How can we check signal strength either for mobile network or wifi in Xamarin forms app?

Question

What i want to achive is restrict user not to reach server when user do not have a stable internet or consider user as offline.

I tried to like get a connection type but did not success. Its crashing when we are trying to get typeNetworkInfo

Android Code:

public static bool IsConnectedFast(Context context)
{
     ConnectivityManager cm = (ConnectivityManager)context.GetSystemService(Context.ConnectivityService); 
     NetworkInfo info = cm.ActiveNetworkInfo;

     TelephonyManager tm = TelephonyManager.FromContext(context);
     return (info != null && info.IsConnected && NetworkConnectivity.IsConnectionFast(info.Type, tm.NetworkType)); // Getting crash here when trying with mobile connection
}