简易计算器

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Reflection ;
using System.Runtime .InteropServices ;
using System.Diagnostics;


namespace 简单计算器
{
 /// <summary>
 /// Form1 的摘要说明。
 /// </summary>
 public class Form1 : System.Windows.Forms.Form
 {
  private System.Windows.Forms.Button button1;
  private System.Windows.Forms.Button button2;
  private System.Windows.Forms.Button button3;
  private System.Windows.Forms.Button button4;
  private System.Windows.Forms.Button button5;
  private System.Windows.Forms.Button button6;
  private System.Windows.Forms.Button button7;
  private System.Windows.Forms.Button button8;
  private System.Windows.Forms.Button button9;
  private System.Windows.Forms.Button button10;
  private System.Windows.Forms.TextBox textshow;
  private System.Windows.Forms.Button point;

  private System.Windows.Forms.Button div;
  private System.Windows.Forms.Button add;
  private System.Windows.Forms.Button sub;
  private System.Windows.Forms.Button mul;
  private System.Windows.Forms.Button button12;
  private System.Windows.Forms.Button button13;
  private System.Windows.Forms.Button button17;
  private System.Windows.Forms.Button clear;
  private System.Windows.Forms.Button sqr;
  private System.Windows.Forms.MainMenu mainMenu1;
  private System.Windows.Forms.Button sqrt;
  private System.Windows.Forms.MenuItem menuItem2;
  
  private System.Windows.Forms.Button button14;
  /// <summary>
  /// 必需的设计器变量。
  /// </summary>
  private System.ComponentModel.Container components = null;

[DllImport ("Shell32.dll")]
  public static extern int ShellAbout(IntPtr hWnd ,string szApp,string szOtherStuff,IntPtr hIcon);

  public Form1()
  {
   //
   // Windows 窗体设计器支持所必需的
   //
   Application.EnableVisualStyles ();
   Application.DoEvents ();
   InitializeComponent();