Question

我一直试图让WebBrowser在XNA 4.0中绘制一个纹理，我找到了几个如何做的指南。问题是当我尝试实现它时，无论是更改Url属性还是调用Navigate()它都不会加载页面。我有一种感觉，我对所需的线程有点无知，因为我的项目不是作为STA线程启动的，所以我创建了一个单独的线程来启动Web浏览器并渲染到位图。

以下是我的启动方式：

public void LoadTexture(GraphicsDevice gfx, ContentManager content, string filename, float duration = -1f)
{
    this.gfx = gfx;
    this.filename = filename;
    this.duration = duration;

    _resetEvent = new AutoResetEvent(false);
    Thread thread = new Thread(GetWebScreenshot);
    thread.SetApartmentState(ApartmentState.STA);
    thread.Start();
    _resetEvent.WaitOne();
}

这里是GetWebScreenshot：

public void GetWebScreenshot()
{
    this.web = new WebBrowser();
    this.web.Size = new Size(gfx.Viewport.Width, gfx.Viewport.Height);
    this.web.Url = new Uri(this.filename);

    while (this.web.ReadyState != WebBrowserReadyState.Complete)
    {
        if (this.web.ReadyState != WebBrowserReadyState.Uninitialized)
        {
            Console.WriteLine(this.web.ReadyState.ToString());
        }
    }

    bitmap = new Bitmap(this.gfx.Viewport.Width, this.gfx.Viewport.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
    this.web.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height));
    this.texture = BitmapToTexture2D(this.gfx, bitmap);
    _resetEvent.Set();
}

ReadyState属性永远不会从Uninitialized更改，我也尝试使用DocumentReady事件，并且永远不会被解雇。我也尝试过Join()而不是AutoResetEvent，但似乎没有任何效果。

Answer 1

我是对的，这是我的无知。 ActiveX控件和Single Threaded Apartments的关键是需要抽取消息队列。所以现在我将我的代码重组为以下内容：

public void LoadTexture(GraphicsDevice gfx, ContentManager content, string filename, float duration = -1f)
{
    this.gfx = gfx;
    this.filename = filename;
    this.duration = duration;

    Thread thread = new Thread(GetWebScreenshot);
    thread.SetApartmentState(ApartmentState.STA);
    thread.Start();
    thread.Join();
}

public void GetWebScreenshot()
{
    this.web = new WebBrowser();
    this.web.Size = new Size(gfx.Viewport.Width, gfx.Viewport.Height);
    this.web.Url = new Uri(this.filename);
    this.web.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(web_DocumentCompleted);
    Application.Run(); // Starts pumping the message queue (and keeps the thread running)
}

void web_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
    Bitmap bitmap = new Bitmap(this.gfx.Viewport.Width, this.gfx.Viewport.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
    this.web.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height));
    this.texture = HTMLTextureFactoryMachine.BitmapToTexture2D(this.gfx, bitmap);
    Application.ExitThread(); // Exits the thread
}

这没问题。

XNA 4.0中的WebBrowser不能导航

1 个答案: