当想实现广播接收功能时，因java  是单继承，所以一般一个类都会extends Activity，所以会想到内部类来extends BroadcastReceiver,这中间可能会出现两种异常

1：java.lang.RuntimeException: Unable to instantiate

receiver com.example.progressbar.ProgressBarActivity$mBroadcastReceiver:

java.lang.InstantiationException: com.example.progressbar.ProgressBarActivity$mBroadcastReceiver

这是因为内部类需要写成静态的，即static

static class mBroadcastReceiver extends BroadcastReceiver {

//必须为静态公开的(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

这是因为需要将此类写成public ，若没写默认为protected的，则会出现access to class not allowed

正确的为：

public static class mBroadcastReceiver extends BroadcastReceiver {

//必须为静态公开的(public static)

@Override

public void onReceive(Context context, Intent intent) {

// TODO Auto-generated method stub

}

}

内部类需要加上$

当然还有另一种方法即实现其一个实例

private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {

@Override

public void onReceive(Context context, Intent intent) {

}

};

然后就是注册和注销

在onCreate() 或onResume()中调用registerBoradcastReceiver()

public void registerBoradcastReceiver() {

IntentFilter myIntentFilter = new IntentFilter();

myIntentFilter.addAction(ACTION_NAME);

// 注册广播

registerReceiver(mBroadcastReceiver, myIntentFilter);

}

@Override

public void onDestroy() {

super.onDestroy();

unregisterReceiver(mBroadcastReceiver);

}