android 使用MideaPlayer API来播放简单的应用

采用的Activity来播放音乐

<?xml version="1.0" encoding="utf-8"?><resources>    <string name="hello">Hello World, HomeActivity!</string>    <string name="app_name">音乐播放器</string>    <string name="filename">音乐文件</string>    <string name="play">播放</string>    <string name="pause">暂停</string>    <string name="stop">停止</string>    <string name="replay">重播</string></resources>

<?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"    ><TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/filename"    /><EditText      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:id="@+id/filenmae"    />        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="horizontal"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    >    <Button    android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:id="@+id/play"    android:text="@string/play"    />    <Button    android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:id="@+id/pause"    android:text="@string/pause"    />    <Button    android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:id="@+id/stop"    android:text="@string/stop"    />    <Button    android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:id="@+id/replay"    android:text="@string/replay"    />            </LinearLayout></LinearLayout>

package com.zyq.mp3;import java.io.File;import java.io.IOException;import android.app.Activity;import android.media.MediaPlayer;import android.os.Bundle;import android.os.Environment;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class HomeActivity extends Activity {private EditText filename;private File file;private MediaPlayer mediaPlayer;private int position;    @Override    public void onCreate(Bundle savedInstanceState)     {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                mediaPlayer = new MediaPlayer();                filename = (EditText)this.findViewById(R.id.filenmae);        Button play = (Button)this.findViewById(R.id.play);        Button pause = (Button)this.findViewById(R.id.pause);        Button stop = (Button)this.findViewById(R.id.stop);        Button replay = (Button)this.findViewById(R.id.replay);                ButtonListener l = new ButtonListener();        play.setOnClickListener(l);        pause.setOnClickListener(l);        stop.setOnClickListener(l);        replay.setOnClickListener(l);    }    //模拟电话接听，触发Activity onPause生命周期函数    @Override    protected void onPause()    {    if(mediaPlayer.isPlaying())    {    position = mediaPlayer.getCurrentPosition();//保存音乐播放的进度    mediaPlayer.stop();    }    super.onPause();    }        //模拟电话挂断，重新回到音乐播放界面，触发Activity onResume生命周期函数    @Override    protected void onResume()    {    try{if(file!=null && position > 0){play();mediaPlayer.seekTo(position);}} catch (IllegalArgumentException e){// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalStateException e){// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e){// TODO Auto-generated catch blocke.printStackTrace();}    super.onResume();    }    //模拟系统内存不足，KILL掉此Activity，触发的onSaveInstanceState 方法来保存参数    @Override    protected void onSaveInstanceState(Bundle outState)    {    if(file != null)    {    outState.putString("path", file.getAbsolutePath());    }    outState.putInt("position", position);    super.onSaveInstanceState(outState);    }    //模拟系统内存不足，回复此Activity，触发的onRestoreInstanceState 重新设置参数    @Override    protected void onRestoreInstanceState(Bundle savedInstanceState)    {    String path = savedInstanceState.getString("path");    if(path != null && "".equals(path))    {    this.file = new File(path);    }    this.position = savedInstanceState.getInt("position");    super.onRestoreInstanceState(savedInstanceState);    }    @Override    protected void onDestroy()    {    super.onDestroy();        mediaPlayer.release();    }    private class ButtonListener implements View.OnClickListener    {    private boolean flag;    @Overridepublic void onClick(View v){try{switch (v.getId()){case R.id.play:file = new File(Environment.getExternalStorageDirectory(),filename.getText().toString());if(file.exists()){Toast.makeText(HomeActivity.this, "音乐文件不存在", 1).show();return;}play();break;case R.id.pause:if(mediaPlayer.isPlaying()){mediaPlayer.pause();flag = true;((Button)v).setText("继续");}else{if(flag){mediaPlayer.start();((Button)v).setText("暂停");}}break;case R.id.stop:if(mediaPlayer.isPlaying()){mediaPlayer.seekTo(0);}else{if(file.exists()){play();}}break;case R.id.replay:if(mediaPlayer.isPlaying()){mediaPlayer.stop();}break;default:break;}} catch (IllegalArgumentException e){// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalStateException e){// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e){// TODO Auto-generated catch blocke.printStackTrace();}}        }    //播放音乐    private void play() throws IllegalArgumentException, IllegalStateException, IOException    {    mediaPlayer.reset();    mediaPlayer.setDataSource(file.getAbsolutePath());mediaPlayer.prepare();mediaPlayer.start();    }}