Pixel in cm umrechnen

[Bummi]

Vielleicht hilft Dir das weiter?

http://www.swissdelphicenter.ch/de/showcode.php?id=1466

in Kurzform habe ich etwas derartigen in meiner Spickerkiste

Delphi-Quellcode:

procedure PaintRichedit(canvas:TCanvas;re:Trichedit;Bounds:Trect;pixelsperinch:Integer=96);

var fmt    : TFormatRange;
begin
    InflateRect(Bounds,-2,-2);
    Bounds.Left := Round(Bounds.Left * 1440 / pixelsperinch) ;
    Bounds.right := Round(Bounds.right * 1440 / pixelsperinch) ;
    Bounds.top := Round(Bounds.top * 1440 / pixelsperinch);
    Bounds.Bottom := Round(Bounds.Bottom * 1440 / pixelsperinch);
     with fmt do
     begin
          hdc:= Canvas.handle;
          hdcTarget:= hdc;
          chrg.cpMin := 0;
          rcPage := Bounds;
          rc := Bounds;
          chrg.cpMax := re.GetTextLen;
     end;
     SetBkMode( Canvas.Handle, TRANSPARENT );
     re.perform( EM_FORMATRANGE, 1, integer( @fmt ));
     re.perform( EM_FORMATRANGE, 0, 0 );
end;