escribir solo numeros o caracteres en c#

Elementos del formulario;

Código del programa;

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)

        {

            if (e.KeyChar < '0' || e.KeyChar > '9')

                e.Handled = true;

            else

                e.Handled = false;

        }

        private void textBox2_KeyPress(object sender, KeyPressEventArgs e)

        {

            if (e.KeyChar >= '0' && e.KeyChar <= '9')

                e.Handled = true;

            else

                e.Handled = false;

        }

        private void Form1_Load(object sender, EventArgs e)

        {

        }

    }

}