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(){
            @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;
    }

  }

}