mp3播放器（六）（播放功能实现）

package com.example.mp3player00;

import java.io.File;

import model.Mp3Info;
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;

public class PlayerActivity extends Activity{
    ImageButton startButton=null;
    ImageButton pauseButton=null;
    ImageButton stopButton=null;
    MediaPlayer mediaPlayer=null;
    private boolean isPlaying=false;
    private boolean isPause=false;
    private boolean isReleased=false;
    Mp3Info mp3Info=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.player);
        Intent intent=getIntent();
         mp3Info=(Mp3Info) intent.getSerializableExtra("mp3Info");
        startButton=(ImageButton)findViewById(R.id.start);
        pauseButton=(ImageButton)findViewById(R.id.pause);
        stopButton=(ImageButton)findViewById(R.id.stop);
        startButton.setOnClickListener(new startButtonListener());
        pauseButton.setOnClickListener(new pauseButtonListener());
        stopButton.setOnClickListener(new stopButtonListener());
        
        
    }
    class startButtonListener implements OnClickListener{

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            if(!isPlaying){//如果不在播放
                String path=getMp3Path(mp3Info);
                mediaPlayer=MediaPlayer.create(PlayerActivity.this, Uri.parse("file://"+path));
                mediaPlayer.setLooping(false);
                mediaPlayer.start();
                isPlaying=true;
                isReleased=false;
            }
        }
        
    }
    class pauseButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if(!isPause){
                //如果当前不在暂停
                mediaPlayer.pause();
                isPause=true;
                isPlaying=false;
            }
            //如果当前在暂停的状态
            else{
                mediaPlayer.start();
                isPause=false;
                isPlaying=true;
            }
        }
        
    }
    class stopButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if(isPlaying){
                if(!isReleased){
                    mediaPlayer.stop();
                    mediaPlayer.release();//释放掉资源，当不再使用mediaPlayer
                    isReleased=true;
                }
                isPlaying=false;
            }
            
        }
        
    }
    private String getMp3Path(Mp3Info mp3Info)
    {
        String SDCardRoot=Environment.getExternalStorageDirectory().getAbsolutePath();
        String Path=SDCardRoot+File.separator+"mp3"+File.separator+mp3Info.getMp3Name();
        return Path;
        
    }
    
    
    

}