Android:在没有有效媒体播放器的情况下尝试调用getduration

Question

我使用下面的代码从URL (URL是完美的，没有重定向，404或任何东西)播放MP4视频(H.264, AAC编解码器)。然而，我不断得到错误"尝试调用getduration没有有效的mediaplayer"或ERROR/mediaplayer(382):错误(1，-2147483648)。有人知道怎么修理它吗?由于

 VideoView video = (VideoView) findViewById(R.id.myvideo);
 Intent videoint=getIntent();
 String url =  videoint.getStringExtra("url"); //The url pointing to the mp4
 video.setVideoPath(url);
 video.requestFocus();
 video.setMediaController(new MediaController(this));
 video.start();

Answer 1

从onPrepared回调中获取持续时间…这将确保在您尝试获取视频持续时间之前正确加载视频。

final VideoView video = (VideoView) findViewById(R.id.videoplayer);
            final MediaController controller = new MediaController(this);
            video.setVideoURI(Uri.parse(getIntent().getStringExtra("url")));
            video.setMediaController(controller);
            controller.setMediaPlayer(video);
            video.setOnPreparedListener(new OnPreparedListener() {
                   public void onPrepared(MediaPlayer mp) {
                       int duration = video.getDuration();
                       video.requestFocus();
                       video.start();
                       controller.show();
                   }
               });

Answer 2

确保在设置和准备好媒体播放器后设置所有与之交互的控件。例如:

            mediaPlayer.setDataSource(dataSource);
    mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
    mediaPlayer.setOnCompletionListener(this);
    mediaPlayer.prepare(); 
    progressBar = (ProgressBar) findViewById(R.id.progbar);
    progressBar.setVisibility(ProgressBar.VISIBLE);
            progressBar.setProgress(0);
            progressBar.setMax(mp.getDuration());
        mediaPlayer.start();

Answer 3

在我的情况下，问题是与搜索栏。在Service类中，我更改了:

@Override
public void onPrepared(MediaPlayer mp) {
    mp.start();}
public getDur() { return mediaPalyer.getDuration} 

int dr; //at the top inside Service class
@Override
public void onPrepared(MediaPlayer mp) {
    mp.start();
    dr = player.getDuration();}
public getDur() { return dr}