c# - 为什么这个简单的Mobile Form在使用播放器时没有关闭

Question

我创建了这个带有关闭按钮的简单示例表单。

当不使用 Interop.WMPLib.dll 时，一切都按预期工作

我已经看到其他应用程序使用它没有问题，但为什么当我只添加以下行时 Form 进程没有关闭:

SoundPlayer myPlayer = new SoundPlayer();

当然还有处置它:

if (myPlayer != null)
            {
                myPlayer.Dispose();
                myPlayer = null;
            }

窗体关闭但调试器 VS2008 仍处于事件状态。 Form 项目和 dll 仍处于事件状态。

如果您给我发送电子邮件至 xdasleepsense@gmail.com，我可以将压缩的项目发送给您。

下面是 dll 的类:

使用系统；使用 System.Collections.Generic；使用系统文本；使用系统线程；使用 System.Runtime.InteropServices；使用 WMPLib；

命名空间 WindowsMo​​bile.Utilities{ public delegate void SoundPlayerStateChanged(SoundPlayer sender, SoundPlayerState newState);

public enum SoundPlayerState
{
    Stopped,
    Playing,
    Paused,
}


public class SoundPlayer : IDisposable
{
    [DllImport("coredll")]
    public extern static int waveOutSetVolume(int hwo, uint dwVolume);

    [DllImport("coredll")]
    public extern static int waveOutGetVolume(int hwo, out uint dwVolume);

    WindowsMediaPlayer myPlayer = new WindowsMediaPlayer();

    public SoundPlayer()
    {
        myPlayer.uiMode = "invisible";
        myPlayer.settings.volume = 100;
    }

    string mySoundLocation = string.Empty;

    public string SoundLocation
    {
        get { return mySoundLocation; }
        set { mySoundLocation = value; }
    }

    public void Pause()
    {
        myPlayer.controls.pause();
    }

    public void PlayLooping()
    {
        Stop();
        myPlayer.URL = mySoundLocation;
        myPlayer.settings.setMode("loop", true);
    }

    public int Volume
    {
        get { return myPlayer.settings.volume; }
        set { myPlayer.settings.volume = value; }
    }

    public void Play()
    {
        Stop();
        myPlayer.URL = mySoundLocation;
        myPlayer.controls.play();
    }

    public void Stop()
    {
        myPlayer.controls.stop();
        myPlayer.close();
    }

    #region IDisposable Members

    public void Dispose()
    {
        try
        {
            Stop();
        }
        catch (Exception)
        {
        }
        // need this otherwise the process won't exit?!
        try
        {
            int ret = Marshal.FinalReleaseComObject(myPlayer);
        }
        catch (Exception)
        {
        }
        myPlayer = null;
        GC.Collect();
    }

    #endregion
}
}

Answer 1

A MessageBox 或 Below 解决了它。谢谢。

public void Dispose()
    {
        try
        {
            Stop();
        }
        catch (Exception)
        {
        }
        // need this otherwise the process won't exit?!
        try
        {
            int ret = Marshal.FinalReleaseComObject(myPlayer);
        }
        catch (Exception)
        {
        }
        myPlayer = null;
        GC.Collect();

        //If you don't do this, it will not quit
        //http://www.eggheadcafe.com/software/aspnet/31363254/media-player-freezing-app.aspx
        for (int s = 0; s < 100; s++)
        {
            Application.DoEvents();
            Thread.Sleep(1);
        }
        GC.WaitForPendingFinalizers();

        //MessageBox.Show("Application Exiting");
    }