音乐播放器的实现(简易版)

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

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="女神牌音乐播放器(章泽天,我的女神)"
/>

<EditText
android:id="@+id/et_name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="2.mp3"
/>

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal">

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="播放"
android:onClick="play"
/>

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="暂停"
android:onClick="pause"
/>

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="停止"
android:onClick="stop"
/>

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="重播"
android:onClick="reset"
/>

</LinearLayout>
</LinearLayout>

package com.njupt.mp3_1;

import java.io.File;

import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.content.Context;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

private MediaPlayer mp;
private File file;
private EditText et_name;
private boolean pause;
private int position = 0;
private TelephonyManager tm;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

et_name = (EditText) findViewById(R.id.et_name);
tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
tm.listen(new MyPhoneStateListener(), PhoneStateListener.LISTEN_CALL_STATE);
}

private class MyPhoneStateListener extends PhoneStateListener{
@Override
public void onCallStateChanged(int state, String incomingNumber) {
super.onCallStateChanged(state, incomingNumber);

switch (state) {
case TelephonyManager.CALL_STATE_IDLE:
if(position > 0 && mp != null){
mp.seekTo(position);
mp.start();
}
break;
case TelephonyManager.CALL_STATE_OFFHOOK:
if(mp!= null){
if(mp.isPlaying()){
position = mp.getCurrentPosition();
mp.pause();
}
}

case TelephonyManager.CALL_STATE_RINGING:
if(mp != null){
if(mp.isPlaying()){
position = mp.getCurrentPosition();
mp.pause();
}
}
default:
break;
}
}
}

public void play(View v){
String name = et_name.getText().toString();
file = new File(Environment.getExternalStorageDirectory(),name);
if(!file.exists()){
Toast.makeText(this, "sorry,文件不存在", 1).show();
}else{
play();
}
}

public void play(){
try{
mp = new MediaPlayer();
mp.reset();
mp.setDataSource(file.getAbsolutePath());
mp.prepare();
mp.setOnPreparedListener(new MyOnPreparedListener());
}catch(Exception e){
e.printStackTrace();
}

}

private class MyOnPreparedListener implements OnPreparedListener{
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
}
}

public void pause(View v){
Button bt = (Button) v;

if(mp != null){
if(mp.isPlaying()){
mp.pause();
bt.setText("继续");
pause = true;
}else{
if(pause){
mp.start();
bt.setText("暂停");
pause = false;
}
}
}
}

public void stop(View v){
if(mp != null){
mp.stop();
}
}

public void reset(View v){
stop(v);
play(v);
}

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

if(mp != null){
mp.release();
mp = null;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

<uses-permission android:name="android.permission.READ_PHONE_STATE"/>