3.1.4 简单音乐播放器实现

package com.example.sample3_2;

import java.io.IOException;

import com.example.sample3_2.R;

import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MyActivity extends Activity {//Activity创建时调用
    private Button bPlay;           //播放按钮
    private Button bPause;          //暂停按钮
    private Button bStop;           //停止按钮
    private Button bAdd;           //增大音量
    private Button bReduce;         //降低音量
    private boolean pauseFlag=false;   //暂停标记,true暂停态,false非暂停态
    MediaPlayer mp;                 //MediaPlayer引用
    AudioManager am;                //AudioManager引用
    @Override
    protected void onCreate(Bundle savedInstanceState) {//Activity创建时调用
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);                  //设置Activity的显示内容
        bPlay = (Button) findViewById(R.id.ButtonPlay);       //播放按钮的实例化
        bPause = (Button) findViewById(R.id.ButtonPause);     //暂停按钮的实例化
        bStop = (Button) findViewById(R.id.ButtonStop);       //停止音量按钮的实例化
        bAdd = (Button) findViewById(R.id.ButtonAdd);      //增大音量按钮的实例化
           bReduce = (Button) findViewById(R.id.ButtonReduce);   //降低音量按钮的实例化
           mp = new MediaPlayer();
           am = (AudioManager) this.getSystemService(this.AUDIO_SERVICE);
           bPlay.setOnClickListener(new View.OnClickListener() {//播放按钮的监听器
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                try {
                    mp.setDataSource("/sdcard/dl.mid");//加载音频进入Initialized状态
                } catch (IllegalArgumentException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (SecurityException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                try {
                    mp.prepare();                 //进入Prepared状态
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                mp.start();                        //播放音乐
                Toast.makeText(MyActivity.this, "播放音乐", Toast.LENGTH_SHORT).show();  
            }
        });
           bPause.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if(mp.isPlaying()){              //如果是在播放状态
                    mp.pause();                  //调用暂停方法
                    pauseFlag = true;            //设置暂停标记
                }else if(pauseFlag){
                    mp.start();                  //播放音乐
                    pauseFlag = false;           //设置暂停标记
                    Toast.makeText(MyActivity.this, "暂停播放", Toast.LENGTH_SHORT).show();
                }
            }
        });
           bStop.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mp.stop();                     //停止播放
                mp.reset();                    //重置状态到uninitialized状态
                try {
                    mp.setDataSource("/sdcard/dl.mid");       //加载音频进入Initialized状态
                } catch (IllegalArgumentException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (SecurityException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                try {
                    mp.prepare();                 //进入Prepared状态
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                Toast.makeText(MyActivity.this, "停止播放", Toast.LENGTH_SHORT).show();
            }
        });
           bAdd.setOnClickListener(new View.OnClickListener() {      //音量增大按钮添加监听器
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                am.adjustVolume(AudioManager.ADJUST_RAISE, 0);   //增大音量
                System.out.println("faaa");          
                Toast.makeText(MyActivity.this, "增大音量", Toast.LENGTH_SHORT).show();
            }
        });
           bReduce.setOnClickListener(new View.OnClickListener() {   //音量降低按钮添加监听器
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                am.adjustVolume(AudioManager.ADJUST_LOWER, 0);   //减小音量
                Toast.makeText(MyActivity.this, "减小音量", Toast.LENGTH_SHORT).show();
            }
        });
        
    }  

/*    @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;
    }
*/
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.sample3_2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/icon"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.sample3_2.MyActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

<?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="vertical" >
    <Button
        android:text="播放音乐"
        android:id="@+id/ButtonPlay"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">         
    </Button>                                <!-- 播放音乐按钮 -->   
    <Button
        android:text="暂停音乐"
        android:id="@+id/ButtonPause"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">     
    </Button>                                <!-- 暂停音乐按钮 -->
    <Button 
        android:text="停止音乐"
        android:id="@+id/ButtonStop"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">        
     </Button>                               <!-- 停止音乐按钮 -->
     <Button
         android:text="增大音乐"
         android:id="@+id/ButtonAdd"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"> 
      </Button>                              <!-- 增大音乐按钮 -->
      <Button
          android:text="降低音乐"
          android:id="@+id/ButtonReduce"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content">
      </Button>                              <!-- 降低音乐按钮 -->
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Sample3_2</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>

</resources>