C# extension that helps async to callback main thread sync.

TaskSchedulerExtensions.cs

using System;
using System.Threading.Tasks;

namespace LuviKunG.Extensions
{
    public static class TaskSchedulerExtensions
    {
        public static Task ContinueWithCurrentSynchronizationContext(this Task task, Action<Task> action)
        {
            return task.ContinueWith(action, TaskScheduler.FromCurrentSynchronizationContext());
        }

        public static Task ContinueWithCurrentSynchronizationContext<T>(this Task<T> task, Action<Task<T>> action)
        {
            return task.ContinueWith(action, TaskScheduler.FromCurrentSynchronizationContext());
        }

        public static Task<T> ContinueWithCurrentSynchronizationContext<T>(this Task task, Func<Task, T> action)
        {
            return task.ContinueWith(action, TaskScheduler.FromCurrentSynchronizationContext());
        }

        public static Task<T> ContinueWithCurrentSynchronizationContext<T>(this Task<T> task, Func<Task, T> action)
        {
            return task.ContinueWith(action, TaskScheduler.FromCurrentSynchronizationContext());
        }
    }
}