ANDROID_MARS学习笔记_S01原始版_023_MP3PLAYER003_播放mp3

一、简介

1.在onListItemClick中实现点击条目时，跳转到PlayerActivity,mp3info通过Intent传给PlayerActivity

2.PlayerActivity通过android.media.MediaPlayer实现播放，暂停、停止

二、代码
1.xml
(1)player.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:orientation="horizontal" android:paddingLeft="10dip"
    android:paddingRight="10dip" android:paddingTop="1dip"
    android:paddingBottom="1dip">
    <ImageButton android:id="@+id/begin" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:src="@drawable/begin" />
    <ImageButton android:id="@+id/pause" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:src="@drawable/pause" />
    <ImageButton android:id="@+id/stop" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:src="@drawable/stop" />
</LinearLayout>

(2)AndroidManifest.xml注册activity

<activity android:name=".PlayerActivity" android:label="@string/app_name"/>

2.java
(1)LocalMp3ListActivity.java

点击歌曲时，启动PlayerActivity

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        Mp3Info info = infos.get(position);
        Intent intent = new Intent();
        intent.putExtra("mp3Info", info);
        intent.setClass(this, PlayerActivity.class);
        startActivity(intent);
    }

(2)PlayerActivity.java

package tony.mp3player;

import java.io.File;

import tony.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 {

    private ImageButton beginBtn = null;
    private ImageButton pauseBtn = null;
    private ImageButton stopBtn = null;
    
    private MediaPlayer mediaPlayer = null;
    private Mp3Info info = null;
    
    private boolean isPlaying = false;
    private boolean isPause = false;
    private boolean isRelease = false;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.player);
        Intent intent = getIntent();
        info = (Mp3Info) intent.getSerializableExtra("mp3Info");
        beginBtn = (ImageButton) findViewById(R.id.begin);
        pauseBtn = (ImageButton) findViewById(R.id.pause);
        stopBtn = (ImageButton) findViewById(R.id.stop);
        
        beginBtn.setOnClickListener(new BeginListener());
        pauseBtn.setOnClickListener(new PauseListener());
        stopBtn.setOnClickListener(new StopListener());
    }
    
    class BeginListener implements OnClickListener {
        @Override
        public void onClick(View v) {
            if(!isPlaying) {
                String path = getMp3Path(info.getMp3Name());
                mediaPlayer = MediaPlayer.create(PlayerActivity.this, Uri.parse("file://" + path));
                mediaPlayer.start();
                isPlaying = true;
                isRelease = false;
            }
        }
    }
    
    class PauseListener implements OnClickListener {
        @Override
        public void onClick(View v) {
            if(mediaPlayer != null) {
                if(!isRelease){
                    if(!isPause) {
                        mediaPlayer.pause();
                        isPause = true;
                    } else {
                        mediaPlayer.start();
                        isPause = false;
                    }
                }
            }
        }
    }
    
    class StopListener implements OnClickListener {
        @Override
        public void onClick(View v) {
            if(mediaPlayer != null) {
                if(isPlaying) {
                    if(!isRelease) {
                        mediaPlayer.stop();
                        mediaPlayer.release();
                        isRelease = true;
                        isPlaying = false;
                    }
                }
            }
        }
    }
    
    private String getMp3Path(String mp3Name) {
        String sdCartRoot = Environment.getExternalStorageDirectory().getAbsolutePath();
        String path = sdCartRoot + File.separator + "mp3" + File.separator + mp3Name;
        return path;
    }
}