InfinityGem.cs

        public int counter { get; set; }
        public async void test()
        {
            var uiThreadScheduler = TaskScheduler.FromCurrentSynchronizationContext();
            while(true)
            {
                
                Task backgroundTask = Task.Run (async () => {
                    await Task.Delay(300);
                    Interlocked.Increment(ref this.counter);
                });
                backgroundTask.ContinueWith(() => { textBox.Text = counter.ToString(); }, uiThreadScheduler);
            }
        }