Android提高第一篇之MediaPlayer

本文来自http://blog.csdn.net/hellogv/ ，引用必须注明出处！ 

        前面写了十四篇关于界面的入门文章，大家都看完和跟着练习之后，对于常用的Layout和View都会有一定的了解了,接下来的文章就不再强调介绍界面了，而是针对具体的常见功能而展开。

        本文介绍MediaPlayer的使用。MediaPlayer可以播放音频和视频，另外也可以通过VideoView来播放视频，虽然VideoView比MediaPlayer简单易用，但定制性不如用MediaPlayer，要视情况选择了。MediaPlayer播放音频比较简单，但是要播放视频就需要SurfaceView。SurfaceView比普通的自定义View更有绘图上的优势，它支持完全的OpenGL ES库。

         先贴出本文程序运行结果的截图，上面是播放/停止音频，可用SeekBar来调进度，下面是播放/停止视频，也是用SeekBar来调进度：

 

main.xml的源码:

<?xml version="1.0" encoding="utf-8"?><LinearLayout android:id="@+id/LinearLayout01"android:layout_width="fill_parent" android:layout_height="fill_parent"xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"><SeekBar android:id="@+id/SeekBar01" android:layout_height="wrap_content"android:layout_width="fill_parent"></SeekBar><LinearLayout android:id="@+id/LinearLayout02"android:layout_width="wrap_content" android:layout_height="wrap_content"><Button android:id="@+id/Button01" android:layout_width="wrap_content"android:layout_height="wrap_content" android:text="播放音频"></Button><Button android:id="@+id/Button02" android:layout_width="wrap_content"android:layout_height="wrap_content" android:text="停止播放"></Button></LinearLayout><SeekBar android:id="@+id/SeekBar02" android:layout_height="wrap_content"android:layout_width="fill_parent"></SeekBar><SurfaceView android:id="@+id/SurfaceView01"android:layout_width="fill_parent" android:layout_height="250px"></SurfaceView><LinearLayout android:id="@+id/LinearLayout02"android:layout_width="wrap_content" android:layout_height="wrap_content"><Button android:layout_width="wrap_content"android:layout_height="wrap_content" android:id="@+id/Button03"android:text="播放视频"></Button><Button android:layout_width="wrap_content"android:layout_height="wrap_content" android:text="停止播放" android:id="@+id/Button04"></Button></LinearLayout></LinearLayout>

 

本文程序的源码，有点长：

package com.testMedia;import java.io.IOException; import java.util.Timer;import java.util.TimerTask;import android.app.Activity; import android.media.AudioManager;import android.media.MediaPlayer;import android.os.Bundle; import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View; import android.widget.Button; import android.widget.SeekBar;import android.widget.Toast; public class testMedia extends Activity { /** Called when the activity is first created. */ private SeekBar skb_audio=null; private Button btn_start_audio = null; private Button btn_stop_audio = null; private SeekBar skb_video=null; private Button btn_start_video = null; private Button btn_stop_video = null; private SurfaceView surfaceView; private SurfaceHolder surfaceHolder; private MediaPlayer m = null; private Timer mTimer; private TimerTask mTimerTask; private boolean isChanging=false;//互斥变量，防止定时器与SeekBar拖动时进度冲突 @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //----------Media控件设置---------// m=new MediaPlayer(); //播放结束之后弹出提示 m.setOnCompletionListener(new MediaPlayer.OnCompletionListener(){@Overridepublic void onCompletion(MediaPlayer arg0) {Toast.makeText(testMedia.this, "结束", 1000).show();m.release();} }); //----------定时器记录播放进度---------// mTimer = new Timer(); mTimerTask = new TimerTask() { @Override public void run() { if(isChanging==true) return; if(m.getVideoHeight()==0) skb_audio.setProgress(m.getCurrentPosition()); else skb_video.setProgress(m.getCurrentPosition()); } }; mTimer.schedule(mTimerTask, 0, 10); btn_start_audio = (Button) this.findViewById(R.id.Button01); btn_stop_audio = (Button) this.findViewById(R.id.Button02); btn_start_audio.setOnClickListener(new ClickEvent()); btn_stop_audio.setOnClickListener(new ClickEvent()); skb_audio=(SeekBar)this.findViewById(R.id.SeekBar01); skb_audio.setOnSeekBarChangeListener(new SeekBarChangeEvent()); btn_start_video = (Button) this.findViewById(R.id.Button03); btn_stop_video = (Button) this.findViewById(R.id.Button04); btn_start_video.setOnClickListener(new ClickEvent()); btn_stop_video.setOnClickListener(new ClickEvent()); skb_video=(SeekBar)this.findViewById(R.id.SeekBar02); skb_video.setOnSeekBarChangeListener(new SeekBarChangeEvent()); surfaceView = (SurfaceView) findViewById(R.id.SurfaceView01); surfaceHolder = surfaceView.getHolder(); surfaceHolder.setFixedSize(100, 100); surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } /* * 按键事件处理 */ class ClickEvent implements View.OnClickListener{@Overridepublic void onClick(View v) {if(v==btn_start_audio){m.reset();//恢复到未初始化的状态m=MediaPlayer.create(testMedia.this, R.raw.big);//读取音频skb_audio.setMax(m.getDuration());//设置SeekBar的长度try {m.prepare();//准备} catch (IllegalStateException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}m.start();//播放}else if(v==btn_stop_audio || v==btn_stop_video){m.stop();}else if(v==btn_start_video){m.reset();//恢复到未初始化的状态m=MediaPlayer.create(testMedia.this, R.raw.test);//读取视频skb_video.setMax(m.getDuration());//设置SeekBar的长度m.setAudioStreamType(AudioManager.STREAM_MUSIC);m.setDisplay(surfaceHolder);//设置屏幕try { m.prepare(); } catch (IllegalArgumentException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalStateException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}m.start();}} } /* * SeekBar进度改变事件 */ class SeekBarChangeEvent implements SeekBar.OnSeekBarChangeListener{@Overridepublic void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser) {// TODO Auto-generated method stub}@Overridepublic void onStartTrackingTouch(SeekBar seekBar) { isChanging=true;}@Overridepublic void onStopTrackingTouch(SeekBar seekBar) {m.seekTo(seekBar.getProgress()); isChanging=false;} }}