如何避免活动繁忙时从服务器开始播放视频的黑屏

Question

我正在打开一个按钮点击活动，下一个活动是从服务器播放视频，如果我点击按钮，它发生黑色，5-6秒后开始播放视频，如何避免黑屏?

下面是我的代码:

mPreview=new SurfaceView(getApplicationContext()); 
l1.addView(mPreview); 
holder = mPreview.getHolder(); 
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
extras = getIntent().getExtras(); 

以下内容为surfacected方法

        path = "http://www.pixintro.com/upload/video/Benetton.mp4";
        mMediaPlayer = new MediaPlayer();
        mMediaPlayer.setDataSource(Environment.getExternalStorageDirectory()+"/Benetton.mp4");
        mMediaPlayer.setDataSource(path);
        mMediaPlayer.setDisplay(holder);
        mMediaPlayer.prepare();
        mMediaPlayer.setOnBufferingUpdateListener(this);
        mMediaPlayer.setOnCompletionListener(this);
        mMediaPlayer.setOnPreparedListener(this);
        mMediaPlayer.setOnVideoSizeChangedListener(this);
        mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
public void onPrepared(MediaPlayer mediaplayer){
       mIsVideoReadyToBePlayed = true;
       if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown){
               holder.setFixedSize(mVideoWidth, mVideoHeight);
               mMediaPlayer.start();
       }
}

Answer 1

可以使用异步任务。当处理在doInBackground()中完成时，即在后台，您可以显示一个进度对话框(onPreExecute())，该对话框在任务完成后立即解散(onPostExecute)。

public class DisplayActivity extends Activity {
     @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_screen);
          // create surface view etc
              new Operation().execute();
}

}
 private class Operation extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... params) {
    // code to be executed in background thread 
    for(int i=0;i<5;i++) {
    try {
    Thread.sleep(1000);
    } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    }
    }
    return "Executed";
    } 
    @Override
    protected void onPostExecute(String result) {
    // runs on UI thread and updated UI after executing doInBackground
    progressDialog.dismiss();
    }
    @Override
    protected void onPreExecute() {
    ProgressDialog progressDialog = ProgressDialog.show(MainActivity.this, "Title ", "Loading...");
    progressDialog.show();
    }
    @Override
    protected void onProgressUpdate(Void... values) {
    // runs on UI thread and starts first
    }
    } 

Answer 2

看看这个界面。当媒体准备好播放时，它包含一个回调。

MediaPlayer也有一个prepareAsync方法。阅读这篇文章了解更多细节