C# Illegal Cross Thread Operation Problem Solution

In Visual Studio, using .NET Framework,
if you are trying to access a user interface control, in multi thread operation, you may get this error Illegal Cross Thread Operation .

That is the thread other than the thread it was created on has no access to change the control interface properties.
To avoid the Illegal Cross Thread Operation error here is the solution;

• Make a delegate for the control which you want update in multi threading.
• Check if needs InvokeRequired.
• Invoke the control, then it will invoke ones again, by its creator object.
• Second time the control invokes, set its properties as you wish.

The Following C# sample code shows all these steps.

public delegate void UpdateMeLabel(string _str, Color _fontcolor);
public void FormTxtUpdate(string str, Color fontcolor)
{
if (this.label1.InvokeRequired)
{
 UpdateMeLabel updaterdelegate = new UpdateMeLabel(FormTxtUpdate);
 this.Invoke(updaterdelegate , new object[] { str, fontcolor });
}
else
{
 label1.Text = str;
 label1.ForeColor = fontcolor;
}

} 

By this way, we update the control label1, its text and color values. For example call FormTxtUpdate("Hello World", Color.Red) in multi thread operation, Then label1 text will set to "Hello World" and its color set to Red.