1.效果图：

2.清单文件：文件读取权限

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

3.主界面：

package com.example.administrator.testz;import androidx.appcompat.app.AppCompatActivity;import android.graphics.Matrix;
import android.graphics.SurfaceTexture;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Surface;
import android.view.TextureView;import java.io.IOException;public class MainActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener,MediaPlayer.OnPreparedListener,MediaPlayer.OnErrorListener,MediaPlayer.OnBufferingUpdateListener,MediaPlayer.OnVideoSizeChangedListener {private String videoPath = Environment.getExternalStorageDirectory().getPath()+"/video.mp4";private TextureView textureView;private MediaPlayer mediaPlayer;private SurfaceTexture surfaceTexture;private Surface surface;private final static String TAG = "MainActivity";private int mVideomode=0;private int mVideoWidth;private int mVideoHeight;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);textureView = findViewById(R.id.id_textureview);textureView.setSurfaceTextureListener(this);}@Overrideprotected void onResume() {super.onResume();if (textureView.isAvailable()){playVideo();}}@Overrideprotected void onPause() {super.onPause();if (surfaceTexture != null){surfaceTexture.release();}if (mediaPlayer != null){mediaPlayer.release();mediaPlayer = null;}}@Overridepublic void onBufferingUpdate(MediaPlayer mp, int percent) {Log.e("TAG","Buffering:"+percent);}@Overridepublic boolean onError(MediaPlayer mp, int what, int extra) {return false;}@Overridepublic void onPrepared(MediaPlayer mp) {if (mp!=null){mediaPlayer.setVolume(1f,1f);mediaPlayer.start();}}@Overridepublic void onVideoSizeChanged(MediaPlayer mp, int width, int height) {mVideoWidth = mp.getVideoWidth();mVideoHeight = mp.getVideoHeight();updateTextureViewSizeCenter();}@Overridepublic void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {playVideo();}@Overridepublic void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {updateTextureViewSizeCenter();}@Overridepublic boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {return false;}@Overridepublic void onSurfaceTextureUpdated(SurfaceTexture surface) {}private void updateTextureViewSizeCenter() {float sx = (float)textureView.getWidth() / (float)mVideoWidth;float sy = (float)textureView.getHeight() / (float)mVideoHeight;Matrix matrix = new Matrix();matrix.preTranslate((textureView.getWidth() - mVideoWidth) / 2, (textureView.getHeight() - mVideoHeight) / 2);matrix.preScale(mVideoWidth / (float)textureView.getWidth(), mVideoHeight / (float)textureView.getHeight());if (sx >= sy) {matrix.postScale(sy, sy, textureView.getWidth() / 2, textureView.getHeight() / 2);} else {matrix.postScale(sx, sx, textureView.getWidth() / 2, textureView.getHeight() / 2);}textureView.setTransform(matrix);textureView.postInvalidate();//放大三倍matrix.setScale(1 + 0 / 100f, 1 + 0 / 100f);textureView.setTransform(matrix);}private void playVideo() {if (mediaPlayer == null){surfaceTexture = textureView.getSurfaceTexture();surface = new Surface(surfaceTexture);initMediaPlayer();}}private void initMediaPlayer() {mediaPlayer = new MediaPlayer();try{mediaPlayer.setDataSource(videoPath);mediaPlayer.setSurface(surface);mediaPlayer.prepareAsync();mediaPlayer.setOnPreparedListener(this);mediaPlayer.setOnErrorListener(this);mediaPlayer.setOnBufferingUpdateListener(this);mediaPlayer.setOnVideoSizeChangedListener(this);mediaPlayer.setLooping(true);}catch (IOException e){e.printStackTrace();}}}

4.布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:id="@+id/layout"android:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MainActivity"><TextureViewandroid:layout_alignParentRight="true"android:id="@+id/id_textureview"android:layout_width="match_parent"android:layout_height="match_parent" /></RelativeLayout>

end