C\#Winform 판 계산기 구현

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    
{
  public partial class Form1 : Form
  {
    double c, d;
    string m;
    public Form1()
    {
      InitializeComponent();
    }




    private void button2_Click(object sender, EventArgs e)
    {


    }


    private void button8_Click(object sender, EventArgs e)
    {
      textBox1.Text += button8.Text;
    }


    private void button1_Click(object sender, EventArgs e)
    {
      textBox1.Text += button1.Text;
    }


    private void button2_Click_1(object sender, EventArgs e)
    {
      textBox1.Text += button2.Text;


    }


    private void button3_Click(object sender, EventArgs e)
    {
      textBox1.Text += button3.Text;
    }


    private void button4_Click(object sender, EventArgs e)
    {
      textBox1.Text += button4.Text;
    }


    private void button5_Click(object sender, EventArgs e)
    {
      textBox1.Text += button5.Text;
    }


    private void button6_Click(object sender, EventArgs e)
    {
      textBox1.Text += button6.Text;
    }


    private void button7_Click(object sender, EventArgs e)
    {
      textBox1.Text += button7.Text;


    }


    private void button9_Click(object sender, EventArgs e)
    {
      textBox1.Text += button9.Text;
    }


    private void button10_Click(object sender, EventArgs e)
    {
      textBox1.Text += button10.Text;
    }


    private void button15_Click(object sender, EventArgs e)
    {
      d= Convert.ToDouble(textBox1.Text);
      switch (m)
      { 
        case("+"):
          textBox1.Text = Convert.ToString(c+d);
          break;
        case ("-"):
          textBox1.Text = Convert.ToString(c-d);
          break;
        case ("*"):
          textBox1.Text = Convert.ToString(c * d);
          break;
        case ("/"):
          textBox1.Text = Convert.ToString(c/d);
          break;


      }
    }


    private void button11_Click(object sender, EventArgs e)
    {
      c = Convert.ToDouble(textBox1.Text);
      textBox1.Text = "";
      m = button11.Text;
    }


    private void button12_Click(object sender, EventArgs e)
    {
      c = Convert.ToDouble(textBox1.Text);
      textBox1.Text = "";
      m = button12.Text;
    }


    private void button13_Click(object sender, EventArgs e)
    {
      c= Convert.ToDouble(textBox1.Text);
      textBox1.Text = "";
      m = button13.Text;
    }


    private void button14_Click(object sender, EventArgs e)
    {
      c = Convert.ToDouble(textBox1.Text);
      textBox1.Text = "";
      m = button14.Text;
    }


    private void button16_Click(object sender, EventArgs e)
    {
      textBox1.Text = "";
    }
  }
}