当我尝试将显示设置为MediaPlayer时,表面已被释放

Question

我的xml文件:

<SurfaceView
    android:id="@+id/surfaceView"
    android:layout_marginTop="50dp"
    android:layout_width="fill_parent"
    android:layout_height="300dp" />

我的setDisplay功能:

public void playVideo() {
    MediaPlayer mp = new MediaPlayer();
    SurfaceView sv = (SurfaceView) this.findViewById(R.id.surfaceView);
    try {
        mp.setDataSource("sdcard/test/a.3gp");
        SurfaceHolder sh = sv.getHolder();
        mp.setDisplay(sh);***----the exception occured here***
        mp.prepare();
        mp.start();
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (SecurityException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

日志如下:

04-24 22:19:33.645: W/System.err(16106): java.lang.IllegalArgumentException: The surface has been released
04-24 22:19:33.645: W/System.err(16106):    at android.media.MediaPlayer._setVideoSurface(Native Method)
04-24 22:19:33.645: W/System.err(16106):    at android.media.MediaPlayer.setDisplay(MediaPlayer.java:698)

我在这里发现了一些类似的问题,但所有这些都不适合我.等待你的答案.非常感谢.

Answer 1

表面可以被破坏.这就是为什么你需要public void surfaceDestroyed(SurfaceHolder holder)像这样添加到SurfaceView的实现:

  @Override
public void surfaceDestroyed(SurfaceHolder holder) {
    synchronized (this) {
        hasActiveHolder = false;

        synchronized(this)          {
              this.notifyAll(); 
        }
    } 
}

您还应该添加一个处理Surface创建的函数:

@Override
public void surfaceCreated(SurfaceHolder holder) {
     synchronized (this) {
        hasActiveHolder = true;
        this.notifyAll()
     }
}

并以这种方式修改自己的功能:

    mp.setDataSource("sdcard/test/a.3gp");
    SurfaceHolder sh = sv.getHolder();
    synchronized (this) {
       while (!hasActiveHolder) {
              try {
                  this.wait();
              } catch (InterruptedException e) {
                //Print something
              }
        }
        mp.setDisplay(sh);
        mp.prepare();
    }

您有另一种选择,就像Google建议您使用SurfaceView一样:在一个单独的线程中.

Answer 2

这是与执行顺序相关的事情,因为必须在设置显示之前首先创建表面MediaPlayer,因此您必须将回调方法覆盖surfaceCreated到以下内容:

@Override
public void surfaceCreated(SurfaceHolder holder) {
    mp.setDisplay(sh); // now "mp" is defined as a class variable
}

现在你的play方法中没有setDisplay:

private MediaPlayer mp; // to use it inside surfaceCreated callback method
public void playVideo() {
    mp = new MediaPlayer();
    SurfaceView sv = (SurfaceView) this.findViewById(R.id.surfaceView);
    try {
        mp.setDataSource("sdcard/test/a.3gp");
        SurfaceHolder sh = sv.getHolder();
        mp.prepare();
        mp.start();
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (SecurityException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Answer 3

使用 SurfaceHolder.Callback 如下

SurfaceView mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
SurfaceHolder holder = mSurfaceView.getHolder();
final MediaPlayer player = new MediaPlayer();

holder.addCallback(new SurfaceHolder.Callback() {
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        player.setDisplay(holder);
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, 
    int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {

    }
});

String UrlPath="android.resource://"+getActivity().getPackageName()+"/"+R.raw.your_file_name_without_extension;
try {
    player.setDataSource(getActivity(),Uri.parse(UrlPath));
    player.prepareAsync();
} catch (IOException e) {
    e.printStackTrace();
}
player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {

    @Override
    public void onPrepared(MediaPlayer mp) {
        mp.start();
    }
});