Returns or sets how the panel can be sized. Fixed - The panel's size is controlled by the width. Automatic - The panel's size is based on its contents. Adjustable - The panel's base size is controlled by the width but the panel may be resized. Spring - The panel size is based on the remaining size remaining after the other visible panes have been sized.

PanelSizingMode SizingMode {get; set;}

property PanelSizingMode SizingMode {
   PanelSizingMode get();
   void set (    PanelSizingMode value);
}