AppDelegate.cs

using System.Net.Http.Headers;

namespace http_test;

[Register("AppDelegate")]
public class AppDelegate : UIApplicationDelegate
{
    public override UIWindow? Window
    {
        get;
        set;
    }

    public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
    {
        // create a new window instance based on the screen size
        Window = new UIWindow(UIScreen.MainScreen.Bounds);

        // create a UIViewController with a single UILabel
        var vc = new UIViewController();
        vc.View!.AddSubview(new UILabel(Window!.Frame)
        {
            BackgroundColor = UIColor.SystemBackground,
            TextAlignment = UITextAlignment.Center,
            Text = "Hello, iOS!",
            AutoresizingMask = UIViewAutoresizing.All,
        });
        Window.RootViewController = vc;

        // make the window visible
        Window.MakeKeyAndVisible();

        const int count = 100;
        var rnd = new Random ();
        var tasks = new Task[count];
        var str = new string ('z', 1024 * 1024 * 100); // 100 mb
        var content = new StringContent (str);
        for (var i = 0; i < count; i++) {
            tasks [i] = SendRequest(i, content, TimeSpan.FromSeconds (rnd.NextDouble () * 10));
        }
        Task.WaitAll (tasks);
        Console.WriteLine ("All done");

        return true;
    }

    HttpClient httpClient = new();

    async Task SendRequest(int id, HttpContent content, TimeSpan cancellationDelay)
    {
        try
        {
            var url = "https://httpbin.org/delay/10";
            Console.WriteLine ($"{id} Sending to {url}, waiting {cancellationDelay.TotalSeconds:#.##} s before cancelling");
            var requestMessage = new HttpRequestMessage (HttpMethod.Post, url) { Content = content };
            var token = new CancellationTokenSource ();
            var task = httpClient.SendAsync(requestMessage, token.Token).ConfigureAwait (false);
            var ignore = Task.Delay (cancellationDelay).ContinueWith (v =>
            {
                token.Cancel ();
            });
            var response = await task;
            if (response.IsSuccessStatusCode) {
                Console.WriteLine ($"{id} Success");
                return;
            }
            Console.WriteLine ($"{id} ❌ response failed: {response.StatusCode}");
            Console.WriteLine (await response.Content.ReadAsStringAsync().ConfigureAwait(false));
        } catch (TaskCanceledException e) {
            Console.WriteLine ($"{id} ⚠️ {e.Message}");
        } catch (Exception e) {
            Console.WriteLine ($"{id} ❌ {e.Message}");
            Console.WriteLine ($"{id} {e.StackTrace}");
        }
    }
}