TDBGrid的组件编辑器双击后会调出Columns的属性编辑器，这要调用未公开的ColnEdit中的方法ShowCollectionEditorClass方法来实现，代码示意如下

uses ColnEdit，...；

....

procedure TSAGComponentEditor.ExecuteVerb(Index: Integer);
begin
case Index of
0://Show Column Editor;
begin
ShowCollectionEditorClass(Designer, TCollectionEditor, Component,
TSAGrid(Component).GridColumns, 'GridColumns', [coAdd, coDelete, coMove]);
end;
end;
end;