android 編寫簡易視頻播放器

public class VideoActivity extends Activity {
private static final String TAG = "VideoActivity";
private EditText filenameText;
private SurfaceView surfaceView;
private MediaPlayer mediaPlayer;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  ButtonClickListener listener = new ButtonClickListener();
  ImageButton playButton = (ImageButton) this.findViewById(R.id.play);
  playButton.setOnClickListener(listener);
  ImageButton pauseButton = (ImageButton) this.findViewById(R.id.pause);
  pauseButton.setOnClickListener(listener);
  ImageButton resetButton = (ImageButton) this.findViewById(R.id.reset);
  resetButton.setOnClickListener(listener);
  ImageButton stopButton = (ImageButton) this.findViewById(R.id.stop);
  stopButton.setOnClickListener(listener);
// 重點 這個地方需要設定回呼函數  繼承Callback 類實現三個方法
  surfaceView.getHolder().addCallback(new myCallback());
  filenameText = (EditText) this.findViewById(R.id.filename);
  surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
  surfaceView.getHolder() .setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// 設定這個大小
  surfaceView.getHolder().setFixedSize(176, 144);
  mediaPlayer = new MediaPlayer();
}
private class myCallback implements android.view.SurfaceHolder.Callback {
  @Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
  }
  @Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
  }
  @Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
  }
}
// 當來電話的時候需要停掉播放業務
@Override
protected void onPause() {
if (mediaPlayer.isPlaying())
   mediaPlayer.pause();
super.onPause();
}
@Override
protected void onResume() {
if (mediaPlayer.isPlaying())
   mediaPlayer.pause();
super.onResume();
}
@Override
protected void onDestroy() {
if (mediaPlayer.isPlaying())
   mediaPlayer.stop();
// 注意這個地方是釋放
  mediaPlayer.release();
super.onStop();
}
private class ButtonClickListener implements View.OnClickListener {
  @Override
public void onClick(View v) {
try {
    String filename = filenameText.getText().toString();
switch (v.getId()) {
case R.id.play:
// 得到檔案名稱 重點代碼
     String filenames = filenameText.getText().toString();
// 第一步對給對象進行重設
     mediaPlayer.reset();
// 設定流的類型 關鍵代碼
     mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
// 設定資料來源
     mediaPlayer.setDataSource("/sdcard/" + filenames); // 設定需要播放的視頻
// 把視頻輸出到顯示控制項上 重點代碼
     mediaPlayer.setDisplay(surfaceView.getHolder());
// 播放時前需要緩衝一下
     mediaPlayer.prepare();
     mediaPlayer.start();
break;
case R.id.pause:
if (mediaPlayer.isPlaying()) {
      mediaPlayer.pause();
     } else {
      mediaPlayer.start();
     }
break;
case R.id.reset:
if (!mediaPlayer.isPlaying()) {
      mediaPlayer.start();
     }
// 跳回到起始的地方重新播放
     mediaPlayer.seekTo(0);
break;
case R.id.stop:
if (mediaPlayer.isPlaying()) {
      mediaPlayer.stop();
     }
break;
    }
   } catch (Exception e) {
    Log.e(TAG, e.toString());
   }
  }
}
}