android中播放视频

在android中播放视频主要是通过VideoView类实现。这个类将视频的显示和控制集于一身，用起来非常的简单和方便。

下面就用VideoView实现一个简单的播放器。新建一个PlayVideo项目

activity_main.xml中的代码如下：

布局文件中添加了三个按钮用于控制视频的播放和一个VideoView控件用于视频的显示

AndroidManifest.xml中的代码如下：

由于程序要访问sd卡，所以需要申请WRITE_EXTERNAL_STORAGE权限

MainActivity中的代码如下：

package com.tangliang.playvideo;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.widget.VideoView;

import java.io.File;

public class MainActivity extends AppCompatActivity {

    private VideoView videoView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        videoView = (VideoView) findViewById(R.id.videoView);
        Button play = (Button) findViewById(R.id.play);
        Button pause = (Button) findViewById(R.id.pause);
        Button replay = (Button) findViewById(R.id.replay);
        play.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(!videoView.isPlaying()){
                    videoView.start();
                }
            }
        });
        pause.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(videoView.isPlaying()){
                    videoView.pause();
                }
            }
        });
        replay.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(videoView.isPlaying()){
                    videoView.resume();
                }
            }
        });
        if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
        }
        else{
            initVideoPath();
        }
    }

    private void initVideoPath(){
        File file = new File(Environment.getExternalStorageDirectory(), "shosanjiusan.mp4");
        videoView.setVideoPath(file.getPath());
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                    initVideoPath();
                }
                else{
                    Toast.makeText(this, "拒绝权限将无法使用程序", Toast.LENGTH_SHORT).show();
                    finish();
                }
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(videoView != null){
            videoView.suspend();
        }
    }
}