c# form textbox only numbers code example

Example: check textbox is only numbers + c#

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    // Verify that the pressed key isn't CTRL or any non-numeric digit
    if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != '.'))
    {
        e.Handled = true;
    }

    // If you want, you can allow decimal (float) numbers
    if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1))
    {
        e.Handled = true;
    }
}