Как изменить цвет всех компонентов на форме в Run_time



Автор: Charles McNicoll
WEB-сайт: http://www.lmc-mediaagentur.de

I would like to change the font color on all components on a form at runtime (and the components owned by the components etc). I devised a recursive algorithm using RTTI that accepts a TComponent as a parameter. It works to some extent, but I still have to use 'if' statements to cast the object to a particular descendant, resulting in about 30 lines of code to test for all of the components I use. Also, some objects (TColumnTitle), are not descended from TComponent, even though they have a font property.

This may do the trick (with D6 and maybe D5):

uses
TypInfo;
{ ... }
var
i: integer;
aFont: TFont;
begin
for i := 0 to aComponent.ComponentCount - 1 do
begin
aFont := TFont(GetOrdProp(aComponent.Components[i], 'Font'));
if assigned(aFont) then
aFont.Color := clWhite;
end;
end;

With D4:

{ ... }
var
i: integer;
aFont: TFont;
pi: PPropInfo;
begin
for i := 0 to aComponent.ComponentCount - 1 do
begin
pi := GetPropInfo(aComponent.Components[i].ClassInfo, 'Font');
if assigned(pi) then
TFont(GetOrdProp(aComponent.Components[i], pi)).Color := clWhite;
end;
end;

Далее: Как определить, насдледовано ли свойство от определённого класса »»