android surfaceView如何实现播放视频功能

<&#63;xml version="1.0" encoding="utf-8"&#63;>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".MainActivity">

  <com.example.examday11_4_1.surfaceview.MySurfaceView
    android:id="@+id/sv"
    android:layout_width="match_parent"
    android:layout_height="250dp" />

  <TextView
    android:id="@+id/te_nowTiem"
    android:textColor="#fff"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@id/sv"
    android:layout_marginLeft="60dp"
    android:layout_marginBottom="10dp"
    android:text="00:00" />

  <SeekBar
    android:id="@+id/sb"
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@id/sv"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="10dp" />

  <TextView
    android:id="@+id/te_allTiem"
    android:textColor="#fff"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@id/sv"
    android:layout_marginLeft="320dp"
    android:layout_marginBottom="10dp"
    android:text="00:00" />

  <Button
    android:id="@+id/but_play"
    android:layout_width="50dp"
    android:layout_height="40dp"
    android:layout_alignBottom="@+id/sv"
    android:layout_marginLeft="10dp"
    android:text="S/P"
    android:textSize="10sp" />

</RelativeLayout>

package com.example.examday11_4_1.surfaceview;

import android.content.Context;
import android.media.MediaPlayer;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import java.io.IOException;
import java.text.SimpleDateFormat;

public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback {
  private SurfaceHolder surfaceHolder;
  private MediaPlayer mediaPlayer;

  public MySurfaceView(Context context) {
    super(context);
  }

  public MySurfaceView(Context context, AttributeSet attrs) {
    super(context, attrs);
    surfaceHolder = getHolder();
    surfaceHolder.addCallback(this);
    if (mediaPlayer == null){
      mediaPlayer = new MediaPlayer();
    }
  }

  public MySurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
  }

  public MySurfaceView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
    super(context, attrs, defStyleAttr, defStyleRes);
  }

  public void setDataPath(String path){
    mediaPlayer.reset();
    try {
      mediaPlayer.setDataSource(path);
      mediaPlayer.prepareAsync();
      mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
        @Override
        public void onPrepared(MediaPlayer mp) {
          mediaPlayer.start();
        }
      });
    } catch (IOException e) {
      e.printStackTrace();
    }
  }


  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    mediaPlayer.setDisplay(surfaceHolder);
  }

  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
    if (mediaPlayer!=null){
      mediaPlayer.release();
      mediaPlayer = null;
    }
  }

  //暂停/开始播放
  public void playOrNo(){
    if (mediaPlayer!=null){
      if (mediaPlayer.isPlaying()){
        mediaPlayer.pause();
      }else {
        mediaPlayer.start();
      }
    }
  }

  //拖动更新进度
  public void seekTo(int progress){
    if (mediaPlayer!=null){
      int duration = mediaPlayer.getDuration();
      int current = progress * duration /100;
      mediaPlayer.seekTo(current);
    }
  }

  //获取播放进度
  public int getProgress(){
    if (mediaPlayer!=null){
      int druation = mediaPlayer.getDuration();
      int currentPosition = mediaPlayer.getCurrentPosition();
      int progress = currentPosition * 100 / druation;
      return progress;
    }
    return 0;
  }

  //获取播放时长
  public String getCurrentTime(){
    if (mediaPlayer!=null){
      long currentPostion = mediaPlayer.getCurrentPosition();
      SimpleDateFormat format = new SimpleDateFormat("mm:ss");
      String f = format.format(currentPostion);
      return f+"";

    }
    return "";
  }

  //获取时长
  public String getDuration(){
    if (mediaPlayer!=null){
      long duration = mediaPlayer.getDuration();
      SimpleDateFormat format = new SimpleDateFormat("mm:ss");
      return format.format(duration)+"";
    }
    return "";
  }

}

package com.example.examday11_4_1;

import android.Manifest;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.example.examday11_4_1.surfaceview.MySurfaceView;

import java.util.Timer;
import java.util.TimerTask;

public class MainActivity extends AppCompatActivity {

  private MySurfaceView mySurfaceView;
  private TextView teNowTiem;
  private SeekBar sb;
  private TextView teAllTiem;
  private Button butPlay;
  private Timer timer;
  private Handler handler = new Handler();
  private String path ="http://uvideo.spriteapp.cn/video/2019/0512/56488d0a-7465-11e9-b91b-1866daeb0df1_wpd.mp4";

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){
      requestPermissions(new String[]{
          Manifest.permission.READ_EXTERNAL_STORAGE
      },100);
    }
    initView();
    initTimer();

  }

  private void initTimer() {
    timer = new Timer();
    timer.schedule(new TimerTask() {
      @Override
      public void run() {
        final String currentTime = mySurfaceView.getCurrentTime();
        final String duration = mySurfaceView.getDuration();
        final int progress = mySurfaceView.getProgress();
        handler.post(new Runnable() {
          @Override
          public void run() {
            sb.setProgress(progress);//设置进度条
            teAllTiem.setText(duration);//设置总时长
            teNowTiem.setText(currentTime);//设置当前时长
          }
        });
      }
    },0,100);
  }

  private void initView() {
    mySurfaceView = (MySurfaceView) findViewById(R.id.sv);
    mySurfaceView.setDataPath(path);
    teNowTiem = (TextView) findViewById(R.id.te_nowTiem);
    sb = (SeekBar) findViewById(R.id.sb);
    teAllTiem = (TextView) findViewById(R.id.te_allTiem);
    butPlay = (Button) findViewById(R.id.but_play);

    //设置拖动
    sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
      @Override
      public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        if (fromUser){
          mySurfaceView.seekTo(progress);//视频播放拖动
        }
      }

      @Override
      public void onStartTrackingTouch(SeekBar seekBar) {

      }

      @Override
      public void onStopTrackingTouch(SeekBar seekBar) {

      }
    });

    //暂停播放
    butPlay.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        mySurfaceView.playOrNo();
      }
    });

  }
}