Xamarin.Forms application throws NullReferenceException only in iOS

Question

I'm creating a Xamarin.Forms Portable application that runs fine in Android but always crashes in iOS.

I get this error:

System.NullReferenceException: Object reference not set to an instance of an object at App.ListJson+<GetPodcasts>d__2.MoveNext () [0x0004e]

It occurs at this piece of code, on the second line:

var httpClient = new HttpClient();
var json = await httpClient.GetStringAsync(REDACTEDSTRING).ConfigureAwait(false);

I've tried fiddling with the HttpClient implementation settings for the iOS project but still get the same error.

I would assume you using a non-secure URL on iOS and have not white-listed it... — SushiHangover
– SushiHangover, Commented Dec 16, 2016 at 0:06
What would constitute as non-secure? I am using an HTTPS url on a server with TLS 1.2 and GlobalSign verification. — Brendan McCoy
– Brendan McCoy, Commented Dec 16, 2016 at 0:14
I assumed wrong (http://), but since you are using TLS 1.2, are you using a native IOS HttpClient and Apple's TLS (both assigned in iOS Build options). Also whats the reasoning to using ConfigureAwaiting.. — SushiHangover
– SushiHangover, Commented Dec 16, 2016 at 0:32
I eventually stumbled upon a solution from another question, after sifting through at least 30 threads :P. The ConfigureAwait is from the code samples I've been learning from (I'm new to C#). — Brendan McCoy
– Brendan McCoy, Commented Dec 16, 2016 at 0:46

Community · Accepted Answer · 2017-05-23 12:33:54Z

0

The answer found here solved my problem.

To reiterate it here:

Installing the Microsoft.Net.Http NuGet package into the base project will fix the issue.

CommunityBot

11 silver badge

answered Dec 16, 2016 at 0:44

Brendan McCoy

801 silver badge6 bronze badges

Sign up to request clarification or add additional context in comments.

1 Answer 1