Call DeleteSelection to remove the selected components in the designer and free their memory. 

ADoAll controls what objects are freed. When ADoAll is false, components are only freed if the deletion can be undone. When ADoAll is true, all components are deleted, including any components that can't be recovered by an Undo operation. 

To remove the components from the set of selected components without deleting them, use SetSelections instead. To delete the contents of the components but not the components themselves, use ClearSelection instead. 

GetSelections 

SetSelections 

CutSelection 

ClearSelection