Android 多媒体MediaPlayer使用详解

蔚落 2022-07-24 05:11 257阅读 0赞

现在的手机功能越来越丰富了，遥想10年前，MP3,MP4,MP5，还是很流行的，博主当时读高中时很想拥有一台，可以听音乐和看电影。可是条件有限，学校也禁止此东西，所以只能偷偷的玩。而现在我们的手机也很早以前就支持了这些功能，而且界面和功能也远远超过了MP4。好吧，说多了，今天本文介绍的是Andriod系统自带的Mediaplayer,和VideoView实现简单的音乐和视频的播放，至于想做出如酷狗音乐这样的APP的话，只要想做，应该也不难，都是基于此实现了功能的扩展。

Android的MediaPlayer包含了Audio和Video的播放功能，在Android的界面上，Music和Video两个应用程序都是调用MediaPlaer来实现的。

**一、播放音频文件**

首先看看MediaPlaer的生命周期

![Center][]

下面是MediaPlayer提供的常用方法

<table style="font-family:tahoma,arial,sans-serif; margin:0px; padding:0px; border-spacing:0px; border-style:solid; border-color:rgb(192,192,192); color:rgb(68,68,68); font-size:12px; line-height:18px"> 
 <tbody style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:0px"> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 方法</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 说明</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> MediaPlayer</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 构造方法</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> create</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 创建一个要播放的多媒体</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> getCurrentPosition</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 得到当前播放位置</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> getDuration</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 得到文件的时间</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> getVideoHeight</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 得到视频的高度</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> getVideoWidth</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 得到视频的宽度</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> isLooping</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 是否循环播放</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> isPlaying</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 是否正在播放</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> pause</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 暂停</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> prepare</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 准备（同步）</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> prepareAsync</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 准备（异步）</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> release</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 释放MediaPlayer对象相关的资源</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> reset</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 重置MediaPlayer对象为刚刚创建的状态</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> seekTo</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 指定播放的位置（以毫秒为单位的时间）</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setAudioStreamType</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置流媒体的类型</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setDataSource</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置多媒体数据来源(位置)</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setDisplay</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置用SurfaceHolder来显示多媒体</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setLooping</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置是否循环播放</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setOnButteringUpdateListener</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 网络流媒体的缓冲监听</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setOnErrorListener</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置错误信息监听</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setOnVideoSizeChangedListener</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 视频尺寸监听</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setScreenOnWhilePlaying</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置是否使用SurfaceHolder来保持屏幕显示</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> setVolume</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 设置音量</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> start</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 开始播放</td> 
  </tr> 
  <tr style="margin:0px; padding:0px"> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> stop</td> 
   <td style="font-family:'microsoft yahei',arial,simsun; margin:0px; padding:3px; border-style:solid; border-color:rgb(192,192,192); word-break:normal!important"> 停止播放</td> 
  </tr> 
 </tbody> 
</table>

MediaPlayer的工作流程是这样的：

1，首先创建MediaPlaer对象； \*

2，然后调用setDataSource()方法来设置音频文件的路径；\*\*

3，再调用prepare()方法使MediaPlayer进入到准备状态；

4，调用start方法就可以播放音频。

\*  创建MediaPlaer对象有两种方式

**a 直接new出来**

MediaPlayer mp = new MediaPlayer();

**b 使用create方式**

MediaPlayer mp = MediaPlayer.create(this, R.raw.test);//这时就不用调用setDataSource了

当然上面首先得在res文件夹下新建raw文件夹，并放置一个test文件

\*\* 设置播放的文件

MediaPlayer要播放的文件主要包括3个来源：  
**a. 用户在应用中事先自带的resource资源**  
例如：MediaPlayer.create(this, R.raw.test);  
**b. 存储在SD卡或其他文件路径下的媒体文件**  
例如：mp.setDataSource("/sdcard/test.mp3");  
**c. 网络上的媒体文件**  
例如：mp.setDataSource("http://www.citynorth.cn/music/confucius.mp3");  
**MediaPlayer的setDataSource一共四个方法：**  
setDataSource (String path)  
setDataSource (FileDescriptor fd)  
setDataSource (Context context, Uri uri)  
setDataSource (FileDescriptor fd, long offset, long length)  
  
