Android TextureView简易教程

简介

在Android开发中，TextureView是一个强大的视图类，用于在界面上显示可旋转、缩放和裁剪的视频、图像等内容。与普通的SurfaceView相比，TextureView提供了更好的渲染性能和更多的自定义功能。本教程将介绍如何使用TextureView来显示视频，并实现简单的手势操作。

创建TextureView

在XML布局文件中添加TextureView：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextureView
        android:id="@+id/textureView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

初始化TextureView

在活动或碎片中引用并初始化TextureView：

private TextureView mTextureView;

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

    mTextureView = findViewById(R.id.textureView);
    mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
}

private TextureView.SurfaceTextureListener mSurfaceTextureListener = new TextureView.SurfaceTextureListener() {
    @Override
    public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height) {
        // TextureView可用时执行的操作
    }

    @Override
    public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int width, int height) {
        // TextureView尺寸变化时执行的操作
    }

    @Override
    public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
        // TextureView销毁时执行的操作
        return false;
    }

    @Override
    public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
        // TextureView更新时执行的操作
    }
};

播放视频

使用MediaPlayer来播放视频：

private MediaPlayer mMediaPlayer;

private void playVideo() {
    SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture();
    if (surfaceTexture != null) {
        Surface surface = new Surface(surfaceTexture);
        try {
            AssetFileDescriptor afd = getAssets().openFd("video.mp4");
            mMediaPlayer = new MediaPlayer();
            mMediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
            mMediaPlayer.setSurface(surface);
            mMediaPlayer.prepareAsync();
            mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mp) {
                    mMediaPlayer.start();
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

手势操作

通过GestureDetector来实现简单的手势操作，例如手指缩放来进行视频的放大和缩小：

private ScaleGestureDetector mScaleGestureDetector;

private void setupGestureDetector() {
    mScaleGestureDetector = new ScaleGestureDetector(this, new ScaleGestureDetector.SimpleOnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float scale = detector.getScaleFactor();
            // 根据缩放比例来进行视频的放大和缩小操作
            return true;
        }
    });

    mTextureView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            mScaleGestureDetector.onTouchEvent(event);
            return true;
        }
    });
}

总结

通过以上简单的步骤，你已经可以使用TextureView来显示视频，并实现基本的手势操作。TextureView在Android开发中非常有用，可以提供高性能的渲染效果和更多的自定义功能。希望本教程对你有所帮助！

本文来自极简博客，作者：星辰漫步，转载请注明原文链接：Android TextureView简易教程