2 Runtime.
remove_NewBrowserVersionAvailable	Remove an event handler previously added with add_NewBrowserVersionAvailable.

WebViews created from an environment run on the browser process specified with environment parameters and objects created from an environment should be used in the same environment. Using it in different environments are not guaranteed to be compatible and may fail.

Applies to

Product	Introduced
WebView2 Win32	0.9.430
WebView2 Win32 Prerelease	0.9.488

Members

add_NewBrowserVersionAvailable

Add an event handler for the NewBrowserVersionAvailable event.

public HRESULT add_NewBrowserVersionAvailable(ICoreWebView2NewBrowserVersionAvailableEventHandler * eventHandler, EventRegistrationToken * token)

NewBrowserVersionAvailable runs when a newer version of the WebView2 Runtime is installed and available using WebView2. To use the newer version of the browser you must create a new environment and WebView. The event only runs for new version from the same WebView2 Runtime from which the code is running. When not running with installed WebView2 Runtime, no event is run.

Because a user data folder is only able to be used by one browser process at a time, if you want to use the same user data folder in the WebView using the new version of the browser, you must close the environment and instance of WebView that are using the older version of the browser first. Or simply prompt the user to restart the app.

    // After the environment is successfully created,
    // register a handler for the NewBrowserVersionAvailable event.
    // This handler tells when there is a new Edge version available on the machine.
    CHECK_FAILURE(m_webViewEnvironment->add_NewBrowserVersionAvailable(
        Callback<ICoreWebView2NewBrowserVersionAvailableEventHandler>(
            [this](ICoreWebView2Environment* sender, IUnknown* args) -> HRESULT
            {
                // Don't block the event handler with a message box
                RunAsync(
                    [this]
                    {
                        std::wstring message =
                            L"We detected there is a new version for the browser.";
                        if (m_webView)
                        {
                            message += L"Do you want to restart the app? \n\n";
                            message +=
                                L"Click No if you only want to re-create the webviews. \n";
                            message += L"Click Cancel for no action. \n";
                        }
                        int response = MessageBox(
                            m_mainWindow, message.c_str(), L"New available version",
                            m_webView ? MB_YESNOCANCEL : MB_OK);

                        if (response == IDYES)
                        {
                            RestartApp();
                        }
                        else if (response == IDNO)
                        {
                            ReinitializeWebViewWithNewBrowser();
                        }
                        else
                        {
                            // do nothing
                        }
                    });

                return S_OK;
            })
            .Get(),
        nullptr));

CreateCoreWebView2Controller

Asynchronously create a new WebView.

public HRESULT CreateCoreWebView2Controller(HWND parentWindow, ICoreWebView2CreateCoreWebView2ControllerCompletedHandler * handler)

parentWindow is the HWND in which the WebView should be displayed and from which receive input. The WebView adds a child window to the provided window before this function returns. Z-order and other things impacted by sibling window order are affected accordingly. If you want to move the WebView to a different parent after it has been created, you must call put_ParentWindow to update tooltip positions, accessibility trees, and such.

HWND_MESSAGE is a valid parameter for parentWindow for an invisible WebView for Windows 8 and above. In this case the window will never become visible. You are not able to reparent the window after you have created the WebView. This is not supported in Windows 7 or below. Passing this parameter in Windows 7 or below will return ERROR_INVALID_WINDOW_HANDLE in the controller callback.

It is recommended that the app set Application User Model ID for the process or the app window. If none is set, during WebView creation a generated Application User Model ID is set to root window of parentWindow.

// Create or recreate the WebView and its environment.
void AppWindow::InitializeWebView()
{
    // To ensure browser switches get applied correctly, we need to close
    // the existing WebView. This will result in a new browser process
    // getting created which will apply the browser switches.
    CloseWebView();
    m_dcompDevice = nullptr;
    m_wincompCompositor = nullptr;
    LPCWSTR subFolder = nullptr;

    if (m_creationModeId == IDM_CREATION_MODE_VISUAL_DCOMP ||
        m_creationModeId == IDM_CREATION_MODE_TARGET_DCOMP)
    {
        HRESULT hr = DCompositionCreateDevice2(nullptr, IID_PPV_ARGS(&m_dcompDevice));
        if (!SUCCEEDED(hr))
        {
            MessageBox(
                m_mainWindow,
                L"Attempting to create WebView using DComp Visual is not supported.\r\n"
                "DComp device creation failed.\r\n"
                "Current OS may not support DComp.",
                L"Create with Windowless DComp Visual Failed", MB_OK);
            return;
        }
    }
    else if (m_creationModeId == IDM_CREATION_MODE_VISUAL_WINCOMP)
    {
        HRESULT hr = TryCreateDispatcherQueue();
        if (!SUCCEEDED(hr))
        {
            MessageBox(
                m_mainWindow,
                L"Attempting to create WebView using WinComp Visual is not supported.\r\n"
                "WinComp compositor creation failed.\r\n"
                "Current OS may not support WinComp.",
                L"Create with Windowless WinComp Visual Failed", MB_OK);
            return;
        }
        m_wincompCompositor = winrtComp::Compositor();
    }

