BroadcastReceiver&&IntentFilter&&NetWorkChangeState

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

动态注册广播–程序active状态

private IntentFilter intentFilter;
private NetWorkChangeReceiver netWorkChangeReceiver;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
intentFilter = new IntentFilter();
intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
netWorkChangeReceiver = new NetWorkChangeReceiver();
registerReceiver(netWorkChangeReceiver,intentFilter);

}

@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(netWorkChangeReceiver);
}

class NetWorkChangeReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "networkchange", Toast.LENGTH_SHORT).show();

ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isAvailable()){
Toast.makeText(context,"net is available",Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(context,"net is unavailable",Toast.LENGTH_SHORT).show();
}
}
}

静态注册广播 –程序unactive状态