<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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:orientation="vertical"
    android:layout_height="match_parent"
    tools:context="com.videodemo.MainActivity">

    <VideoView
        android:id="@+id/videoView"
        android:layout_width="match_parent"
        android:layout_height="300dp" />
    
<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        
<Button
            android:id="@+id/btn_start"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="开始"
            android:layout_marginLeft="20dp"/>

        <Button
            android:id="@+id/btn_end"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="结束" />

 </LinearLayout>

</LinearLayout>

package com.example.a123.videodemo;

import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.VideoView;

public class MainActivity extends AppCompatActivity {
    private VideoView videoView;
    private Button btn_start,btn_end;
    private MediaController mediaController;

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

    private void initView() {
        videoView= (VideoView) findViewById(R.id.videoView);
        btn_start= (Button) findViewById(R.id.btn_start);
        btn_end= (Button) findViewById(R.id.btn_end);

        btn_start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                init();
            }
        });

        btn_end.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                videoView.stopPlayback();
            }
        });
}

    private void init() {
        videoView = (VideoView) findViewById(R.id.videoView);
        mediaController = new MediaController(this);
        String uri = "android.resource://" + getPackageName() + "/" +R.raw.aas;
        videoView.setVideoURI(Uri.parse(uri));
        videoView.setMediaController(mediaController);
        mediaController.setMediaPlayer(videoView);
        videoView.requestFocus();
        videoView.start();
    }
}