Android MediaPlayer实现音乐播放

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
 >

<EditText 
android:id="@+id/edit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Demons.mp3"/>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
 >
<Button
 android:id="@+id/player"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开始播放"/>
<Button
 android:id="@+id/pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="暂停"/>
<Button
 android:id="@+id/restrat"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="重播"/>
<Button
 android:id="@+id/stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="停止"/>


</LinearLayout>

</LinearLayout>

MediaActivity 类

package com.sun.activity;

import java.io.File;
import java.io.IOException;

import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MediaActivity extends Activity implements OnClickListener{
private  MediaPlayer mediaPlayer;
private EditText editText;
private Button buttonPause;
private int posi=0;//用于记录播放的位置
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button buttonStrat=(Button) findViewById(R.id.player);
         buttonPause=(Button) findViewById(R.id.pause);
        Button buttonRestrat=(Button) findViewById(R.id.restrat);
        Button buttonStop=(Button) findViewById(R.id.stop);
        editText=(EditText) findViewById(R.id.edit);
//添加单击事件
        buttonStrat.setOnClickListener(this);
        buttonPause.setOnClickListener(this);
        buttonRestrat.setOnClickListener(this);
        buttonStop.setOnClickListener(this);
//创建播放器对象
         mediaPlayer= new MediaPlayer();

    }



/*@Override
 protected void onPause() {
 super.onPause();
 if(mediaPlayer.isPlaying()){
 //用于记录播放的位置
 posi=mediaPlayer.getCurrentPosition();
 mediaPlayer.pause();
 }
 }



 @Override
 protected void onStart() {
 super.onStart();

 if(posi!=0){
 mediaPlayer.seekTo(posi);
 mediaPlayer.start();
 }

 }
*/


@Override
public void onClick(View v) {
switch(v.getId())
            {

case R.id.player://播放

                    play();
break;
case R.id.pause://暂停
if(mediaPlayer.isPlaying())
                    {
//用于记录播放的位置
                        posi=mediaPlayer.getCurrentPosition();
                        mediaPlayer.pause();
                        buttonPause.setText("继续播放");
                    }else{
                        mediaPlayer.seekTo(posi);
                        mediaPlayer.start();
                        buttonPause.setText("暂停");
                    }

break;
case R.id.restrat://重播

if(mediaPlayer.isPlaying())
                    {

                        mediaPlayer.seekTo(0);
                    }else{
                        play();
                    }

break;
case R.id.stop://停止
if(mediaPlayer.isPlaying())


                    mediaPlayer.stop();
break;
            }
    }
public void play()
    {
        String mp3Name=editText.getText().toString();
        String path=Environment.getExternalStorageDirectory().toString();
        File file=new File(Environment.getExternalStorageDirectory(), mp3Name);
if(file.exists())
        {
try {
//告诉mediaplayer播放文件的位置
                mediaPlayer.setDataSource(file.getPath());
//加载缓存
                mediaPlayer.prepare();
//用于监听是否缓存完成
                mediaPlayer.setOnPreparedListener(new Prepared());
            } catch (Exception e) {
                e.printStackTrace();
            } 
        }else{
            Toast.makeText(this, "没有该文件", 1).show();
        }
    }


    class Prepared implements OnPreparedListener{

//缓存完毕后会调用onPrepared
public void onPrepared(MediaPlayer mp) {
            mediaPlayer.start();
        }

    }


}