android-檢測耳機的插入和拔出動作

在android系統中，檢測耳機的插入和拔出，也是通過廣播實現的，可以建立一個Broadcast Receiver 監聽"android.intent.action.HEADSET_PLUG" 這個Intent。

在這個Intent中包含以下幾個值：

• state ---      
  0代表拔出，1代表插入
• name--- 字串，代表headset的類型。
• microphone --   1代表這個headset有麥克風，0則沒有。

在使用的時候發現直接在AndroidManifest,xml檔案中靜態註冊是無效的<receiver android:name=".HeadsetPlugReceiver"><br /> <intent-filter><br /> <action android:name="android.intent.action.HEADSET_PLUG" android:enabled="true"> </action><br /> </intent-filter><br /> </receiver> 解決辦法是在代碼中動態註冊。import android.app.Activity;<br />import android.content.IntentFilter;<br />import android.os.Bundle;</p><p>public class HeadSetActivity extends Activity {<br />HeadsetPlugReceiver headsetPlugReceiver;<br /> /** Called when the activity is first created. */<br /> @Override<br /> public void onCreate(Bundle savedInstanceState) {<br /> super.onCreate(savedInstanceState);<br /> setContentView(R.layout.main);<br /> registerHeadsetPlugReceiver();<br /> }<br /> private void registerHeadsetPlugReceiver(){<br /> headsetPlugReceiver = new HeadsetPlugReceiver ();<br /> IntentFilter filter = new IntentFilter();<br /> filter.addAction("android.intent.action.HEADSET_PLUG");<br /> registerReceiver(headsetPlugReceiver, filter);<br /> }<br />@Override<br />protected void onDestroy() {<br />// TODO Auto-generated method stub<br />super.onDestroy();<br />unregisterReceiver(); //登出監聽<br />}<br />private void unregisterReceiver(){<br />this.unregisterReceiver(headsetPlugReceiver);<br />}<br />}

在broadcast Receiver中監聽事件：

<pre name="code" class="java">import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class HeadsetPlugReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubif(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();}}}}</pre><p>