HandleOnce

/// <summary>
/// Creates a wrapper for the given event handler which unsubscribes from the event source immediately prior to calling the given event handler.
/// </summary>
/// <param name="handler">Handler that will be wrapped.</param>
/// <param name="remove">Action to remove the wrapped handler. (wrapper =&gt; source.MyEvent -= wrapper);</param>
/// <returns></returns>
/// <example>
/// <code>
/// source.TestEvent += new EventHandler(source_TestEvent)
///		.HandleOnce(wrapper => source.TestEvent -= wrapper);
///	</code>
/// </example>
public static EventHandler HandleOnce(this EventHandler handler, Action<EventHandler> remove)
{
	EventHandler wrapper = null;
	wrapper = delegate(object sender, EventArgs e)
	{
		remove(wrapper);
		handler(sender, e);
	};
	return wrapper;
}

source.TestEvent += new EventHandler(source_TestEvent)
.HandleOnce(wrapper => source.TestEvent -= wrapper);