使用线控耳机来操控应用功能

 

使用线控耳机来操控应用功能

 

 

实现原理：通过广播拦截来实现。

 

（一）定义1个广播拦截器，用来拦截线控耳机按键产生的广播事件。

 

import android.content.BroadcastReceiver;  
import android.content.Context;  
import android.content.Intent;  
import android.os.Bundle;  
import android.os.Handler;  
import android.os.Message;  
import android.util.Log;  
import android.view.KeyEvent;  
  
public class MediaButtonReceiver extends BroadcastReceiver {  
      
    /** 
     * Handler 
     */  
    private Handler handler;  
      
    /** 
     * 构造器. 
     * @param handler 
     */  
    public MediaButtonReceiver(Handler handler) {  
        this.handler = handler;  
    }  
  
    @Override  
    public void onReceive(Context context, Intent intent) {  
        boolean isActionMediaButton = Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction());  
        if(!isActionMediaButton) return;  
        KeyEvent event = (KeyEvent)intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);  
        if(event==null) return;  
          
        boolean isActionUp = (event.getAction()==KeyEvent.ACTION_UP);  
        if(!isActionUp) return;  
          
        int keyCode = event.getKeyCode();  
        long eventTime = event.getEventTime()-event.getDownTime();//按键按下到松开的时长  
        Message msg = Message.obtain();  
        msg.what = 100;  
        Bundle data = new Bundle();  
        data.putInt("key_code", keyCode);  
        data.putLong("event_time", eventTime);  
        msg.setData(data);  
        handler.sendMessage(msg);  
          
        //终止广播(不让别的程序收到此广播，免受干扰)  
        abortBroadcast();  
    }  
}  

 

 

（二）在主程序的处理：

 

（1）定义并注册广播服务

 

//初始化Handler对象  
MyHandler handler = new MyHandler();  
//初始化媒体(耳机)广播对象.  
MediaButtonReceiver mediaButtonReceiver = new MediaButtonReceiver(handler);  
//注册媒体(耳机)广播对象  
IntentFilter intentFilter = new IntentFilter(Intent.ACTION_MEDIA_BUTTON);  
intentFilter.setPriority(10000);  
registerReceiver(mediaButtonReceiver, intentFilter);  

 

 

也可以这样注册广播：

<receiver android:name="MediaButtonReceiver">
		    <intent-filter android:priority="10000">
		         <action android:name="android.intent.action.MEDIA_BUTTON" />
		    </intent-filter>
		</receiver>

 

 

（2）定义MyHandler和处理广播发回的消息：

 

private class MyHandler extends Handler{  
    @Override  
    public void handleMessage(Message msg) {  
        int what = msg.what;  
        switch(what){  
        case 100://单击按键广播  
            Bundle data = msg.getData();  
            //按键值  
            int keyCode = data.getInt("key_code");  
            //按键时长  
            long eventTime = data.getLong("event_time");  
            //设置超过2000毫秒，就触发长按事件  
            boolean isLongPress = (eventTime>2000);  
              
            switch(keyCode){  
            case KeyEvent.KEYCODE_HEADSETHOOK://播放或暂停  
            case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE://播放或暂停  
                playOrPause();  
                break;  
                  
            //短按=播放下一首音乐，长按=当前音乐快进  
            case KeyEvent.KEYCODE_MEDIA_NEXT:  
                if(isLongPress){  
                    fastNext(1);//自定义  
                }else{  
                    playNext();//自定义  
                }  
                break;  
                  
            //短按=播放上一首音乐，长按=当前音乐快退    
            case KeyEvent.KEYCODE_MEDIA_PREVIOUS:  
                if(isLongPress){  
                    fastPrevious(1);//自定义  
                }else{  
                    playPrevious();//自定义  
                }  
                break;  
            }  
              
            break;  
        default://其他消息-则扔回上层处理  
            super.handleMessage(msg);  
        }  
    }  
}  

 

（3）应用程序退出的时候，别忘了取消注册的广播拦截器。

unregisterReceiver(mediaButtonReceiver);