Enter only Numeric Data in TextBox

private void TxtQuantity_KeyPress(object sender, KeyPressEventArgs e)

        {

if (char.IsDigit(e.KeyChar) == false && char.IsLetter(e.KeyChar) == false && char.IsControl(e.KeyChar) == false && e.KeyChar != '.' && e.KeyChar != ' ')

            {

                e.Handled = true;

                MessageBox.Show("You can enter only number.", "KenCloud", MessageBoxButtons.OK, MessageBoxIcon.Information);

                TxtQuantity.Clear();

                TxtQuantity.Focus();

                return;

            }

}