我在片段中创建了一个ExoPlayer。如果在播放期间我按下主页按钮，然后返回播放器，播放器似乎为空，播放/暂停按钮不再起作用。视频消失了。视频播放器视图似乎完全是空的。
public class PlaybackFragment extends Fragment implements View.OnClickListener, EventListener, PlaybackControlView.VisibilityListener {
private static final String TAG = PlaybackFragment.class.getSimpleName();
Video mVideo; //Video object passed in for playback
SimpleExoPlayerView mExoPlayerView;
private TextView mVideoTitle;
private SimpleExoPlayer mExoPlayer;
private FrameLayout mFullScreenButton; //Holds the fullscreen icon
private Dialog mFullScreenDialog;
private ImageView mFullScreenIcon;
private boolean mExoPlayerFullScreen; //full-screen dialog
private static final String LOG_TAG = PlaybackFragment.class.getSimpleName();
/**
* Root ViewGroup holding the fragment
*/
private ViewGroup mPlayerViewContainer;
/**
* Context used across the class
*/
private Context mContext;
/**
* Activity to which the fragment is added
*/
private Activity mActivity;
/**
* Uri received from calling activity containing Uri to the video to be played
*/
private Uri mUri;
public PlaybackFragment() {
super();
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
Log.d(TAG, "onCreate: ");
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
Log.d(TAG, "onCreateView: ");
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.fragment_playback, container, false);
mVideoTitle = root.findViewById(R.id.playback_video_title);
mExoPlayerView = root.findViewById(R.id.exoPlayerView);
mPlayerViewContainer = (ViewGroup) mExoPlayerView.getParent();
return root;
}
/**
* Sets the Uri to video to be played
* @param mediaUri
*/
public void playUri(Uri mediaUri) {
mUri = mediaUri;
}
@Override
public void onViewStateRestored(@Nullable Bundle savedInstanceState) {
Log.d(TAG, "onViewStateRestored: ");
super.onViewStateRestored(savedInstanceState);
}
private void preparePlayback() {
mExoPlayerView.setControllerVisibilityListener(this);
mExoPlayerView.requestFocus();
BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
TrackSelection.Factory trackSelectionFactory = new AdaptiveTrackSelection.Factory(bandwidthMeter);
TrackSelector trackSelector =
new DefaultTrackSelector(trackSelectionFactory);
mExoPlayer =
ExoPlayerFactory.newSimpleInstance(getContext(), trackSelector);
mExoPlayerView.setPlayer(mExoPlayer);
DataSource.Factory dsFactory = new DefaultDataSourceFactory(mContext,
com.google.android.exoplayer2.util.Util.getUserAgent(mContext, mActivity.getApplicationInfo().processName), null);
// Produces Extractor instances for parsing the media data.
ExtractorsFactory extractorsFactory = new DefaultExtractorsFactory();
MediaSource videoSource = new ExtractorMediaSource(mUri,
dsFactory, extractorsFactory, null, null);
// Prepare the player with the source.
