C#编写简单计算器

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace jisuan
{
///
/// Form1 的摘要说明.
///
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.TextBox textBox2;
private System.Windows.Forms.TextBox textBox3;
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.Button button1;
private System.Windows.Forms.Button button2;
private System.Windows.Forms.Button button3;
///
/// 必需的设计器变量.
///
private System.ComponentModel.Container components = null;
public Form1()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();
//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//
}
///
/// 清理所有正在使用的资源.
///
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows 窗体设计器生成的代码
///
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容.
///
private void InitializeComponent()
{
this.textBox1 = new System.Windows.Forms.TextBox();
this.textBox2 = new System.Windows.Forms.TextBox();
this.textBox3 = new System.Windows.Forms.TextBox();
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.button1 = new System.Windows.Forms.Button();
this.button2 = new System.Windows.Forms.Button();
this.button3 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(24, 72);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(100, 21);
this.textBox1.TabIndex = 0;
this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
//
// textBox2
//
this.textBox2.Location = new System.Drawing.Point(312, 72);
this.textBox2.Name = "textBox2";
this.textBox2.Size = new System.Drawing.Size(100, 21);
this.textBox2.TabIndex = 1;
//
// textBox3
//
this.textBox3.Location = new System.Drawing.Point(448, 72);
this.textBox3.Name = "textBox3";
this.textBox3.Size = new System.Drawing.Size(88, 21);
this.textBox3.TabIndex = 2;
//
// comboBox1
//
this.comboBox1.Items.AddRange(new object[] {
"+",
"-",
"*",
"/"});
this.comboBox1.Location = new System.Drawing.Point(152, 72);
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size(121, 20);
this.comboBox1.TabIndex = 3;
this.comboBox1.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
//
// button1
//
this.button1.Location = new System.Drawing.Point(64, 184);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(104, 32);
this.button1.TabIndex = 4;
this.button1.Text = "计算";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// button2
//
this.button2.Location = new System.Drawing.Point(216, 192);
this.button2.Name = "button2";
this.button2.Size = new System.Drawing.Size(75, 23);
this.button2.TabIndex = 5;
this.button2.Text = "清除";
this.button2.Click += new System.EventHandler(this.button2_Click);
//
// button3
//
this.button3.Location = new System.Drawing.Point(376, 192);
this.button3.Name = "button3";
this.button3.Size = new System.Drawing.Size(75, 23);
this.button3.TabIndex = 6;
this.button3.Text = "退出";
this.button3.Click += new System.EventHandler(this.button3_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(656, 366);
this.Controls.Add(this.button3);
this.Controls.Add(this.button2);
this.Controls.Add(this.button1);
this.Controls.Add(this.comboBox1);
this.Controls.Add(this.textBox3);
this.Controls.Add(this.textBox2);
this.Controls.Add(this.textBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
this.PerformLayout();
}
#endregion
///
/// 应用程序的主入口点.
///
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
public double jia(double a,double b)
{
return a+b;
}
public double jian(double a,double b)
{
return a-b;
}
public double cheng(double a,double b)
{
return a*b;
}
public double chu(double a,double b)
{
return a/b;
}
private void comboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
}
private void textBox1_TextChanged(object sender, System.EventArgs e)
{
}
private void button1_Click(object sender, System.EventArgs e)
{
string i=this.comboBox1.SelectedItem.ToString();
switch(i)
{

case "+":this.textBox3.Text=this.jia(double.Parse(this.textBox1.Text),double.Parse(this.textBox2.Text)).ToString();

break;
case "-":this.textBox3.Text=this.jian(double.Parse(this.textBox1.Text),double.Parse(this.textBox2.Text)).ToString();
break;
case "*":this.textBox3.Text=this.cheng(double.Parse(this.textBox1.Text),double.Parse(this.textBox2.Text)).ToString();
break;
case"/" :this.textBox3.Text=this.chu(double.Parse(this.textBox1.Text),double.Parse(this.textBox2.Text)).ToString();
break;
}
}
private void button2_Click(object sender, System.EventArgs e)
{
this.textBox1.Text=null;
this.textBox2.Text=null;
this.textBox3.Text = null;
}
private void button3_Click(object sender, EventArgs e)
{

//this.Hide();
Application.Exit();
//this.Close();

}
}
}