interface ICoreWebView2WebMessageReceivedEventArgs

Note

This reference is no longer being maintained. For the latest API reference, see WebView2 API Reference.

interface ICoreWebView2WebMessageReceivedEventArgs
  : public IUnknown

Event args for the WebMessageReceived event.

Summary

Members	Descriptions
get_Source	The URI of the document that sent this web message.
get_WebMessageAsJson	The message posted from the WebView content to the host converted to a JSON string.
TryGetWebMessageAsString	If the message posted from the WebView content to the host is a string type, this method returns the value of that string.

Applies to

Product	Introduced
WebView2 Win32	0.9.430
WebView2 Win32 Prerelease	0.9.488

Members

get_Source

The URI of the document that sent this web message.

public HRESULT get_Source(LPWSTR * source)

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

get_WebMessageAsJson

The message posted from the WebView content to the host converted to a JSON string.

public HRESULT get_WebMessageAsJson(LPWSTR * webMessageAsJson)

Run this operation to communicate using JavaScript objects.

For example, the following postMessage runs result in the following WebMessageAsJson values.

postMessage({'a': 'b'})      L"{\"a\": \"b\"}"
postMessage(1.2)             L"1.2"
postMessage('example')       L"\"example\""

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

TryGetWebMessageAsString

If the message posted from the WebView content to the host is a string type, this method returns the value of that string.

public HRESULT TryGetWebMessageAsString(LPWSTR * webMessageAsString)

If the message posted is some other kind of JavaScript type this method fails with the following error.

E_INVALIDARG

Run this operation to communicate using simple strings.

For example, the following postMessage runs result in the following WebMessageAsString values.

postMessage({'a': 'b'})      E_INVALIDARG
postMessage(1.2)             E_INVALIDARG
postMessage('example')       L"example"

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