如何为 TextureView 设置动画?

How to animate TextureView?

我试图在 TextureView 中淡入淡出,但由于某种原因它没有动画。它只是简单地在视频中弹出,根本没有褪色,我真的不知道为什么会这样,因为经过一些研究我发现 TextureView 可以正常动画。

这是我的代码,希望大家能指点我一下。

PS,我省略了所有与纹理视图和动画无关的无关代码。

public class MainActivity extends AppCompatActivity implements MediaPlayer.OnPreparedListener, MediaPlayer.OnCompletionListener
{
    private static final String TAG = MainActivity.class.getSimpleName();

    private MediaPlayer mediaPlayer1;
    private ArrayList<Uri> videoUris = new ArrayList<>();
    private int current_video_index = 0;

    private TextureView textureView;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textureView = (TextureView) findViewById(R.id.textureView);

        mediaPlayer1 = new MediaPlayer();
        mediaPlayer1.setAudioStreamType(AudioManager.STREAM_MUSIC);
        mediaPlayer1.setOnPreparedListener(this);
        mediaPlayer1.setOnCompletionListener(this);

        initVideoUris();
        initNewVideo();
    }

    private void startVideo(final Uri uri)
    {
        textureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener()
        {
            @Override
            public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height)
            {
                try {
                    mediaPlayer1.setDataSource(MainActivity.this, uri);
                    mediaPlayer1.setSurface(new Surface(surface));
                    mediaPlayer1.setOnCompletionListener(MainActivity.this);
                    mediaPlayer1.setOnPreparedListener(MainActivity.this);
                    mediaPlayer1.setAudioStreamType(AudioManager.STREAM_MUSIC);

                    mediaPlayer1.prepareAsync();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height)
            {

            }

            @Override
            public boolean onSurfaceTextureDestroyed(SurfaceTexture surface)
            {
                return false;
            }

            @Override
            public void onSurfaceTextureUpdated(SurfaceTexture surface)
            {

            }
        });
    }

    @Override
    public void onPrepared(MediaPlayer mp)
    {
        mp.start();
        fadeInView(textureView);
    }

    @Override
    public void onCompletion(MediaPlayer mp)
    {
        if (!moreVideosAvailable())
        {
            finish();
        }
    }

    private boolean moreVideosAvailable()
    {
        return current_video_index < videoUris.size();
    }

    private void fadeInView(View view)
    {
        view.setAlpha(0f);
        view.setVisibility(View.VISIBLE);
        view.animate().alpha(1f).setDuration(2000).setListener(null).start();
    }
}

我通过制作一个使用 TextureView 作为显示视频的表面的 videoPlayerFragment 解决了这个问题。然后简单地为整个片段而不是 textureView 设置动画。