interview_questions_ios

using System;
using System.Threading.Tasks;
using UIKit;

namespace interview_questions_ios
{
    public partial class ViewController : UIViewController
    {
        public ViewController(IntPtr handle) : base(handle)
        {
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();

            var button = new UIButton(UIButtonType.System)
            {
                Frame = new CoreGraphics.CGRect(100, 10, 200, 100)
            };

            button.SetTitle("Load data", UIControlState.Normal);

            button.TouchUpInside += (sender, e) =>
            {
                var data = LoadDataAsync().Result;

                button.SetTitle(data, UIControlState.Normal);
            };

            var button2 = new UIButton(UIButtonType.System)
            {
                Frame = new CoreGraphics.CGRect(100, 110, 200, 100)
            };

            button2.SetTitle("Load data 2", UIControlState.Normal);

            button2.TouchUpInside += async (sender, e) =>
            {
                var data = await LoadDataAsync().ConfigureAwait(false);

                button2.SetTitle(data, UIControlState.Normal);
            };

            var button3 = new UIButton(UIButtonType.System)
            {
                Frame = new CoreGraphics.CGRect(100, 210, 200, 100)
            };

            button3.SetTitle("Load data 3", UIControlState.Normal);

            button3.TouchUpInside += async (sender, e) =>
            {
                var data1 = await LoadDataAsync();
                var data2 = await LoadDataAsync();
                var data3 = await LoadDataAsync();

                var data = data1 + data2 + data3;

                button3.SetTitle(data, UIControlState.Normal);
            };

            View.AddSubview(button);
            View.AddSubview(button2);
            View.AddSubview(button3);
        }

        async Task<string> LoadDataAsync()
        {
            await Task.Delay(1000);
            return "42";
        }
    }
}