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--- 字符串，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文件中靜態注冊是無效的 <receiver android:name=".HeadsetPlugReceiver"> <intent-filter> <action android:name="android.intent.action.HEADSET_PLUG" android:enabled="true"> </action> </intent-filter> </receiver> 解決辦法是在代碼中動態注冊。

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(); //注銷監聽 } private void unregisterReceiver(){ this.unregisterReceiver(headsetPlugReceiver); } }

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 { @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(); } } } }