TForm1.Edit1KeyPress     // For Number

DecimalSeparator := '.'; // or DecimalSeparator := ',';

Edit1.MaxLength := 3; // Max Length = 3

// Float

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);

begin

    test := (Sender as TEdit).Text;
    deci := AnsiPos('.',test);

    case key of

    #44,#46 : if deci = 0  then
                    Begin
                        key := '.';
                        deci :=1;
                    end
                else key := #0;

     else if not (key in [#8,'0'.. '9']) // #8 = Back Space
        then key := #0;

     end;

end;

// Integer

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);

begin

if not (key in [#8,'0'.. '9'])   //#8 = Back Space
   then key := #0;

end;