public sealed class GuiDispatcher : Control, 
	IDispatcher

Public NotInheritable Class GuiDispatcher
	Inherits Control
	Implements IDispatcher

public ref class GuiDispatcher sealed : public Control, 
	IDispatcher

[<SealedAttribute>]
type GuiDispatcher =  
    class
        inherit Control
        interface IDispatcher
    end

void Initialize()
{
    //Create a GUI dispatcher
    IDispatcher dispatcher = new GuiDispatcher();

    //The control will use dispatcher to synchronize threads
    SomeControl control = new SomeControl(dispatcher);
}

class SomeControl : UserControl
{
    private readonly IDispatcher dispatcher;

    public SomeControl(IDispatcher dispatcher)
    {
        this.dispatcher = dispatcher;
    }

    //This method can be called from non-GUI thread
    private void DrawTextInControl(string text)
    {
        if (dispatcher.SynchronizationRequired)
        {
            //Create a task that will be executed in dispatcher thread without blocking the calling thread
            dispatcher.Dispatch(new DelegateTask(delegate
            {
                this.Text = text;
            }));
        }
        else
        {
            //This is the GUI thread. 
            this.Text = text;
        }
    }
}