Use AlignControls to align all controls within an area of the control bar. The alignment of child controls is based on their Align property. 

AControl is a child control that takes precedence in alignment over other, similarly-aligned controls. This parameter can be nil (Delphi) or NULL (C++). 

Rect specifies the area in which to align the controls. 

TCustomControlBar overrides the inherited method to enforce the alignment of child controls in a manner appropriate to a control bar. AlignControls determines the best alignment for each control according to its size and the available space.