android-检测耳机的插入和拔出动作

在android系统中，检测耳机的插入和拔出，也是通过广播实现的，可以建立一个Broadcast Receiver 监听"android.intent.action.HEADSET_PLUG" 这个Intent。

在这个Intent中包含以下几个值：

• state ---        0代表拔出，1代表插入
• name--- 字符串，代表headset的类型。
• microphone --   1代表这个headset有麦克风，0则没有。

在使用的时候发现直接在AndroidManifest,xml文件中静态注册是无效的

 <receiver android:name=".HeadsetPlugReceiver">
         <intent-filter>
           <action android:name="android.intent.action.HEADSET_PLUG" android:enabled="true">           action>
         intent-filter>
   receiver>

解决办法是在代码中动态注册。

 import android.app.Activity;
 import android.content.IntentFilter;
 import android.os.Bundle;

 public class HeadSetActivity extends Activity {
     HeadsetPlugReceiver headsetPlugReceiver;
     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         registerHeadsetPlugReceiver();
     }
     private void registerHeadsetPlugReceiver(){
         headsetPlugReceiver  = new HeadsetPlugReceiver ();
         IntentFilter  filter = new IntentFilter();
         filter.addAction("android.intent.action.HEADSET_PLUG");
         registerReceiver(headsetPlugReceiver, filter);
     }
 @Override
 protected void onDestroy() {
     // TODO Auto-generated method stub
     super.onDestroy();
     unregisterReceiver();  //注销监听
 }
 private void unregisterReceiver(){
     this.unregisterReceiver(headsetPlugReceiver);
 }
 }

在broadcast Receiver中监听事件：

 "code" class="java">
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.widget.Toast;

 public class HeadsetPlugReceiver extends BroadcastReceiver {

     @Override
     public void onReceive(Context context, Intent intent) {
         // TODO Auto-generated method stub

             if(intent.hasExtra("state")){
                 if(intent.getIntExtra("state", 0)==0){
                     Toast.makeText(context, "headset not connected", Toast.LENGTH_LONG).show();
                 }
                 else if(intent.getIntExtra("state", 0)==1){
                     Toast.makeText(context, "headset  connected", Toast.LENGTH_LONG).show();
                 }
             }
     }

 }