    std::wstring args;
    args.append(L"--enable-features=ThirdPartyStoragePartitioning,PartitionedCookies");
    auto options = Microsoft::WRL::Make<CoreWebView2EnvironmentOptions>();
    options->put_AdditionalBrowserArguments(args.c_str());
    CHECK_FAILURE(
        options->put_AllowSingleSignOnUsingOSPrimaryAccount(m_AADSSOEnabled ? TRUE : FALSE));
    CHECK_FAILURE(options->put_ExclusiveUserDataFolderAccess(
        m_ExclusiveUserDataFolderAccess ? TRUE : FALSE));
    if (!m_language.empty())
        CHECK_FAILURE(options->put_Language(m_language.c_str()));
    CHECK_FAILURE(options->put_IsCustomCrashReportingEnabled(
        m_CustomCrashReportingEnabled ? TRUE : FALSE));

    Microsoft::WRL::ComPtr<ICoreWebView2EnvironmentOptions4> options4;
    if (options.As(&options4) == S_OK)
    {
        const WCHAR* allowedOrigins[1] = {L"https://*.example.com"};

        auto customSchemeRegistration =
            Microsoft::WRL::Make<CoreWebView2CustomSchemeRegistration>(L"custom-scheme");
        customSchemeRegistration->SetAllowedOrigins(1, allowedOrigins);
        auto customSchemeRegistration2 =
            Microsoft::WRL::Make<CoreWebView2CustomSchemeRegistration>(L"wv2rocks");
        customSchemeRegistration2->put_TreatAsSecure(TRUE);
        customSchemeRegistration2->SetAllowedOrigins(1, allowedOrigins);
        customSchemeRegistration2->put_HasAuthorityComponent(TRUE);
        auto customSchemeRegistration3 =
            Microsoft::WRL::Make<CoreWebView2CustomSchemeRegistration>(
                L"custom-scheme-not-in-allowed-origins");
        ICoreWebView2CustomSchemeRegistration* registrations[3] = {
            customSchemeRegistration.Get(), customSchemeRegistration2.Get(),
            customSchemeRegistration3.Get()};
        options4->SetCustomSchemeRegistrations(
            2, static_cast<ICoreWebView2CustomSchemeRegistration**>(registrations));
    }

    Microsoft::WRL::ComPtr<ICoreWebView2EnvironmentOptions5> options5;
    if (options.As(&options5) == S_OK)
    {
        CHECK_FAILURE(
            options5->put_EnableTrackingPrevention(m_TrackingPreventionEnabled ? TRUE : FALSE));
    }

    Microsoft::WRL::ComPtr<ICoreWebView2EnvironmentOptions6> options6;
    if (options.As(&options6) == S_OK)
    {
        CHECK_FAILURE(options6->put_AreBrowserExtensionsEnabled(TRUE));
    }

    Microsoft::WRL::ComPtr<ICoreWebView2EnvironmentOptions8> options8;
    if (options.As(&options8) == S_OK)
    {
        COREWEBVIEW2_SCROLLBAR_STYLE style = COREWEBVIEW2_SCROLLBAR_STYLE_FLUENT_OVERLAY;
        CHECK_FAILURE(options8->put_ScrollBarStyle(style));
    }

    HRESULT hr = CreateCoreWebView2EnvironmentWithOptions(
        subFolder, m_userDataFolder.c_str(), options.Get(),
        Callback<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>(
            this, &AppWindow::OnCreateEnvironmentCompleted)
            .Get());
    if (!SUCCEEDED(hr))
    {
        switch (hr)
        {
        case HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND):
        {
            MessageBox(
                m_mainWindow,
                L"Couldn't find Edge WebView2 Runtime. "
                "Do you have a version installed?",
                nullptr, MB_OK);
        }
        break;
        case HRESULT_FROM_WIN32(ERROR_FILE_EXISTS):
        {
            MessageBox(
                m_mainWindow,
                L"User data folder cannot be created because a file with the same name already "
                L"exists.",
                nullptr, MB_OK);
        }
        break;
        case E_ACCESSDENIED:
        {
            MessageBox(
                m_mainWindow, L"Unable to create user data folder, Access Denied.", nullptr,
                MB_OK);
        }
        break;
        case E_FAIL:
        {
            MessageBox(m_mainWindow, L"Edge runtime unable to start", nullptr, MB_OK);
        }
        break;
        default:
        {
            ShowFailure(hr, L"Failed to create WebView2 environment");
        }
        }
    }
}
// This is the callback passed to CreateWebViewEnvironmentWithOptions.
// Here we simply create the WebView.
HRESULT AppWindow::OnCreateEnvironmentCompleted(
    HRESULT result, ICoreWebView2Environment* environment)
{
    if (result != S_OK)
    {
        ShowFailure(result, L"Failed to create environment object.");
        return S_OK;
    }
    m_webViewEnvironment = environment;

