ColorToDec function (clRed = $0000FF)?

Question

How do you convert a TColor value to a decimal representation (clRed = $0000FF)?

Answer 1

Try

function FromTColorDelphiToHex(Color : TColor) : string;
begin
   Result :='$'+
     IntToHex(GetBValue(Color), 2) +
     IntToHex(GetGValue(Color), 2) +
     IntToHex(GetRValue(Color), 2) ;
end;

Answer 2

Try this:

uses
   Graphics;

function ColorToHex(const color: TColor): string;
begin
   result := '$' + IntToHex(ColorToRGB(color), 6);
end;

Answer 3

after several hours I came up with this.

function ColorToDecimal( Color: TColor ): string;
var
  AColor: integer;
  DecimalColor: integer;
begin
  DecimalColor := ColorToRGB( Color );
  FmtStr( Result, '%s%0.8x', [ HexDisplayPrefix, DecimalColor ] );
end;

I think it works but still testing...

Answer 4

I've always been a fan of "Format" for such uses:

function ColorToHex(color: TColor): String;
begin
   Result := Format('$%.6x', [integer(aColor)]);
end;

Answer 5

Colour constants in Delphi (and the Windows API) are simply signed integers. They are normally represented in Hexadecimal format (with a leading $).

It is defined in Graphics.pas as TColor = -$7FFFFFFF-1..$7FFFFFFF;

Positive values ($00000000 -> $00FFFFFF) are in BGR format: $00FF0000 = blue, $0000FF00 = green, $000000FF = red.

Negative values refer to user defineable system colours, like the colour for window text (clWindowText).

To convert a TColor to it's display value, use

IntToHex(Colour, 8);

or use

Format('%.8x', [Colour]);

In older versions of Delphi, IntToHex calls Format(), in later versions it is directly implemented and is much faster.

To convert to HTML #RRBBGG format, you need to reverse the red and green values in RRUZ answer:

function FromTColorDelphiToHTML(Color : TColor) : string;
begin
   Result :='#'+
     IntToHex(GetRValue(Color), 2) +
     IntToHex(GetGValue(Color), 2) +
     IntToHex(GetBValue(Color), 2) ;
end;