Android开发之视频播放调用setVideoPath()方法

当setVideoPath()的时候，底层是这个走的：

setVideoPath()-->setVideoURI()-->openVideo()；

openVideo()只是setVideoURI()中的一部分，还有的没有写出来，下面看一下openVideo的具体内容：

 1 private void openVideo() {
 2         if (mUri == null || mSurfaceHolder == null) {
 3             // not ready for playback just yet, will try again later
 4             return;
 5         }
 6         // we shouldn‘t clear the target state, because somebody might have
 7         // called start() previously
 8         release(false);
 9
10         AudioManager am = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
11         am.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
12
13         try {
14             mMediaPlayer = new MediaPlayer();
15             // TODO: create SubtitleController in MediaPlayer, but we need
16             // a context for the subtitle renderers
17             final Context context = getContext();
18             final SubtitleController controller = new SubtitleController(
19                     context, mMediaPlayer.getMediaTimeProvider(), mMediaPlayer);
20             controller.registerRenderer(new WebVttRenderer(context));
21             controller.registerRenderer(new TtmlRenderer(context));
22             controller.registerRenderer(new Cea708CaptionRenderer(context));
23             controller.registerRenderer(new ClosedCaptionRenderer(context));
24             mMediaPlayer.setSubtitleAnchor(controller, this);
25
26             if (mAudioSession != 0) {
27                 mMediaPlayer.setAudioSessionId(mAudioSession);
28             } else {
29                 mAudioSession = mMediaPlayer.getAudioSessionId();
30             }
31             mMediaPlayer.setOnPreparedListener(mPreparedListener);
32             mMediaPlayer.setOnVideoSizeChangedListener(mSizeChangedListener);
33             mMediaPlayer.setOnCompletionListener(mCompletionListener);
34             mMediaPlayer.setOnErrorListener(mErrorListener);
35             mMediaPlayer.setOnInfoListener(mInfoListener);
36             mMediaPlayer.setOnBufferingUpdateListener(mBufferingUpdateListener);
37             mCurrentBufferPercentage = 0;
38             mMediaPlayer.setDataSource(mContext, mUri, mHeaders);
39             mMediaPlayer.setDisplay(mSurfaceHolder);
40             mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
41             mMediaPlayer.setScreenOnWhilePlaying(true);
42             mMediaPlayer.prepareAsync();
43
44             for (Pair<InputStream, MediaFormat> pending: mPendingSubtitleTracks) {
45                 try {
46                     mMediaPlayer.addSubtitleSource(pending.first, pending.second);
47                 } catch (IllegalStateException e) {
48                     mInfoListener.onInfo(
49                             mMediaPlayer, MediaPlayer.MEDIA_INFO_UNSUPPORTED_SUBTITLE, 0);
50                 }
51             }
52
53             // we don‘t set the target state here either, but preserve the
54             // target state that was there before.
55             mCurrentState = STATE_PREPARING;
56             attachMediaController();
57         } catch (IOException ex) {
58             Log.w(TAG, "Unable to open content: " + mUri, ex);
59             mCurrentState = STATE_ERROR;
60             mTargetState = STATE_ERROR;
61             mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);
62             return;
63         } catch (IllegalArgumentException ex) {
64             Log.w(TAG, "Unable to open content: " + mUri, ex);
65             mCurrentState = STATE_ERROR;
66             mTargetState = STATE_ERROR;
67             mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);
68             return;
69         } finally {
70             mPendingSubtitleTracks.clear();
71         }
72     }

从31行看，可以知道，执行setVideoPath()会重新执行VideoView的监听事件，会重新prepared等等。。。