C#计算器（组合框控件）

namespace WindowsFormsApplication5{    partial class Form1    {        /// <summary>        /// 必需的设计器变量。        /// </summary>        private System.ComponentModel.IContainer components = null;        /// <summary>        /// 清理所有正在使用的资源。        /// </summary>        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>        protected override void Dispose(bool disposing)        {            if (disposing && (components != null))            {                components.Dispose();            }            base.Dispose(disposing);        }        #region Windows 窗体设计器生成的代码        /// <summary>        /// 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。        /// </summary>        private void InitializeComponent()        {            this.button1 = new System.Windows.Forms.Button();            this.textBox1 = new System.Windows.Forms.TextBox();            this.textBox2 = new System.Windows.Forms.TextBox();            this.label1 = new System.Windows.Forms.Label();            this.textBox3 = new System.Windows.Forms.TextBox();            this.comboBox1 = new System.Windows.Forms.ComboBox();            this.SuspendLayout();            //             // button1            //             this.button1.Location = new System.Drawing.Point(255, 185);            this.button1.Name = "button1";            this.button1.Size = new System.Drawing.Size(75, 23);            this.button1.TabIndex = 0;            this.button1.Text = "button1";            this.button1.UseVisualStyleBackColor = true;            this.button1.Click += new System.EventHandler(this.button1_Click);            //             // textBox1            //             this.textBox1.Location = new System.Drawing.Point(51, 75);            this.textBox1.Name = "textBox1";            this.textBox1.Size = new System.Drawing.Size(100, 21);            this.textBox1.TabIndex = 2;            //             // textBox2            //             this.textBox2.Location = new System.Drawing.Point(266, 74);            this.textBox2.Name = "textBox2";            this.textBox2.Size = new System.Drawing.Size(100, 21);            this.textBox2.TabIndex = 3;            //             // label1            //             this.label1.AutoSize = true;            this.label1.Location = new System.Drawing.Point(385, 77);            this.label1.Name = "label1";            this.label1.Size = new System.Drawing.Size(41, 12);            this.label1.TabIndex = 4;            this.label1.Text = "label1";            //             // textBox3            //             this.textBox3.Location = new System.Drawing.Point(448, 75);            this.textBox3.Name = "textBox3";            this.textBox3.Size = new System.Drawing.Size(100, 21);            this.textBox3.TabIndex = 5;            //             // comboBox1            //             this.comboBox1.FormattingEnabled = true;            this.comboBox1.Location = new System.Drawing.Point(184, 75);            this.comboBox1.Name = "comboBox1";            this.comboBox1.Size = new System.Drawing.Size(46, 20);            this.comboBox1.TabIndex = 6;                       //             // Form1            //             this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;            this.ClientSize = new System.Drawing.Size(607, 262);            this.Controls.Add(this.comboBox1);            this.Controls.Add(this.textBox3);            this.Controls.Add(this.label1);            this.Controls.Add(this.textBox2);            this.Controls.Add(this.textBox1);            this.Controls.Add(this.button1);            this.Name = "Form1";            this.Text = "Form1";            this.Load += new System.EventHandler(this.Form1_Load);            this.ResumeLayout(false);            this.PerformLayout();        }        #endregion        private System.Windows.Forms.Button button1;        private System.Windows.Forms.TextBox textBox1;        private System.Windows.Forms.TextBox textBox2;        private System.Windows.Forms.Label label1;        private System.Windows.Forms.TextBox textBox3;        private System.Windows.Forms.ComboBox comboBox1;    }}

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 WindowsFormsApplication5{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void Form1_Load(object sender, EventArgs e)        {            label1.Text = "=";            button1.Text = "运算";            comboBox1.Items.Add("+");            comboBox1.Items.Add("-");            comboBox1.Items.Add("*");            comboBox1.Items.Add("/");                   }        string text;            private void button1_Click(object sender, EventArgs e)        {            switch (comboBox1.Text)            {                case "+":                    text = (double.Parse(textBox1.Text) + double.Parse(textBox2.Text)).ToString();                    break;                case "-":                    text = (double.Parse(textBox1.Text) - double.Parse(textBox2.Text)).ToString();                    break;                case "*":                    text = (double.Parse(textBox1.Text) * double.Parse(textBox2.Text)).ToString();                    break;                case "/":                    text = (double.Parse(textBox1.Text) / double.Parse(textBox2.Text)).ToString();                    break;                default:                    break;            }            textBox3.Text = text;        }    }}