android 查看联网状态

ConnectivityManager cm =(ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

NetworkInfo netinfo = cm.getActiveNetworkInfo();

if (netinfo != null && netinfo.isConnected())

{
　　Log.i("NetStatus", "已经联上网络");

} else {
　　Log.i("NetStatus", "没有联上网络");
}