C#简单计算器

1、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 简单计算器Form(public partial class Forml :public Forml ()InitializeComponent();key = 0;firstNumber = 0;lastNumber

2、 = 0; / 初始化private double firstNumber; / 保存第个数值private double lastNumber; / 保存第二个数值int key; /操作符标记。1为+， 2为-，3为*，4为/private void buttonl0_Click( objectEventArgs e) /Isender,textBox1. Text +=1private void button9_Click( objectEventArgs e) /2sender,textBox1. Text +=private void buttonll_Click( objectEv

3、entArgs e) /3sender,textBox1. Text +=;private void button5_Click( objectsender,EventArgs e) /4textBox1.Text +=private voidbutton2_Click( object sender,EventArgs e) /5textBox1. Text 丄5；private void button8_Click(object sender,EventArgs e) /66textBox1.Text+= private voidbuttonl_Click( object sender,Ev

4、entArgs e) /77.textBox1. Text +=?private void button7_Click( object sender,EventArgs e) /8 textBox1.Text += 8private void button3_Click( object sender,EventArgs e) /9 textBox1. Text += 9 ;private void buttonl4_Click( object sender,EventArgs e) /0if (textBoxl. Text. StartsWith( 0 ) &text Box 1. Tex t

5、 Length = 1)return : /角军决000000问题textBox1.Text += 0 ；private void buttonl3_Click( object sender,Eve nt Args e) /text Box 1. Tex t Cont ains ( “ )/C#中Contains 一般是验证对象是否包含指定的子对象/ 根.据 list. Contains (/z,/z)案!J断.list 可 能是一个 string 或者 ArrayList./验证list里面是否包含了一个,字符串. return;/解决.开头，且不能出现多个.的问题textBox1. Tex

6、t +=;private void buttonl5_Click( object sender,EventArgs e) /+if (textBox1.Text 二二 ) return ;firstNumber =Convert ToDouble (textBox1.Text); / 彳各 textBox1.Text转换为doubletextBox 1. TextHH=key = 1；private void buttonl2_Click( objectEventArgs e) /-if (textBoxl. Text =” )return ;firstNumber =Convert ToDo

7、uble (textBox1. Text); textBox1. Text 二 key二 2;priva.te void button6_Click( objectEventArgs e) /*(if (textBox1. Text 二二“)returnsendersenderfirstNumberConvert ToDouble (textbox1.Text);textBox1.Text 二 key = 曲3;)private void button4_Click( objectEve nt Args e) /，/，if (textBoxl. Text =” ) return ;firstN

8、umber =Convert ToDouble (textBox1.Text);textBox1.Text 二 key = 4;private void buttonl6_Click( objectEventArgs e) / =if (textBox1. Text = “ ) return :sender,sender,lastNumber =Convert . ToDouble(textBoxl. Text) ; /convert 函数 用来 转换数据类型switch (key)case 1: textBox1. Text 二(fiistNumber + lastNumber) ToStr

9、ing();break ;case 2: textBox1.Text 二 (firstNumber-lastNumber)ToString(); break ;case 3: textBox1.Text 二 (firstNumber* lastNumber)ToString(); break ;case 4:if (lastNumber = 0) MessageBox. Show(除数不能 为0，提示)；/textBoxl. Text =除数不 能为0；return :else/ lastNumber)ToString(); breakdefauIt : return ;private void buttonl8_Click( object sender, EventArgs e) / CtextBox1. Text 二；private void buttonl7_Click( object sender, Event