cefsharp执行javascript [英] cefsharp execute javascript

问题描述

我想在Windows窗体中使用 CefSharp 执行 JavaScript 代码，但它不起作用。代码如下，并且未显示消息 test 。我错过了什么吗？

I want to execute JavaScript code by using CefSharp in Windows Forms, but it does not work. The code is as following, and the message test is not shown. Did I miss something?

var browser = new ChromiumWebBrowser("http://localhost:50056/simple.aspx");
browser.Name = "Simple Page";
browser.Dock = DockStyle.Fill;            
this.Controls.Add(browser);
browser.ExecuteScriptAsync("alert('test');");

推荐答案

您必须等待浏览器充足执行JavaScript。开始尝试访问OnFrameLoadStart中的DOM很有诱惑力，而V8Context已经创建，您将能够执行DOM未完成加载的脚本。如果您需要尽可能早地访问DOM，那么订阅DOMContentLoaded，执行JavaScript的一些示例低于

You must wait for the browser to have sufficiently loaded before executing JavaScript. It's tempting to start trying to access the DOM in OnFrameLoadStart, whilst the V8Context will have been created and you will be able to execute a script the DOM will not have finished loading. If you need to access the DOM at it's earliest possible point then subscribe to DOMContentLoaded, some examples of executing JavaScript are below

browser.RenderProcessMessageHandler = new RenderProcessMessageHandler();

public class RenderProcessMessageHandler : IRenderProcessMessageHandler
{
  // Wait for the underlying JavaScript Context to be created. This is only called for the main frame.
  // If the page has no JavaScript, no context will be created.
  void IRenderProcessMessageHandler.OnContextCreated(IWebBrowser browserControl, IBrowser browser, IFrame frame)
  {
    const string script = "document.addEventListener('DOMContentLoaded', function(){ alert('DomLoaded'); });";

    frame.ExecuteJavaScriptAsync(script);
  }
}

//Wait for the page to finish loading (all resources will have been loaded, rendering is likely still happening)
browser.LoadingStateChanged += (sender, args) =>
{
  //Wait for the Page to finish loading
  if (args.IsLoading == false)
  {
    browser.ExecuteJavaScriptAsync("alert('All Resources Have Loaded');");
  }
}

//Wait for the MainFrame to finish loading
browser.FrameLoadEnd += (sender, args) =>
{
  //Wait for the MainFrame to finish loading
  if(args.Frame.IsMain)
  {
    args.Frame.ExecuteJavaScriptAsync("alert('MainFrame finished loading');");
  }
};

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