android 公開靜態內部類BroadcastReceiver

android 公開靜態內部類BroadcastReceiver

第一次寫部落格，寫得不好盼大家指正.

      當想實現廣播接收功能時，因java  是單繼承，所以一般一個類都會extends Activity，所以會想到內部類來extends BroadcastReceiver,這中間可能會出現兩種異常

1：java.lang.RuntimeException: Unable to instantiate 
     receiver com.example.progressbar.ProgressBarActivity$mBroadcastReceiver: 
     java.lang.InstantiationException: com.example.progressbar.ProgressBarActivity$mBroadcastReceiver

      這是因為內部類需要寫成靜態，即static 

static class mBroadcastReceiver extends BroadcastReceiver {
//必須為靜態公開的(public static)

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

2: java.lang.RuntimeException: Unable to instantiate 
    receiver com.example.progressbar.ProgressBarActivity$mBroadcastReceiver: 
    java.lang.IllegalAccessException: access to class not allowed

    這是因為需要將此類寫成public ，若沒寫預設為protected的，則會出現access to class not allowed

正確的為：

public static  class mBroadcastReceiver extends BroadcastReceiver {
 //必須為靜態公開的(public static)
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
}
}

內部類需要加上$

<receiver android:name="com.example.progressbar.ProgressBarActivity$mBroadcastReceiver" >
            <intent-filter>
                <action android:name="com.example.progressbar.ProgressBarActivity.mBroadcastReceiver" />
            </intent-filter>
        </receiver>

      當然還有另一種方法即實現其一個執行個體

private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {


        }
};

然後就是註冊和登出

在onCreate（） 或onResume（）中調用registerBoradcastReceiver()

public void registerBoradcastReceiver() {
IntentFilter myIntentFilter = new IntentFilter();
myIntentFilter.addAction(ACTION_NAME);
// 註冊廣播
registerReceiver(mBroadcastReceiver, myIntentFilter);
}

@Override
public void onDestroy() {
super.onDestroy();
unregisterReceiver(mBroadcastReceiver);
}