如何用C#编制一个简单的计算器？

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace 计算器
{
public partial class Form1 : Form
{
int jz = 1;
int shijinzhi = 0;
public Form1()
{
InitializeComponent();
}

private void radioButton1_CheckedChanged(object sender, EventArgs e)
{
switch(jz)
{
case 2: result.Text = Convert.ToInt32(result.Text, 16).ToString(); break;
case 3: result.Text = Convert.ToInt32(result.Text, 8).ToString(); break;
case 4: result.Text = Convert.ToInt32(result.Text, 2).ToString(); break;

}
jz = 1;

}

private void result_TextChanged(object