C# 微型计算器（实现了加减乘除）

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 WindowsFormsApplication8
{
    public partial class Form1 : Form
    {
        public Form1（）
        {
            InitializeComponent（）;
        }

        private void Form1_Load（object sender EventArgs e）
        {

        }

        private void textBox3_TextChanged（object sender EventArgs e）
        {

        }

        private void textBox2_TextChanged（object sender EventArgs e）
        {

        }

        private void textBox1_TextChanged（object sender EventArgs e）
        {

        }

        private void button5_Click（object sender EventArgs e）
        {
            textBox1.Text = ““;
            textBox2.Text = ““;
            textBox3.Text = ““;
        }

        private void button1_Click（object sender EventArgs e）
        

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件      11776  2019-12-06 15:19  WindowsFormsApplication8\WindowsFormsApplication8\bin\Debug\WindowsFormsApplication8.exe

     文件      30208  2019-12-06 15:19  WindowsFormsApplication8\WindowsFormsApplication8\bin\Debug\WindowsFormsApplication8.pdb

     文件      22472  2019-12-06 15:20  WindowsFormsApplication8\WindowsFormsApplication8\bin\Debug\WindowsFormsApplication8.vshost.exe

     文件        490  2012-06-06 02:06  WindowsFormsApplication8\WindowsFormsApplication8\bin\Debug\WindowsFormsApplication8.vshost.exe.manifest

     文件       3135  2019-12-06 15:19  WindowsFormsApplication8\WindowsFormsApplication8\Form1.cs

     文件       8105  2019-12-06 15:17  WindowsFormsApplication8\WindowsFormsApplication8\Form1.Designer.cs

     文件       5817  2019-12-06 15:17  WindowsFormsApplication8\WindowsFormsApplication8\Form1.resx

     文件        863  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\DesignTimeResolveAssemblyReferences.cache

     文件       6963  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache

     文件       1154  2019-12-06 15:26  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.csproj.FileListAbsolute.txt

     文件        975  2019-12-06 15:17  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.csproj.GenerateResource.Cache

     文件       2209  2019-12-06 14:03  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.csprojResolveAssemblyReference.cache

     文件      11776  2019-12-06 15:19  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.exe

     文件        180  2019-12-06 15:17  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.Form1.resources

     文件      30208  2019-12-06 15:19  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.pdb

     文件        180  2019-12-06 14:03  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\WindowsFormsApplication8.Properties.Resources.resources

     文件        505  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\Program.cs

     文件       1386  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\Properties\AssemblyInfo.cs

     文件       2900  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\Properties\Resources.Designer.cs

     文件       5612  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\Properties\Resources.resx

     文件       1111  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\Properties\Settings.Designer.cs

     文件        249  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\Properties\Settings.settings

     文件       3761  2019-12-06 14:03  WindowsFormsApplication8\WindowsFormsApplication8\WindowsFormsApplication8.csproj

     文件        962  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8.sln

    ..A..H.     11776  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8.v11.suo

     目录          0  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug\TempPE

     目录          0  2019-12-06 14:03  WindowsFormsApplication8\WindowsFormsApplication8\bin\Debug

     目录          0  2019-12-06 15:19  WindowsFormsApplication8\WindowsFormsApplication8\obj\Debug

     目录          0  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\bin

     目录          0  2019-12-06 12:14  WindowsFormsApplication8\WindowsFormsApplication8\obj

............此处省略6个文件信息