用c#实现简易的计算器功能实例代码

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

namespace 计算器
{
public partial class Form3 : Form
{
public Form3()
{
InitializeComponent();
}
//定义变量
char oper;
double num1;
double num2;
double result = 0;
double memory=0.0;
private void Button9_Click(object sender, EventArgs e)//数字按钮的功能实现
{
Button a = (Button)sender;//判断按下的是哪个按钮
if (textBox1.Text == “0”)
{
textBox1.Text = a.Text;
}
else
textBox1.Text += a.Text;
}

private void Button16_Click(object sender, EventArgs e)//运算符按钮的功能实现
 {
  if (textBox1.Text != "")
  {
   num1 = double.Parse(textBox1.Text);
   oper = char.Parse(((Button)sender).Text);
   textBox1.Text = "";
  }
 }

 private void Button15_Click(object sender, EventArgs e)//C按钮的功能实现
 {
  textBox1.Text = "";
  textBox1.Focus();
  num1 = 0;
  num2 = 0;
  oper = ' ';
 }

 private void Button14_Click(object sender, EventArgs e)//结果按钮的功能实现
 {
  if (textBox1.Text != "")
  {
   num2 = double.Parse(textBox1.Text);
   switch (oper)
   {
    case '+': result = num1 + num2; break;
    case '-': result = num1 - num2; break;
    case '*': result = num1 * num2; break;
    case '÷': result = num1 / num2; break;
   }
   textBox1.Text = result.ToString();
  }
 }

 private void Button17_Click(object sender, EventArgs e)//小数点按钮的功能实现
 {
  if (textBox1.Text != "")
  {
   textBox1.Text += ".";
  }
  else
  {
   textBox1.Text = "0.";
  }
 }

 private void Button18_Click(object sender, EventArgs e)//M+按钮的功能实现
 {
  if(textBox1.Text!="")
  {
   label1.Text = "M";
   memory += double.Parse(textBox1.Text);
   textBox1.Text = " ";
  }
 }

 private void Button20_Click(object sender, EventArgs e)//MR按钮的功能实现
 {
  textBox1.Text = memory.ToString();
 }

 private void Button21_Click(object sender, EventArgs e)//MC按钮的功能实现
 {
  label1.Text = "";
  memory = 0;
 }

 private void Button19_Click(object sender, EventArgs e)//M-按钮的功能实现
 {
  if (textBox1.Text != "")
  {
   label1.Text = "M";
   memory -= double.Parse(textBox1.Text);
   textBox1.Text = " ";
  }
 }

}