Rob Kennedy wrote:
>If you have a TColor value, and you need to use it as a TColorRef, then
> always use the ColorToRGB function. Nothing in the Windows API uses
> TColor. The GetRValue, GetBValue, and GetGValue functions are part of
> the API.
So the following code :
var Red, Green, Blue:integer;
begin
Red:=GetRValue( ColorToRGB(clBtnFace));
Green:=GetGValue( ColorToRGB(clBtnFace));
Blue:=GetBValue( ColorToRGB(clBtnFace));
Is equivalent to or much better than the following code, right?
type
TRGB = record
R: Integer;
G: Integer;
B: Integer;
end;
function RGBToColor(PR,PG,PB: Integer): TColor;
begin
Result := TColor((PB * 65536) + (PG * 256) + PR);
end;
function ColorToRGB(PColor: TColor): TRGB;
var
i: Integer;
begin
i := PColor;
Result.R := 0;
Result.G := 0;
Result.B := 0;
while i - 65536 >= 0 do begin i := i -
65536; Result.B := Result.B + 1; end;
while i - 256 >= 0 do begin i := i -
256; Result.G := Result.G + 1; end;
Result.R := i;
end;
function RGBToCol(PRGB: TRGB): TColor;
begin
Result := RGBToColor(PRGB.R,PRGB.G,PRGB.B);
end;
Now, you can write;
var RGB:TRGB ;
begin
RGB:=ColorToRGB(clBtnFace);
Monir.
----- Original Message -----
From: "Rob Kennedy" <[EMAIL PROTECTED]>
To: "Delphi-Talk Discussion List" <[email protected]>
Sent: Monday, March 14, 2005 2:00 AM
Subject: Re: system colours
> Monir-SCS wrote:
> >> Have a look at the ColorToRGB() function from the Graphics unit.
> >
> > This one works only with system color, right?
>
> If you pass is a system color, like clBtnFace or clWindow, then it will
> return the actual color. If you pass it a normal color, like clRed or
> clGreen, then it will return the original color. As I recall, ColorToRGB
> will not work on palette colors (in part because the function doesn't
> know what palette you're using).
>
> If you have a TColor value, and you need to use it as a TColorRef, then
> always use the ColorToRGB function. Nothing in the Windows API uses
> TColor. The GetRValue, GetBValue, and GetGValue functions are part of
> the API.
>
> --
> Rob
>
> __________________________________________________
> Delphi-Talk mailing list -> [email protected]
> http://www.elists.org/mailman/listinfo/delphi-talk
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