Delphi 模拟网站验证码（酷，把随机文字写道图片上）

function TfrmLabelPages.PwdImg(img: Timage): string;
var
  I,j,k:   Integer;
  vPoint:   TPoint;
  vLeft:   Integer;
  arrStr:array [..]of string ;
  strResult: string;
begin
  strResult := '';
  arrStr[] := '';  arrStr[]:='';  arrStr[]:='';  arrStr[]:='';
  arrStr[] := '';  arrStr[]:='';  arrStr[]:='';  arrStr[]:='';
  arrStr[] := '';  arrStr[]:=''; arrStr[]:='A'; arrStr[]:='B';
  arrStr[] := 'C'; arrStr[]:='D'; arrStr[]:='E'; arrStr[]:='F';
  arrStr[] := 'G'; arrStr[]:='H'; arrStr[]:='I'; arrStr[]:='J';
  arrStr[] := 'K'; arrStr[]:='L'; arrStr[]:='M'; arrStr[]:='N';
  arrStr[] := 'O'; arrStr[]:='P'; arrStr[]:='Q'; arrStr[]:='R';
  arrStr[] := 'S'; arrStr[]:='T'; arrStr[]:='U'; arrStr[]:='V';
  arrStr[] := 'W'; arrStr[]:='X'; arrStr[]:='Y'; arrStr[]:='Z';
  For j:= to   do
  begin
    Randomize;
    k := strtoint(Format('%.1d',[Random()]));
    strResult := strResult + trim(arrStr[k])
  end;
  vLeft := ;
  img.picture := nil;
  for I :=  to Length(strResult) do
  begin
    with Img do
    begin
      Canvas.Font.Size := Random()+ ;
      Canvas.Font.Color := RGB(Random() and $C0,
      Random() and $C0, Random() and $C0);
      if Random()= then
        Canvas.Font.Style := [fsBold]
      else Canvas.Font.Style := [];
      begin
        Canvas.Font.Name := Screen.Fonts[];
        vPoint.X := Random()+ vLeft;
        vPoint.Y := Random();
        Canvas.TextOut(vPoint.X, vPoint.Y,strResult[I]);
        vLeft := vPoint.X + Canvas.TextWidth(strResult[I]);
      end;
    end;
  end;
end;  

http://blog.****.net/yanjiaye520/article/details/7957397