...die Abmessungen von sichtbaren Scrollbars ermitteln?

Autor: Duncan Parsons

Kategorie: VCL

{+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

when doing resizing operations, etc, sometimes you need a quick all
in one call to get how much room to allow for a scrollbar (which might
not even be there).

To help with iterating sets of controls, these functions have been
generalised to accept a TControl, which will just return 0 (since a
TGraphicControl descendant will not have a HWND; depending on your
control, you might want to alter this section if you have a
TGraphicControl descendent which implements a kind of scroller)

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++}


function GetScrollbarWidth(ctl: TControl): Integer;
begin
if
ctl is TWinControl then
begin
if
(GetWindowlong(TWinControl(Ctl).Handle, GWL_STYLE) and WS_VSCROLL) <> 0 then
Result := GetSystemMetrics(SM_CXVSCROLL)
else
Result := 0;
end
else
begin
Result := 0;
end;
end;

function GetScrollbarHeight(ctl: TControl): Integer;
begin
if
ctl is TWinControl then
begin
if
(GetWindowlong(TWinControl(Ctl).Handle, GWL_STYLE) and WS_HSCROLL) <> 0 then
Result := GetSystemMetrics(SM_CXHSCROLL)
else
Result := 0;
end
else
begin
Result := 0;
end;
end;

 

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