public void AddTimelineToolbox( ) { TimelineToolbox toolbox; RowDefinition rd; toolbox = new TimelineToolbox(); toolbox.SetSite(this as ITimelineToolboxTarget); rd = new RowDefinition(); if (toolbox.DesiredSize.Height > 0) { rd.Height = new GridLength(toolbox.DesiredSize.Height); } else { rd.Height = new GridLength(0, GridUnitType.Auto); } this.RowDefinitions.Add(rd); toolbox.SetValue(Grid.RowProperty, this.RowDefinitions.Count() - 1); this.Children.Add(toolbox); }