Threading and UI

Calculations.cs

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace AsynchTask
{
    public class frmCalculations : System.Windows.Forms.Form
    {
        Task Task1;
        private System.Windows.Forms.Label lblRunLoops;
        private System.Windows.Forms.Button btnRunLoops;
        private System.Windows.Forms.TextBox txtValue;
        private System.Windows.Forms.Label label1;
        private System.ComponentModel.Container components = null;

        public frmCalculations()
        {
            InitializeComponent();

            Task1 = new Task();
            Task1.LoopComplete += new Task.LoopCompleteHandler(this.LoopDoneHandler);
        }

        // ..Windows Form Designer generated code.. //

        [STAThread]
        static void Main()
        {
            Application.Run(new frmCalculations());
        }

        private void btnRunLoops_Click(object sender, System.EventArgs e)
        {
            try
            {
                Task1.varLoopValue = int.Parse(txtValue.Text);
            }
            catch(FormatException)
            {
                MessageBox.Show("Enter that must be numeric.");
            }
            btnRunLoops.Enabled = false;
            lblRunLoops.Text = "Looping

";

            Task1.StartTask();
        }

        protected void LoopDoneHandler(double Calculations, int Count)
        {
            lblRunLoops.Text = Count.ToString();
            btnRunLoops.Enabled = true;
        }

    }
}

Task.cs

using System;
using System.Threading;

namespace AsynchTask
{
    // The Task object encapsulates functionality known to be somewhat time consuming.
    public class Task
    {
        public int varLoopValue;
        public double varTotalCalculations = 0;

        public Thread LoopThread;

        public Task(){}

        // Delegates for events that your component will use to communicate values to the form
        public delegate void LoopCompleteHandler(double TotalCalculations, int Counter);

        // events that this (class)component will use to communicate with the app
        public event LoopCompleteHandler LoopComplete;

        public void RunALoop()
        {
            int varX;
            double varTotalAsOfNow = 0;

            // simulate a lengthy operation
            for(varX=1; varX <= varLoopValue; varX++)
            {
                for (int varY=1; varY <= 500; varY++)
                {
                    varTotalCalculations += 1;
                    varTotalAsOfNow = varTotalCalculations;
                }
            }

            // determine if the object on which this delegate was invoked is a UI thread
            // if the object is a control, then the object is a UI thread
            if (LoopComplete.Target is System.Windows.Forms.Control)
            {
                // make sure execution is done on the UI thread
                System.Windows.Forms.Control t = LoopComplete.Target as System.Windows.Forms.Control;
                if (t != null)
                {
                    t.BeginInvoke(LoopComplete, new Object[]{varTotalAsOfNow, varLoopValue});
                }
            }
            else
            {
                // object from the invocation list isn't a UI thread.
                LoopComplete(varTotalAsOfNow, varLoopValue);
            }
        }

        public void StartTask()
        {
            LoopThread = new Thread(new ThreadStart(this.RunALoop));
            LoopThread.Start();
        }

    }
}