if(Application.internetReachability == NetworkReachability.NotReachable) {
Debug.Log("当前网络不可用");
}else if(Application.internetReachability =NetworkReachability.ReachableViaCarrierDataNetwork)
{
Debug.Log("当前网络是4G或者3G");
}else if (Application.internetReachability == NetworkReachability.ReachableViaLocalAreaNetwork)
{
Debug.Log("当前网络是WIFI");
}