using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace UseAwait
{
	public partial class Form1 : Form
	{
		public Form1()
		{
			InitializeComponent();
		}

		private async void RunIt()
		{
			Task<double> task = Task<double>.Factory.StartNew(() => LongCalc(5));

			// not block the UI thread
			await task;

			progressText.Text = task.Result.ToString();
		}

		private double LongCalc(double r)
		{
			Thread.Sleep(3000);

			return Math.PI * r * r;
		}

		private void syncButton_Click(object sender, EventArgs e)
		{
			Task<double> task = Task<double>.Factory.StartNew(() => LongCalc(5));

			task.Wait();

			progressText.Text = task.Result.ToString();
		}

		private void asyncButton_Click(object sender, EventArgs e)
		{
			RunIt();
		}
	}
}