/// <summary> /// Extends BeginInvoke so that when a state object is not needed, null does not need to be passed. /// <example> /// toolstripdropdownclosedeventhandler.BeginInvoke(sender, e, callback); /// </example> /// </summary> public static IAsyncResult BeginInvoke(this ToolStripDropDownClosedEventHandler toolstripdropdownclosedeventhandler, Object sender, ToolStripDropDownClosedEventArgs e, AsyncCallback callback) { if (toolstripdropdownclosedeventhandler == null) { throw new ArgumentNullException("toolstripdropdownclosedeventhandler"); } return(toolstripdropdownclosedeventhandler.BeginInvoke(sender, e, callback, null)); }