Textbox validate characters digits only - Desktop App

I wanted to let the user enter onlydigits in a Textbox and validate the characters when the types.
I came up with this:

private void numericUpDown_Count_KeyPress(object sender, KeyPressEventArgs e)
{
if ("1234567890".IndexOf(e.KeyChar.ToString()) > 0)
{
e.Handled = false;
}
else
{
e.Handled = true;
}
}

tell me if there's an easier way :)