mExoPlayer.prepare(videoSource);
//start player
mExoPlayer.setPlayWhenReady(true);
mExoPlayer.addListener(this);
// initFullscreenDialog();
initFullscreenButton();
}
@Override
public void onVisibilityChange(int visibility) {
}
@Override
public void onTimelineChanged(Timeline timeline, Object manifest) {
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
Log.d(TAG, "onActivityCreated: ");
super.onActivityCreated(savedInstanceState);
mContext = mActivity = getActivity();
preparePlayback();
}
@Override
public void onStart() {
super.onStart();
Log.d(TAG, "onStart: ");
}
@Override
public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
}
@Override
public void onLoadingChanged(boolean isLoading) {
}
@Override
public void onClick(View v) {
}
public void pause() {
mExoPlayer.stop();
}
//Interface to trigger playback-finish event in the parent activity
public interface OnPlayStateListener {
void onPlayFinish();
}
OnPlayStateListener mCallback;
@Override
public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
if(playbackState == Player.STATE_ENDED) {
quitFullScreen(); //Leave fullscreen after playback finished
mCallback.onPlayFinish();
Log.i(LOG_TAG,"onPlayFinish() triggered");
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
try {
mCallback = (OnPlayStateListener) context;
} catch (ClassCastException e){
throw new ClassCastException(context.toString() + " must implement OnPlayStateListener");
}
}
@Override
public void onRepeatModeChanged(int repeatMode) {
}
@Override
public void onShuffleModeEnabledChanged(boolean shuffleModeEnabled) {
}
@Override
public void onPlayerError(ExoPlaybackException error) {
Toast.makeText(mContext,error.getLocalizedMessage(),Toast.LENGTH_SHORT).show();
}
@Override
public void onPositionDiscontinuity(int reason) {
}
@Override
public void onPlaybackParametersChanged(PlaybackParameters playbackParameters) {
}
@Override
public void onSeekProcessed() {
}
private void goFullScreen() {
Util.showFullScreen(mActivity, mExoPlayerView);
// ((ViewGroup) mExoPlayerView.getParent()).removeView(mExoPlayerView);
// mFullScreenDialog.addContentView(mExoPlayerView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
mFullScreenIcon.setImageDrawable(ContextCompat.getDrawable(mContext, R.drawable.ic_fullscreen_exit));
mExoPlayerFullScreen = true;
// mFullScreenDialog.show();
}
private void quitFullScreen() {
Util.quitFullScreen(mActivity, mPlayerViewContainer, mExoPlayerView);
// ((ViewGroup) mExoPlayerView.getParent()).removeView(mExoPlayerView);
// FrameLayout frame = mActivity.findViewById(R.id.main_media_frame);
// frame.addView(mExoPlayerView);
mExoPlayerFullScreen = false;
// mFullScreenDialog.dismiss();
mFullScreenIcon.setImageDrawable(ContextCompat.getDrawable(mContext, R.drawable.ic_fullscreen_expand));
}
private void initFullscreenButton() {
PlaybackControlView controlView = mExoPlayerView.findViewById(R.id.exo_controller);
mFullScreenIcon = controlView.findViewById(R.id.exo_fullscreen_icon);
mFullScreenButton = controlView.findViewById(R.id.exo_fullscreen_button);
mFullScreenButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!mExoPlayerFullScreen) {
goFullScreen();
}
else {
quitFullScreen();
}
}
});
}
private void initFullscreenDialog() {
//The following uses anonymous class to create a custom dialog
mFullScreenDialog = new Dialog(mContext, android.R.style.Theme_DeviceDefault_NoActionBar_Fullscreen) {
@Override
public void onBackPressed() {
if(mExoPlayerFullScreen) {
quitFullScreen();
}
super.onBackPressed();
}
};
}
@Override
public void onDestroy() {
super.onDestroy();
if(mExoPlayer != null) mExoPlayer.release();
Log.d(TAG, "onDestroy: ");
}
/**
* Moves forward or backward by step milliseconds <br/>
* @param step specifies step size. It is a positive or negative integer for moving forward and
* backward, respectively.
*/
public void movePlayPos(int step) {
mExoPlayer.seekTo(mExoPlayer.getCurrentPosition() + step);
}
@Override
public void onSaveInstanceState(@NonNull Bundle outState) {
Log.d(TAG, "onSaveInstanceState: ");
super.onSaveInstanceState(outState);
outState.putLong("position", mExoPlayer.getCurrentPosition());
}
}
我已经检查过Logcat中的片段生命周期，但似乎在我回到播放器活动后，只调用片段的onStart()。所以，没有办法恢复状态。任何想法如何在暂停时保存视频播放位置并在活动的onResume上恢复播放？
答案 0 :(得分：1)
您可以在exPause（）中保存exoplayer的当前位置，然后在onResume（）中搜索该位置。 试试这个：
long position;
@Override
protected void onPause() {
super.onPause();
if(mExoPlayerView != null && mExoPlayerView.getPlayWhenReady()) {
position = mExoPlayerView.getCurrentPosition();
mExoPlayerView.setPlayWhenReady(false);
}
}
@Override
protected void onResume() {
super.onResume();
if(mExoPlayerView != null) {
mExoPlayerView.seekTo(position);
mExoPlayerView.setPlayWhenReady(true);
}
}