    if (m_webviewOption.entry == WebViewCreateEntry::EVER_FROM_CREATE_WITH_OPTION_MENU ||
        m_creationModeId == IDM_CREATION_MODE_HOST_INPUT_PROCESSING
    )
    {
        return CreateControllerWithOptions();
    }
    auto webViewEnvironment3 = m_webViewEnvironment.try_query<ICoreWebView2Environment3>();

    if (webViewEnvironment3 && (m_dcompDevice || m_wincompCompositor))
    {
        CHECK_FAILURE(webViewEnvironment3->CreateCoreWebView2CompositionController(
            m_mainWindow,
            Callback<ICoreWebView2CreateCoreWebView2CompositionControllerCompletedHandler>(
                [this](
                    HRESULT result,
                    ICoreWebView2CompositionController* compositionController) -> HRESULT
                {
                    auto controller =
                        wil::com_ptr<ICoreWebView2CompositionController>(compositionController)
                            .query<ICoreWebView2Controller>();
                    return OnCreateCoreWebView2ControllerCompleted(result, controller.get());
                })
                .Get()));
    }
    else
    {
        CHECK_FAILURE(m_webViewEnvironment->CreateCoreWebView2Controller(
            m_mainWindow, Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
                              this, &AppWindow::OnCreateCoreWebView2ControllerCompleted)
                              .Get()));
    }

    return S_OK;
}

It is recommended that the app handles restart manager messages, to gracefully restart it in the case when the app is using the WebView2 Runtime from a certain installation and that installation is being uninstalled. For example, if a user installs a version of the WebView2 Runtime and opts to use another version of the WebView2 Runtime for testing the app, and then uninstalls the 1st version of the WebView2 Runtime without closing the app, the app restarts to allow un-installation to succeed.

    case WM_QUERYENDSESSION:
    {
        // yes, we can shut down
        // Register how we might be restarted
        RegisterApplicationRestart(L"--restore", RESTART_NO_CRASH | RESTART_NO_HANG);
        *result = TRUE;
        return true;
    }
    break;
    case WM_ENDSESSION:
    {
        if (wParam == TRUE)
        {
            // save app state and exit.
            PostQuitMessage(0);
            return true;
        }
    }
    break;

The app should retry CreateCoreWebView2Controller upon failure, unless the error code is HRESULT_FROM_WIN32(ERROR_INVALID_STATE). When the app retries CreateCoreWebView2Controller upon failure, it is recommended that the app restarts from creating a new WebView2 Environment. If a WebView2 Runtime update happens, the version associated with a WebView2 Environment may have been removed and causing the object to no longer work. Creating a new WebView2 Environment works since it uses the latest version.

WebView creation fails with HRESULT_FROM_WIN32(ERROR_INVALID_STATE) if a running instance using the same user data folder exists, and the Environment objects have different EnvironmentOptions. For example, if a WebView was created with one language, an attempt to create a WebView with a different language using the same user data folder will fail.

The creation will fail with E_ABORT if parentWindow is destroyed before the creation is finished. If this is caused by a call to DestroyWindow, the creation completed handler will be invoked before DestroyWindow returns, so you can use this to cancel creation and clean up resources synchronously when quitting a thread.

In rare cases the creation can fail with E_UNEXPECTED if runtime does not have permissions to the user data folder.

