Currency Formatting with Delphi

Question

I am trying to writte a code in Delphi, which will be displaying a given number in currency format like this:

Now it works if filled whole number and another field until any paramater is updated. I'd be happy to have a code which would displaying a number in currency format as I writte it. I've tried to manage it by typing this:

procedure TForm1.EditZakladChange(Sender: TObject);
var zaklad: Currency;
begin
  zaklad := StrToFloat(EditZaklad.Text);
  EditZaklad.Text := FloatToStrF(zaklad, ffCurrency, 10, 2);
end;

end.

But everytime when someting is typed in (zaklad field), this error appears:

Could somebody help me with that, please?

Answer 1

Make sure the MaxLength of edtZaklad is 0.

var
  Form21: TForm21;
  Check:string; //to break the loop.

function GetCurrency(Num: String):string;
var
  i: Integer ;
  Str:String;
  zaklad: Currency;
begin
  Result := '';
  for i := 1 to length(Num) do
  begin
    if (Num[i] in ['0'..'9']) then
    Begin
      Str := Str + Num[i] ;
      zaklad := StrToFloat(Str);
      Result := FloatToStrF(zaklad, ffCurrency, 10, 2);
      Check := Result;
    End;
  end;
end;

function ExtractCurrencySymbol(zaklad: String):string;
var
  i: Integer ;
  Str:String;
begin
  Result := '';
  for i := 1 to length(zaklad) do
  begin
    if NOT (zaklad[i] in ['0'..'9','.',',']) then
    Begin
      Str := Str + zaklad[i];
      Result := ' '+Trim(Str);
  end;
  end;

end;

procedure TForm21.EditZakladChange(Sender: TObject);
begin
  if AnsiPos(Check,EditZaklad.Text) <> 0 then exit;
  if (Trim(EditZaklad.Text) = '') then exit
  else
  begin
    EditZaklad.Text := GetCurrency(EditZaklad.Text)+ExtractCurrencySymbol(EditZaklad.Text);
    Exit;
  end;
end;

I hope this what you asked for.