Xamarin Forms: ModernHttpClient errorhandling in PCL - exception

Question

My app connects to an api which requires an HTTPS-connection.
ModernHttpClients (NativeMessageHandler) works fine until an exception is thrown...
When there is no wifi available, an UnknownHostException is thrown on Android. Is it possible to make a catch that works on both Android and iOS? UnknownHostException is in the Java.Net library which can't be used in the iOS project.

Answer 1

You can use Xam.Plugin.Connectivity NuGet Package to Check Network Connectivity In Xamarin.Forms using following code
if (CrossConnectivity.Current.IsConnected) {
// your logic...
} else {
// write your code if there is no Internet available
}
OR
Refer http://www.c-sharpcorner.com/blogs/how-to-check-network-connectivity-in-xamarinforms

Answer 2

You can use the ConnectivityPlugin in your shared Xamarin Forms code to check for an internet connection before doing your request.

Answer 3

Personally I'm using a cross platform interface to handle network errors. You can for instance have something like (using MvvmCross in this example):
try
{
var client = new HttpClient();
var result = await client.GetAsync("http://some-url.com");
}
catch (Exception e)
{
var platformErrorChecker = Mvx.Resolve<IPlatformNetworkError>();
if (platformErrorChecker.IsNetworkError(e))
{
// Handle network error
}
else
{
// Other exception, just throw
throw;
}
}
And a service defined as:
public interface IPlatformNetworkError
{
bool IsNetworkError(Exception e);
}
Which you implement on each platform specifically, or only where needed. This is a simple example of course, you can have each platform provide more information about their specific network errors.