Android提高第一篇之MediaPlayer

本文来自http://blog.youkuaiyun.com/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(){ @Override public 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{ @Override public 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 block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.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 block e.printStackTrace(); } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } m.start(); } } } /* * SeekBar进度改变事件 */ class SeekBarChangeEvent implements SeekBar.OnSeekBarChangeListener{ @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { // TODO Auto-generated method stub } @Override public void onStartTrackingTouch(SeekBar seekBar) { isChanging=true; } @Override public void onStopTrackingTouch(SeekBar seekBar) { m.seekTo(seekBar.getProgress()); isChanging=false; } } }