[android]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(100);
 registerReceiver(mediaButtonReceiver, intentFilter);

 

（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);