如果控制程序创建的Windows Media Player视频是黑色的 [英] Windows Media Player video is black if control is created programmatically

问题描述

我试图以编程方式创建Windows Media Player控件这样我就可以捕获任何初始化错误。当我干脆放弃我的窗体上的控件之前，一切都发挥很好。但现在，我想以编程方式玩的东西，视频没有显示在控制。我只看到黑色的视频，但我听到声音。

任何想法？

 公共TrimVideoControl（）
 {
的InitializeComponent（）; 
 
 //尝试创建WMP控制
 //我们这样做是在这里，所以我们可以优雅地捕捉错误如果控制不加载
试
 {
 
 wmPlayer =新AxWMPLib.AxWindowsMediaPlayer（）; 
（（System.ComponentModel.ISupportInitialize）（wmPlayer））BeginInit在（）; 
 // SuspendLayout（）; 
 wmPlayer.CreateControl（）; 
 wmPlayer.Name =wmPlayer; 
 wmPlayer.Ctlenabled = TRUE; 
 System.ComponentModel.ComponentResourceManager资源=新System.ComponentModel.ComponentResourceManager（typeof运算（TrimVideoControl））; 
 wmPlayer.OcxState =（（System.Windows.Forms.AxHost.State）（resources.GetObject（wmPlayer.OcxState）））; 
 wmPlayer.Location =新点（12，13）; 
 wmPlayer.Size =新的大小（636，358）; 
 wmPlayer.enableContextMenu = TRUE; 
 wmPlayer.stretchToFit = TRUE; 
 wmPlayer.uiMode =无; 
 wmPlayer.settings.autoStart = FALSE; 
 wmPlayer.ErrorEvent + = wmPlayer_ErrorEvent; 
 wmPlayer.MediaChange + = wmPlayer_MediaChange; 
 wmPlayer.MediaError + = wmPlayer_MediaError; 
 wmPlayer.OpenStateChange + = wmPlayer_OpenStateChange; 
 wmPlayer.PlayStateChange + = wmPlayer_PlayStateChange; 
 wmPlayer.Warning + = wmPlayer_Warning; 
 this.Controls.Add（wmPlayer）; 
（（System.ComponentModel.ISupportInitialize）（wmPlayer））EndInit在（）; 
 
 //this.ResumeLayout(false）; 
 //this.PerformLayout（）; 
 //wmPlayer.Show（）; 
 //wmPlayer.BringToFront（）; 
} 
赶上（异常前）
 {
 Logger.Error（错误创建WMP的控制：+ EX）; 
} 
 
 
} 
  

解决方案

与MediaPalyer在运行时创建的具体问题是，我们不能执行MediaPlayer的状态的组件之前，任何更改（如URL / uimode等任何设置）已完全初始化的事实。该VS设计师系列化组件作为 AxHost.State 对象状态，不影响任何其他设置。在运行时，你可以用下面的办法：

 无效AddMediaPlayer（字符串URL）{
尝试{
 VAR wmPlayer =新AxWMPLib.AxWindowsMediaPlayer（）; 
 
（（System.ComponentModel.ISupportInitialize）（wmPlayer））BeginInit在（）; 
 wmPlayer.Name =wmPlayer; 
 wmPlayer.Enabled = TRUE; 
 wmPlayer.Dock = System.Windows.Forms.DockStyle.Fill; 
 this.Controls.Add（wmPlayer）; 
（（System.ComponentModel.ISupportInitialize）（wmPlayer））EndInit在（）; 
 
 //初始化后，您可以自定义媒体播放器
 wmPlayer.uiMode =无; 
 wmPlayer.URL =网址; 
} 
赶上{} 
} 
  

I'm trying to programmatically create the Windows Media Player control so I can trap any initialization errors. Before when I simply dropped the control on my form, everything played fine. But now that I'm trying to play things programmatically, the video isn't appearing in the control. I only see black video but I hear the audio.

Any ideas?

    public TrimVideoControl()
    {
        InitializeComponent();

        // Try creating WMP control
        // We do this here so we can gracefully catch errors if the control doesn't load
        try
        {

            wmPlayer = new AxWMPLib.AxWindowsMediaPlayer();
            ((System.ComponentModel.ISupportInitialize)(wmPlayer)).BeginInit();
            //SuspendLayout();
            wmPlayer.CreateControl();
            wmPlayer.Name = "wmPlayer";
            wmPlayer.Ctlenabled = true;
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(TrimVideoControl));
            wmPlayer.OcxState = ((System.Windows.Forms.AxHost.State)(resources.GetObject("wmPlayer.OcxState")));
            wmPlayer.Location = new Point(12, 13);
            wmPlayer.Size = new Size(636, 358);
            wmPlayer.enableContextMenu = true;
            wmPlayer.stretchToFit = true;
            wmPlayer.uiMode = "none";
            wmPlayer.settings.autoStart = false;
            wmPlayer.ErrorEvent += wmPlayer_ErrorEvent;
            wmPlayer.MediaChange += wmPlayer_MediaChange;
            wmPlayer.MediaError += wmPlayer_MediaError;
            wmPlayer.OpenStateChange += wmPlayer_OpenStateChange;
            wmPlayer.PlayStateChange += wmPlayer_PlayStateChange;
            wmPlayer.Warning += wmPlayer_Warning;
            this.Controls.Add(wmPlayer);
            ((System.ComponentModel.ISupportInitialize)(wmPlayer)).EndInit();

            //this.ResumeLayout(false);
            //this.PerformLayout(); 
            //wmPlayer.Show();
            //wmPlayer.BringToFront();
        }
        catch (Exception ex)
        {
            Logger.Error("Error creating WMP control: " + ex);
        }


    }

解决方案

The exact problem with the MediaPalyer runtime creation is the fact that we can't perform any changes of MediaPlayer's state (any settings like url/uimode etc.) before the component have been completely initialized. The VS-designer serialized component's state as an AxHost.State object and don't affect any other settings. At runtime you can use the following approach:

void AddMediaPlayer(string url) {
    try {
        var wmPlayer = new AxWMPLib.AxWindowsMediaPlayer();

        ((System.ComponentModel.ISupportInitialize)(wmPlayer)).BeginInit();
        wmPlayer.Name = "wmPlayer";
        wmPlayer.Enabled = true;
        wmPlayer.Dock = System.Windows.Forms.DockStyle.Fill;
        this.Controls.Add(wmPlayer);
        ((System.ComponentModel.ISupportInitialize)(wmPlayer)).EndInit();

        // After initialization you can customize the Media Player
        wmPlayer.uiMode = "none";
        wmPlayer.URL = url;
    }
    catch { }
}

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