TDBEditEh无法用方向键移动焦点？ ( 积分: 20 )

procedure TForm1.FormCreate(Sender: TObject);
begin
KeyPreview := True;
end;

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
case Key of
VK_DOWN: if ActiveControl is TDBEditEh then Perform(WM_NEXTDLGCTL, 0, 0);
VK_UP: if ActiveControl is TDBEditEh then Perform(WM_NEXTDLGCTL, 1, 0);
end;
end;
其它的控件都可以用方向键传递，上面这样指明TDBEditEh也不行

wnetaddconnection2(netsource,'','administrator',CONNECT_UPDATE_PROFILE);