TextBox Event: KeyPress

TextBox just receive digit:

private void JustDigit_KeyPress(object sender, KeyPressEventArgs e)

        {

            const char Delete = (char)8;

            e.Handled = !Char.IsDigit(e.KeyChar) && e.KeyChar != Delete;

        }

TextBox just receive Alphabetic:

private void JustAlphabethic_KeyPress(object sender, KeyPressEventArgs e)
        {
            const char Delete = (char)8;
            e.Handled = !Char.IsLetter(e.KeyChar) && e.KeyChar != Delete;
        }

TextBox receive Alphabetic and Operation:

private void AlphabethicOperation_KeyPress(object sender, KeyPressEventArgs e)

        {

            e.Handled = char.IsDigit(e.KeyChar);
        }