<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity" > <EditText  android:id="@+id/et_path"  android:layout_width="fill_parent"  android:layout_height="wrap_content"  android:hint="請輸入音樂文件的路徑" /> <LinearLayout  android:layout_width="fill_parent"  android:layout_height="wrap_content"  android:orientation="horizontal" >  <Button   android:id="@+id/bt_play"   android:layout_width="0dip"   android:layout_height="wrap_content"   android:layout_weight="1"   android:text="播放" />  <Button   android:id="@+id/bt_pause"   android:layout_width="0dip"   android:layout_height="wrap_content"   android:layout_weight="1"   android:text="暫停" />  <Button   android:id="@+id/bt_replay"   android:layout_width="0dip"   android:layout_height="wrap_content"   android:layout_weight="1"   android:text="重播" />  <Button   android:id="@+id/bt_stop"   android:layout_width="0dip"   android:layout_height="wrap_content"   android:layout_weight="1"   android:text="停止" /> </LinearLayout></LinearLayout>

package com.wuyudong.mp3player;import java.io.File;import java.io.IOException;import android.media.AudioManager;import android.media.MediaPlayer;import android.media.MediaPlayer.OnCompletionListener;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity implements OnClickListener { private EditText et_path; private Button bt_play, bt_replay, bt_pause, bt_stop; private MediaPlayer mediaPlayer; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  et_path = (EditText) findViewById(R.id.et_path);  bt_play = (Button) findViewById(R.id.bt_play);  bt_replay = (Button) findViewById(R.id.bt_replay);  bt_pause = (Button) findViewById(R.id.bt_pause);  bt_stop = (Button) findViewById(R.id.bt_stop);  bt_pause.setOnClickListener(this);  bt_play.setOnClickListener(this);  bt_replay.setOnClickListener(this);  bt_stop.setOnClickListener(this); } @Override public void onClick(View v) {  switch (v.getId()) {  case R.id.bt_play:   play();   break;  case R.id.bt_replay:   replay();   break;  case R.id.bt_stop:   stop();   break;  case R.id.bt_pause:   pause();   break;  default:   break;  } } /**  * 暫停音樂  */ private void pause() {  if ("繼續(xù)".equals(bt_pause.getText().toString().trim())) {   mediaPlayer.start();   bt_pause.setText("暫停");   return;  }  if (mediaPlayer != null && mediaPlayer.isPlaying()) {   mediaPlayer.pause();   bt_pause.setText("繼續(xù)");   return;  } } /**  * 重新播放  */ private void replay() {  if (mediaPlayer != null && mediaPlayer.isPlaying()) {   mediaPlayer.seekTo(0);   return;  }  play(); } /**  * 停止播放音樂  */ private void stop() {  if (mediaPlayer != null && mediaPlayer.isPlaying()) {   mediaPlayer.stop();   mediaPlayer.release(); // 記得釋放資源   mediaPlayer = null;   bt_play.setEnabled(true);  } } /**  * 播放音樂  */ private void play() {  String path = et_path.getText().toString().trim();  File file = new File(path);  if (file.exists() && file.length() > 0) {   try {    mediaPlayer = new MediaPlayer();    mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);    mediaPlayer.setDataSource(path);    mediaPlayer.prepare(); // might take long! (for buffering, etc)    mediaPlayer.start();    mediaPlayer.setOnCompletionListener(new OnCompletionListener() {     @Override     public void onCompletion(MediaPlayer mp) {      bt_play.setEnabled(true);     }    } );        bt_play.setEnabled(false);   } catch (Exception e) {    Toast.makeText(this, "播放失敗", 0).show();    e.printStackTrace();   }  } else {   Toast.makeText(this, "文件不存在", 0).show();  } }}