Gets or sets whether a zone can enlarge its size to contain a docking panel.
true to allow a zone to grow; otherwise, false
A DockPanel can enlarge its size (Height for a vertically oriented zone and Width for a horizontally oriented zone) to contain a docking panel. Set the AllowGrowing property to false, to prohibit a zone from growing. In this case, a panel cannot be docked in the zone if it does not fit.