Cote de Azur

When performing any action on a control which requires the updating of a user interface element (e.g. setting the Text property on almost any class derived from Control, updating the data source behind a DataGrid), these operations MUST take place on the thread that created the UI element.

In order to do this, the Control class provides the Invoke method, which will take a delegate and execute it on the thread that the UI element was created on. In order to use this, one must declare a function that performs the UI operation. For example, say a form has a TextBox on it named m_TextBox. To update the text from another thread, create a method that will update the Text property on the TextBox:

Refer to the System.Threading namespace on MSDN for full details. Meanwhile here is a quick taste.

using System;
using System.Threading; 

class ThreadTest
{
    public void Runme()
    {
        Console.WriteLine("Runme Called");
        Thread.Sleep(10000);
    }

    public static void Main(String[] args)
    {
        ThreadTest b = new ThreadTest();
        Thread t = new Thread(new ThreadStart(b.Runme));
        t.Start(); 

        Console.WriteLine("Thread 't' started.");
        Console.WriteLine("There is no telling when " + 
                          "'Runme' will be invoked. "); 

        t.Join(); 

        Console.WriteLine("Thread 't' has ended.");
    }
}