Code:

unit Todrmemo;

interface

uses

SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,

Forms, Dialogs, StdCtrls;

type

TOwnerDrawMemo = class(TMemo)

private

   { Private declarations }

   procedure WMPaint(var Message: TWMPaint); message WM_PAINT;

protected

   { Protected declarations }

public

   { Public declarations }

published

   { Published declarations }

end;

procedure Register;

implementation

procedure TOwnerDrawMemo.WMPaint(var Message: TWMPaint);

var

Buffer: array[0..255] of Char;

PS: TPaintStruct;

DC: HDC;

i: Integer;

X, Y, Z: Word;

OldColor: LongInt;

begin

DC := Message.DC;

if DC = 0 then

   DC := BeginPaint(Handle, PS);

try

   X := 1;

   Y := 1;

   SetBkColor(DC, Color);

   SetBkMode(DC, Transparent);

   OldColor := Font.Color;

   for i := 0 to Pred(Lines.Count) do

   begin

     if odd(i) then

       SetTextColor(DC, clRed)

     else

       SetTextColor(DC, OldColor);

     Z := Length(Lines[i]);

     StrPCopy(Buffer, Lines[i]);

     Buffer[Z] := #0; { реально не нужно }

     TextOut(DC, X, Y, Buffer, Z);

     Inc(Y, abs(Font.Height));

   end;

finally

   if Message.DC = 0 then

     EndPaint(Handle, PS);

end;

end;

procedure Register;

begin

RegisterComponents('Dr.Bob', [TOwnerDrawMemo]);

end;

end.