CreateWebResourceResponse

Create a new web resource response object.

public HRESULT CreateWebResourceResponse(IStream * content, int statusCode, LPCWSTR reasonPhrase, LPCWSTR headers, ICoreWebView2WebResourceResponse ** response)

The headers parameter is the raw response header string delimited by newline. It is also possible to create this object with null headers string and then use the ICoreWebView2HttpResponseHeaders to construct the headers line by line. For more information about other parameters, navigate to ICoreWebView2WebResourceResponse.

        if (m_blockImages)
        {
            m_webView->AddWebResourceRequestedFilter(
                L"*", COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE);
            CHECK_FAILURE(m_webView->add_WebResourceRequested(
                Callback<ICoreWebView2WebResourceRequestedEventHandler>(
                    [this](
                        ICoreWebView2* sender, ICoreWebView2WebResourceRequestedEventArgs* args)
                    {
                        COREWEBVIEW2_WEB_RESOURCE_CONTEXT resourceContext;
                        CHECK_FAILURE(args->get_ResourceContext(&resourceContext));
                        // Ensure that the type is image
                        if (resourceContext != COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE)
                        {
                            return E_INVALIDARG;
                        }
                        // Override the response with an empty one to block the image.
                        // If put_Response is not called, the request will
                        // continue as normal.
                        wil::com_ptr<ICoreWebView2WebResourceResponse> response;
                        wil::com_ptr<ICoreWebView2Environment> environment;
                        wil::com_ptr<ICoreWebView2_2> webview2;
                        CHECK_FAILURE(m_webView->QueryInterface(IID_PPV_ARGS(&webview2)));
                        CHECK_FAILURE(webview2->get_Environment(&environment));
                        CHECK_FAILURE(environment->CreateWebResourceResponse(
                            nullptr, 403 /*NoContent*/, L"Blocked", L"Content-Type: image/jpeg",
                            &response));
                        CHECK_FAILURE(args->put_Response(response.get()));
                        return S_OK;
                    })
                    .Get(),
                &m_webResourceRequestedTokenForImageBlocking));
        }
        else
        {
            CHECK_FAILURE(m_webView->remove_WebResourceRequested(
                m_webResourceRequestedTokenForImageBlocking));
        }

        if (m_replaceImages)
        {
            m_webView->AddWebResourceRequestedFilter(
                L"*", COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE);
            CHECK_FAILURE(m_webView->add_WebResourceRequested(
                Callback<ICoreWebView2WebResourceRequestedEventHandler>(
                    [this](
                        ICoreWebView2* sender, ICoreWebView2WebResourceRequestedEventArgs* args)
                    {
                        COREWEBVIEW2_WEB_RESOURCE_CONTEXT resourceContext;
                        CHECK_FAILURE(args->get_ResourceContext(&resourceContext));
                        // Ensure that the type is image
                        if (resourceContext != COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE)
                        {
                            return E_INVALIDARG;
                        }
                        // Override the response with an another image.
                        // If put_Response is not called, the request will
                        // continue as normal.
                        // It's not required for this scenario, but generally you should examine
                        // relevant HTTP request headers just like an HTTP server would do when
                        // producing a response stream.
                        wil::com_ptr<IStream> stream;
                        CHECK_FAILURE(SHCreateStreamOnFileEx(
                            L"assets/EdgeWebView2-80.jpg", STGM_READ, FILE_ATTRIBUTE_NORMAL,
                            FALSE, nullptr, &stream));
                        wil::com_ptr<ICoreWebView2WebResourceResponse> response;
                        wil::com_ptr<ICoreWebView2Environment> environment;
                        wil::com_ptr<ICoreWebView2_2> webview2;
                        CHECK_FAILURE(m_webView->QueryInterface(IID_PPV_ARGS(&webview2)));
                        CHECK_FAILURE(webview2->get_Environment(&environment));
                        CHECK_FAILURE(environment->CreateWebResourceResponse(
                            stream.get(), 200, L"OK", L"Content-Type: image/jpeg", &response));
                        CHECK_FAILURE(args->put_Response(response.get()));
                        return S_OK;
                    })
                    .Get(),
                &m_webResourceRequestedTokenForImageReplacing));
        }
        else
        {
            CHECK_FAILURE(m_webView->remove_WebResourceRequested(
                m_webResourceRequestedTokenForImageReplacing));
        }

get_BrowserVersionString

The browser version info of the current ICoreWebView2Environment, including channel name if it is not the WebView2 Runtime.

public HRESULT get_BrowserVersionString(LPWSTR * versionInfo)

It matches the format of the GetAvailableCoreWebView2BrowserVersionString API. Channel names are beta, dev, and canary.

The caller must free the returned string with CoTaskMemFree. See API Conventions.

        wil::unique_cotaskmem_string version_info;
        m_webViewEnvironment->get_BrowserVersionString(&version_info);
        MessageBox(
            m_mainWindow, version_info.get(), L"Browser Version Info After WebView Creation",
            MB_OK);

remove_NewBrowserVersionAvailable

Remove an event handler previously added with add_NewBrowserVersionAvailable.

public HRESULT remove_NewBrowserVersionAvailable(EventRegistrationToken token)