其中使用FileDescriptor时，需要将文件放到与res文件夹平级的assets文件夹里，然后使用：  
AssetFileDescriptor fileDescriptor = getAssets().openFd("rain.mp3");  
m\_mediaPlayer.setDataSource(fileDescriptor.getFileDescriptor(),fileDescriptor.getStartOffset(), fileDescriptor.getLength());  
来设置datasource  
先简单看下效果图吧

![Center 1][]  
上面的功能一看就知道了，就不用我说了吧

下面是实现代码

activity\_main.xml

MainActivity.java

package com.example.musicplayer;
    
    import java.io.File;
    import java.io.IOException;
    
    import android.R.integer;
    import android.app.Activity;
    import android.media.MediaPlayer;
    import android.os.Bundle;
    import android.os.Environment;
    import android.os.Handler;
    import android.os.Message;
    import android.util.Log;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.SeekBar;
    import android.widget.SeekBar.OnSeekBarChangeListener;
    import android.widget.TextView;
    
    public class MainActivity extends Activity implements OnClickListener,
    		OnSeekBarChangeListener {
    	private Button play, pause, stop;
    	private MediaPlayer player;
    	private SeekBar mSeekBar;
    	private TextView tv, tv2;
    	private boolean hadDestroy = false;
    	private Handler mHandler = new Handler() {
    		public void handleMessage(android.os.Message msg) {
    
    			switch (msg.what) {
    			case 0x01:
    
    				break;
    
    			default:
    				break;
    			}
    		};
    	};
    	Runnable runnable = new Runnable() {
    
    		@Override
    		public void run() {
    
    			if (!hadDestroy) {
    				mHandler.postDelayed(this, 1000);
    				int currentTime = Math
    						.round(player.getCurrentPosition() / 1000);
    				String currentStr = String.format("%s%02d:%02d", "当前时间 ",
    						currentTime / 60, currentTime % 60);
    				tv.setText(currentStr);
    				mSeekBar.setProgress(player.getCurrentPosition());
    			}
    		}
    	};
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    		play = (Button) findViewById(R.id.play);
    		pause = (Button) findViewById(R.id.pause);
    		stop = (Button) findViewById(R.id.stop);
    		mSeekBar = (SeekBar) findViewById(R.id.seekbar);
    		tv = (TextView) findViewById(R.id.tv);
    		tv2 = (TextView) findViewById(R.id.tv2);
    		mSeekBar.setOnSeekBarChangeListener(this);
    		play.setOnClickListener(this);
    		pause.setOnClickListener(this);
    		stop.setOnClickListener(this);
    		player = new MediaPlayer();
    		initMediaplayer();
    
    	}
    
    	/**
    	 * 初始化播放器
    	 */
    	private void initMediaplayer() {
    		try {
    			File file = new File(Environment.getExternalStorageDirectory()
    					+ "/Download/", "aiqiu.mp3");
    			player.setDataSource(file.getPath());
    			Log.e("播放器", file.toString());
    			player.prepare();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    	@Override
    	public void onClick(View v) {
    		switch (v.getId()) {
    		case R.id.play:
    			if (!player.isPlaying()) {
    				player.start();
    				int totalTime = Math.round(player.getDuration() / 1000);
    				String str = String.format("%02d:%02d", totalTime / 60,
    						totalTime % 60);
    				tv2.setText(str);
    				mSeekBar.setMax(player.getDuration());
    				mHandler.postDelayed(runnable, 1000);
    			}
    
    			break;
    		case R.id.pause:
    			if (player.isPlaying()) {
    				player.pause();
    			}
    			break;
    		case R.id.stop:
    			if (player.isPlaying()) {
    				player.reset();
    				initMediaplayer();
    			}
    			break;
    
    		default:
    			break;
    		}
    	}
    
    	@Override
    	public void onProgressChanged(SeekBar seekBar, int progress,
    			boolean fromUser) {
    		if (player != null) {
    			player.seekTo(seekBar.getProgress());
    		}
    
    	}
    
    	@Override
    	public void onStartTrackingTouch(SeekBar seekBar) {
    		// TODO 自动生成的方法存根
    
