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 計(jì)算器{  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 = "";    }  }}