How do I make a textbox that only accepts numbers?

How do I make a textbox that only accepts numbers?

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)

{

    if (!char.IsControl(e.KeyChar)

        && !char.IsDigit(e.KeyChar)

        && e.KeyChar != '.')

    {

        e.Handled = true;

    }

    // only allow one decimal point

    if (e.KeyChar == '.'

        && (sender as TextBox).Text.IndexOf('.') > -1)

    {

        e.Handled = true;

    }

}

Or use this 

private void textBox1_TextChanged(object sender, EventArgs e)

    {

        if (System.Text.RegularExpressions.Regex.IsMatch("[^0-9]", textBox1.Text))

        {

            MessageBox.Show("Please enter only numbers.");

            textBox1.Text.Remove(textBox1.Text.Length - 1);

        }

    }