    	}
    
    	@Override
    	public void onStopTrackingTouch(SeekBar seekBar) {
    		// TODO 自动生成的方法存根
    	}
    
    	@Override
    	protected void onDestroy() {
    		// TODO 自动生成的方法存根
    		super.onDestroy();
    		if (player != null) {
    			player.stop();
    			hadDestroy = true;
    			player.release();
    		}
    	}
    
    }

**二、播放视频文件**  
播放视频文件相比播放音频文件并不比它复杂，这里使用VideoView类来实现。这个类将视频的显示和控制集于一身。

VideoView和MediaPlaer也比较类似，主要有以下常用方法

<table style="text-align:center"> 
 <tbody> 
  <tr> 
   <td style="background:#D9D9D9"> <p><strong>方法名</strong></p> </td> 
   <td style="background:#D9D9D9"> <p><strong>功能描述</strong></p> </td> 
  </tr> 
  <tr> 
   <td> <p>setVideoPath()</p> </td> 
   <td> <p>设置要播放的视频文件的位置。</p> </td> 
  </tr> 
  <tr> 
   <td> <p>start()</p> </td> 
   <td> <p>开始或继续播放视频。</p> </td> 
  </tr> 
  <tr> 
   <td> <p>pause()</p> </td> 
   <td> <p>暂停播放视频。</p> </td> 
  </tr> 
  <tr> 
   <td> <p>resume()</p> </td> 
   <td> <p>将视频重头开始播放。</p> </td> 
  </tr> 
  <tr> 
   <td> <p>seekTo()</p> </td> 
   <td> <p>从指定的位置开始播放视频。</p> </td> 
  </tr> 
  <tr> 
   <td> <p>isPlaying()</p> </td> 
   <td> <p>判断当前是否正在播放视频。</p> </td> 
  </tr> 
  <tr> 
   <td> <p>getDuration()</p> </td> 
   <td> <p>获取载入的视频文件的时长。</p> </td> 
  </tr> 
 </tbody> 
</table>

因为VideoView是包装过的MediaPlayer,所以使用起来很相似。

比如：

private void initVideoPlayer() {
    		File file = new File(Environment.getExternalStorageDirectory()
    				+ "/Download/", "Sample.3gp");
    		videoPlayer.setVideoPath(file.getPath());// 指定视频文件的路径
    
    	}

事件处理

@Override
    	public void onClick(View v) {
    		switch (v.getId()) {
    		case R.id.play:
    			if (!videoPlayer.isPlaying()) {
    				videoPlayer.start();
    			}
    			break;
    		case R.id.pause:
    			if (videoPlayer.isPlaying()) {
    				videoPlayer.pause();
    			}
    			break;
    		case R.id.stop:
    			if (videoPlayer.isPlaying()) {
    				videoPlayer.resume();
    			}
    			break;
    
    		default:
    			break;
    		}
    	}

**三、常见的MediaPlayer错误**

也就是它的错误状态。比如这样的错误 start called in state 0，0表示他的错误状态，下面是MediaPlayer的状态，源码中找到的：

enum media_player_states {
            MEDIA_PLAYER_STATE_ERROR        = 0,           // 0状态
            MEDIA_PLAYER_IDLE                = 1 << 0,     // 1状态
            MEDIA_PLAYER_INITIALIZED        = 1 << 1,      // 2 状态
            MEDIA_PLAYER_PREPARING            = 1 << 2,    // 4 状态
            MEDIA_PLAYER_PREPARED            = 1 << 3,     // 8状态
            MEDIA_PLAYER_STARTED            = 1 << 4,      // 16状态
            MEDIA_PLAYER_PAUSED                = 1 << 5,   // 32状态
            MEDIA_PLAYER_STOPPED            = 1 << 6,      // 64 状态
            MEDIA_PLAYER_PLAYBACK_COMPLETE  = 1 << 7,      // 128 状态
        }

可以参照报错的状态和MediaPlayer的生命周期（上图）进行错误分析。

**好了，先写到这，对以上内容有疑惑或纰漏的地方，欢迎留言指出！**

[Center]: /images/20220722/1c4bc588ff1547fc86b176a0f26bee54.png
[Center 1]: /images/20220722/a46e28cb8fc64d678262e2de34d6798a.png