21天学习android开发教程之MediaPlayer

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:

<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">
  <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 android:id="@+id/button02" android:layout_width="wrap_content" 
      android:layout_height="wrap_content" android:text="停止播放">
  
  <seekbar android:id="@+id/seekbar02" android:layout_height="wrap_content" 
    android:layout_width="fill_parent">

  <surfaceview android:id="@+id/surfaceview01" 
    android:layout_width="fill_parent" android:layout_height="250px">
  <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 android:layout_width="wrap_content" 
      android:layout_height="wrap_content" android:text="停止播放" android:id="@+id/button04">

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;  
  }
   
 }

}

以上就是21天学习android开发教程第一篇关于mediaplayer的相关介绍，希望对大家的学习有所帮助。