Android BroadcastReceiver

先假设现在有MainActivity.java和NetworkAndroid.java这两个文件，要注册一个监听，监听网络的变化。

注册有两种方式：

1. (静态注册)

在Manifest.xml的application中

<receiver android:name=".NetWorkAndroid">

<intent-filter >

<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>

</intent-filter>

</receiver>

2.(动态注册)

在MainActivity.java中加入

private NetWorkAndroid mNetworkStateReceiver = null;

public void addNetworkObserver() {

if (null != mNetworkStateReceiver) {

return;

}

mNetworkStateReceiver = new NetWorkAndroid();

IntentFilter filter = new IntentFilter();

filter.addAction("android.net.conn.CONNECTIVITY_CHANGE");

this.registerReceiver(mNetworkStateReceiver, filter);

}

public void removeNetworkObserver() {

if (null == mNetworkStateReceiver) {

return;

}

this.unregisterReceiver(mNetworkStateReceiver);

mNetworkStateReceiver = null;

}

在需要注册的时候调用addNetworkObserver()，需要注销的时候调用removeNetworkObserver()

一般当检测到程序进入后台时，便需要注销，待程序回来后再注册，否则当程序被后台手动强制关闭后，网络产生变化，便会出现“unfortunatetly, xxx has stoped”

关于注册和注销的时机，如果是cocos2d-x游戏，建议在

void AppDelegate::applicationDidEnterBackground()

void AppDelegate::applicationWillEnterForeground()

其余情况，只要对称就好

例如

MainActivity.onStart()和MainActivity.onStop()

MainActivity.onResume和MainActivity.onPause()