CoreWebView2.WebMessageReceived Event

Definition

Namespace:

Microsoft.Web.WebView2.Core

Assembly:

Microsoft.Web.WebView2.Core.dll

Package:

Microsoft.Web.WebView2 v1.0.2849.39

WebMessageReceived is raised when the IsWebMessageEnabled setting is set and the top-level document of the WebView runs window.chrome.webview.postMessage or window.chrome.webview.postMessageWithAdditionalObjects.

public event EventHandler<Microsoft.Web.WebView2.Core.CoreWebView2WebMessageReceivedEventArgs> WebMessageReceived;

member this.WebMessageReceived : EventHandler<Microsoft.Web.WebView2.Core.CoreWebView2WebMessageReceivedEventArgs> 

Public Custom Event WebMessageReceived As EventHandler(Of CoreWebView2WebMessageReceivedEventArgs) 

Event Type

EventHandler<CoreWebView2WebMessageReceivedEventArgs>

Remarks

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 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.