android片段过渡动画显示黑屏

Question

我在获取片段（SimpleExoPlayerView）过渡动画以便fadein和fadeout正常工作时遇到问题。在过渡期间，如果我将持续时间设置为5秒，我将看到5秒的黑屏。奇怪的是，过渡动画适用于其他动画类型，例如水平滑入和滑出。我只是无法弄清楚我的编码有什么问题，希望有人可以提供帮助....下面是代码

/res/animator/fade_in.xml

<?xml version="1.0" encoding="utf-8" ?>
<objectAnimator 
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:valueFrom="0.0"
        android:valueTo="1.0"
        android:valueType="floatType"
        android:propertyName="alpha"
        android:duration="5000" />

/res/animator/fade_out.xml     ================================================== =================          

MainActivity中的代码

VideoFragment videoFragment = new VideoFragment();          
videoFragment.setArguments(bundle);         fm = getFragmentManager();          
ft = fm.beginTransaction();                     
ft.setCustomAnimations(R.animator.fade_in, R.animator.fade_out);                     ft.replace(R.id.fragment_place, videoFragment);            
ft.addToBackStack(null);            
ft.commit();

videoFragment中的代码

public class VideoFragment extends Fragment {                   
    private final String TAG = "Video Fragment";            
    private Uri videoUri;           
    private String filePath;            
    private String filename;            
    private Integer duration;           
    private Integer currentIndex;           
    private Context mContext;                   
    private SimpleExoPlayerView playerView;         
    private SimpleExoPlayer videoPlayer;            
    private long playbackPosition;          
    private int currentWindow;          
    private boolean playWhenReady = true;                   
    private View v;    

    public VideoFragment() {                
        // Required empty public constructor
    }            

    @Override    
    public void onStart() {   
        super.onStart();                
        initializePlayer();     
    }                  

    @Override          
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
        v = inflater.inflate(R.layout.fragment_video, container, false);           
        playerView = (SimpleExoPlayerView) v.findViewById(R.id.video_view);    
        mContext = container.getContext();          
        filePath = getArguments().getString("filepath");      
        filename = getArguments().getString("filename");            
        duration = getArguments().getInt("duration");           
        currentIndex = getArguments().getInt("currentIndex");   
        return  v;  
    }       
    //===============================================================================     
    // Initialize Player     
    //============================================================================= 
    private void initializePlayer() {   
        videoPlayer = ExoPlayerFactory.newSimpleInstance( new DefaultRenderersFactory(mContext), new DefaultTrackSelector(), new DefaultLoadControl()); 
        videoPlayer.addListener(new Player.EventListener() {    
            @Override                  
            public void onTimelineChanged(Timeline timeline, Object manifest) {    
            }                       
            @Override                  
            public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {   
            }                      
            @Override                 
            public void onLoadingChanged(boolean isLoading) {      
            }                        
            @Override                
            public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {    
                if (playbackState == Player.STATE_ENDED) {     
                    releasePlayer();                  
                    ((MainActivity) getActivity()).executePlaylist(currentIndex + 1);           
                }                 
            }                 
            @Override          
            public void onRepeatModeChanged(int repeatMode) {   
            }                    
            @Override                
            public void onPlayerError(ExoPlaybackException error) {     
            }                        
            @Override             
            public void onPositionDiscontinuity() {            
            }                       
            @Override                  
            public void onPlaybackParametersChanged(PlaybackParameters playbackParameters) {    
            }          
        });                   
        playerView.setPlayer(videoPlayer);          
        playerView.setUseController(false);        
        videoPlayer.setPlayWhenReady(playWhenReady);    
        //videoPlayer.seekTo(currentWindow, playbackPosition);      
        MediaSource mediaSource = buildMediaSource(mContext);              
        videoPlayer.prepare(mediaSource, true, false);                
    }                  
    //==============================================================================================        
    // Prepare Video Source    
    //==============================================================================================    
    private MediaSource buildMediaSource(Context context) {             
    File dir = new File(filePath);           
    File file = new File(dir, filename);        
    videoUri = Uri.fromFile(file);                  
    // these are reused for both media sources we create below   
    DefaultExtractorsFactory extractorsFactory =                    
    new DefaultExtractorsFactory();                     
    DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(context,  Util.getUserAgent(context, "DanSignage"), null);  
    ExtractorMediaSource videoSource = new ExtractorMediaSource(videoUri, dataSourceFactory, extractorsFactory, null, null);    
    return videoSource;      
    }                  
    //======================================================

    // Release Video Player        
    //===============================================================      
    private void releasePlayer () {                    
        if (videoPlayer != null) {             
            playbackPosition = videoPlayer.getCurrentPosition();       
            currentWindow = videoPlayer.getCurrentWindowIndex();     
            playWhenReady = videoPlayer.getPlayWhenReady();             
            videoPlayer.release();              
            videoPlayer = null;      
        }         
    }
}