entityMap|blocks|key|1fp6o|text|您可以尝试将代码中的Task.Run替换为下面的自定义TaskRunSTA方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data^0|A|8|R|A^^$0|$]|1|@$2|3|4|5|6|7|8|G|9|@$A|H|B|I|C|D]|$A|J|B|K|C|D]]|E|@]|F|$]]]]

You could try replacing the <code>Task.Run</code> in your code with the custom <code>TaskRunSTA</code> method below:
<pre><code>public static Task TaskRunSTA(Func&lt;Task&gt; action)
{
 var tcs = new TaskCompletionSource&lt;object&gt;(
 TaskCreationOptions.RunContinuationsAsynchronously);
 var thread = new Thread(() =&gt;
 {
 Application.Idle += Application_Idle;
 Application.Run();
 });
 thread.SetApartmentState(ApartmentState.STA);
 thread.Start();
 return tcs.Task;

 async void Application_Idle(object sender, EventArgs e)
 {
 Application.Idle -= Application_Idle;
 try
 {
 await action();
 tcs.SetResult(null);
 }
 catch (Exception ex) { tcs.SetException(ex); }
 Application.ExitThread();
 }
}
</code></pre>
This method starts a new STA thread, and runs a dedicated application message loop inside this thread. The asynchronous delegate that you pass as argument will run on this message loop, with the appropriate synchronization context installed. As long as your asynchronous delegate does not contain any <code>await</code> configured with <code>.ConfigureAwait(false)</code>, all your code, including the events raised by the <code>WebView2</code> component, should run on this thread.
<hr />
Note: TBH I don't know if handling the first occurrence of the <a href="https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.application.idle" rel="nofollow noreferrer"><code>Application.Idle</code></a> event is the best way to embed custom code in a message loop, but it seems to work quite well. It is worth noting that this event is attached and detached from an internal class <code>ThreadContext</code> (<a href="https://referencesource.microsoft.com/system.windows.forms/winforms/managed/system/winforms/Application.cs.html#2cc1839377435079" rel="nofollow noreferrer">source code</a>), and this class has a dedicated instance per thread. So each thread receives the <code>Idle</code> events that are associated with the message loop running on that thread. In other words there is no risk of receiving an event that is originated from some other unrelated message loop, that runs concurrently on another thread.

I have simple default Windows desktop form <code>Form1</code> with one button <code>btn_Go</code> as a test. 
I want to run multiple parallel WebView2 instances and process html code from rendered page.
To run WebView2 in parallel I use SemaphoreSlim (set to parallel 2). Another SemaphoreSlim is used for wait until WebView2 render the document (with some time delay).
But my code falls on <code>await webBrowser.EnsureCoreWebView2Async();</code>. Inner exception from debuger in <code>WebView2</code> instance <code>webBrowser</code> is:
<code>{&quot;Cannot change thread mode after it is set. (Exception from HRESULT: 0x80010106 (RPC_E_CHANGED_MODE))&quot;} System.Exception {System.Runtime.InteropServices.COMException}</code>
How can I call WebView2 multiple times in parallel and process all urls?
Full demo code:
<pre class="lang-cs prettyprint-override"><code>using Microsoft.Web.WebView2.WinForms;
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WebView2Test
{
 public partial class Form1 : Form
 {
 public Form1() { InitializeComponent(); }

 private void btn_Go_Click(object sender, EventArgs e) { Start(); }

 private async void Start()
 {
 var urls = new List&lt;string&gt;() { &quot;https://www.google.com/search?q=test1&quot;, &quot;https://www.google.com/search?q=test2&quot;, &quot;https://www.google.com/search?q=test3&quot; };
 var tasks = new List&lt;Task&gt;();
 var semaphoreSlim = new SemaphoreSlim(2);
 foreach (var url in urls)
 {
 await semaphoreSlim.WaitAsync();
 tasks.Add(
 Task.Run(async () =&gt; {
 try { await StartBrowser(url); }
 finally { semaphoreSlim.Release(); }
 }));
 }
 await Task.WhenAll(tasks);
 }

 public async Task&lt;bool&gt; StartBrowser(string url)
 {
 SemaphoreSlim semaphore = new System.Threading.SemaphoreSlim(0, 1);

 System.Timers.Timer wait = new System.Timers.Timer();
 wait.Interval = 500;
 wait.Elapsed += (s, e) =&gt;
 {
 semaphore.Release();
 };
 WebView2 webBrowser = new WebView2();
 webBrowser.NavigationCompleted += (s, e) =&gt;
 {
 if (wait.Enabled) { wait.Stop(); }
 wait.Start();
 };
 await webBrowser.EnsureCoreWebView2Async();
 webBrowser.CoreWebView2.Navigate(url);

 await semaphore.WaitAsync();
 if (wait.Enabled) { wait.Stop(); }

 var html = await webBrowser.CoreWebView2.ExecuteScriptAsync(&quot;document.documentElement.outerHTML&quot;);
 return html.Length &gt; 10;
 }
 }
}
</code></pre>
I have <a href="https://docs.microsoft.com/en-us/microsoft-edge/webview2/gettingstarted/winforms#prerequisites" rel="nofollow noreferrer">WebView2 runtime</a> installed.
-- Tests
Prepare <code>WebView2</code> in main thread and send it into child threads.
I have already tried to create list of <code>WebView2</code> in <code>Start</code> method from main Thread <code>var bro = new List&lt;WebView2&gt;() { new WebView2(), new WebView2(), new WebView2() };</code> and send WebView2 instance into <code>await StartBrowser(bro[index], url);</code> ... but this ends with the same error.

Parallel using of WebView2 in async Task

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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 我有一个简单的默认窗口桌面表单Form1的一个按钮btn_Go作为测试。 我想运行多个并行的WebView2实例，并处理渲染页面中的html代码。为了并行运行WebView2，我使用了SemaphoreSlim (设置为parallel 2)。另一个SemaphoreSlim用于等待WebView2呈现文档(有一些时间延迟)。 但是我的代码落在了await webBrowser.EnsureCo

问异步任务中WebView2的并行使用
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