老师留任务 用windows窗体做个简单的计算器，可以连续计算的，没有头绪，谁可以指导一下我呀

Question

如题

Answer 1

输入框onchange判断输入字符，如果有两个操作符的话，就把第一个操作符两边的数算出来，用结果替换，保证最多只有一个操作符，不知道这样行不行

Answer 2

网上下载一个计算器程序的源码，看看别人是怎么做的。
另外推荐一个网址：http://www.51aspx.com/

Answer 3

给你些代码，可以参考，主要是自己动手做哈.{
    public partial class caculator1 : Form
    {
        String op1,op2;           //定义两个操作数
        bool DecimalFlag;         //标识小数点是否存在
        int NumOps;               //记录操作数个数
        String LastInput;         //指示上一次按键事件的类型
        int OpFlag;               //指示将要进行的操作类型
        bool OperaterFlag;        //指示是否已经进行过操作
        String TempReadout;
        public caculator1()
        {
            InitializeComponent();//初始化界面控件
        }
        private void caculator1_Load(object sender, EventArgs e)   //对变量进行初始化赋值
        {
            DecimalFlag = false;                 //小数点标志赋为false
            OperaterFlag = false;                //尚未进行过操作
            NumOps = 0;                          //操作数个数为
            LastInput = "NONE";
            OpFlag = 0;
            ReadOut.Text = "0.";                 //文本框中初始值为“.”
        }
        public void calculate(int MyNumber)            //接收操作数
        {
            if (!OperaterFlag)                         //判断是否点击过操作符，初始值为false  如果没有点击操作符
            {
                if (DecimalFlag)                       //判断是否点击过小数点，初始值为false   如果已经点击过小数点
                {
                    ReadOut.Text = ReadOut.Text + MyNumber;   //直接把点击的数字加在框中现有数据的后面  小数点后点击的数字直接追加
                }
                else                                       //未曾点击过小数点则进行如下操作  
                {
                    if (ReadOut.Text == "0.")          
                    {
                        ReadOut.Text = MyNumber + ".";      //如果输入框中此时为“0.”，则在输入数字的后面加上小数点，如此时输入，则显示“.”
                    }
                    Else   
                    {
                        ReadOut.Text = ReadOut.Text.Substring(0, ReadOut.Text.Length - 1) + MyNumber + ".";  //框中数据后面加上小数点
                    }
                }
            }
            else
            {
                ReadOut.Text = MyNumber + ".";     //点击过操作符之后，输入的数字后面仍然加个小数点（为了显示的一致性，即任何时候框中的数据都是*.）
            }
           // DecimalFlag = false;
            OperaterFlag = false;
        }
        private void sign_Click(object sender, EventArgs e)        //正负切换（+/-）
        {
            if (ReadOut.Text != "0.")          //此时框中的数值不为“0.”
            {
                if (LastInput == "NUMS")       //上次输入的数为正数
                {
                    LastInput = "NEG";             //把LastInput置为“NEG”，表明最后一次输入的数是负数
                    ReadOut.Text = "-" + ReadOut.Text;    //给文本框中的数值前添上“-”号
                }
                else if (LastInput == "NEG")     //如果上次输入为负数
                {
                    LastInput = "NUMS";         //把LastInput置为“NUMS”，表明最后一次输入的数是正数
                    ReadOut.Text = ReadOut.Text.Substring(1, ReadOut.Text.Length - 1);  //把框中的数据最前面的符号去掉（重新变成正数）
                }
                else                     //正常情况下默认此时文本框中的数值是正数，点击+/-后，变成负数
                {
                    LastInput = "NEG";
                    ReadOut.Text = "-" + ReadOut.Text;
                } 
            }  
            else
            {
                LastInput = "NUMS";      //为“0.”时的情况
            }
        }
        private void DecimalDot_Click(object sender, EventArgs e)      //小数点（.）
        {
            if (OperaterFlag == true)
            {
                ReadOut.Text = "0.";
            }
               DecimalFlag = true;
        }
        public void StandardizationShow(String s)                     //规范化显示
        {
            if (s.IndexOf(".") == -1)
            {
                ReadOut.Text = s + "."; 
            }
            else
            {
                ReadOut.Text=s;
            }
        }
        private void Number0_Click(object sender, EventArgs e)    //点击对应的数字键时调用方法
        {
            calculate(0);
        }
        private void Number1_Click(object sender, EventArgs e)
        {
            calculate(1);
        }
        private void Number2_Click(object sender, EventArgs e)
        {
            calculate(2);
        }
        private void Number3_Click(object sender, EventArgs e)
        {
            calculate(3);
        }
        private void Number4_Click(object sender, EventArgs e)
        {
            calculate(4);
        }
        private void Number5_Click(object sender, EventArgs e)
        {
            calculate(5);
        }
        private void Number6_Click(object sender, EventArgs e)
        {
            calculate(6);
        }
        private void Number7_Click(object sender, EventArgs e)
        {
            calculate(7);
        }
        private void Number8_Click(object sender, EventArgs e)
        {
            calculate(8);
        }
        private void Number9_Click(object sender, EventArgs e)
        {
            calculate(9);
        }
        public void OperatorCal(int MyOperator)                  //接收操作符
        {
            if(!OperaterFlag)             //判断以前是否单击过操作符，避免连击操作符错误
            {
                NumOps = NumOps + 1;  
            }
  
            switch (NumOps)
            {
                case 0:
                    OperaterFlag = true;
                    break;
                case 1:
                    op1 = ReadOut.Text;
                    OperaterFlag = true;
                    break;
                case 2:
                    op2 = ReadOut.Text;
                    switch (OpFlag)
                    {
                        case 1:
                            op1 = (Double.Parse(op1) + Double.Parse(op2)).ToString();  //加
                            break;
                        case 3:
                            op1 = (Double.Parse(op1) - Double.Parse(op2)).ToString();  //减
                            break;
                        case 2:
                            op1 = (Double.Parse(op1) * Double.Parse(op2)).ToString();//乘
                            break;
                        case 0:
                            if (Double.Parse(op2) == 0)                                //除
                            {
                                MessageBox.Show("除数不能为", "计算器");
                            }
                            else
                            {
                                try
                                {
                                    op1 = (Double.Parse(op1) / Double.Parse(op2)).ToString();
                                }
                                catch (Exception e)
                                {
                                    Console.WriteLine("Generic Exception Handler: {0}", e.ToString());
                                }
                            }
                            break;
                        case 4:
                            op1 = op2;                        //等                                               
                            break;
                    }
                    TempReadout = op1;
                    this.StandardizationShow(TempReadout);
                    NumOps = 1;
                    break;
            }
            if(NumOps!=0)
            {
                OpFlag = MyOperator;
            }
            OperaterFlag = true;
            DecimalFlag = false;                              
           // LastInput = "NUMS";
        }
        private void operator1_Click(object sender, EventArgs e)
        {
            OperatorCal(1);
        }
        private void operator3_Click(object sender, EventArgs e)
        {
            OperatorCal(3);
        }
        private void operator2_Click(object sender, EventArgs e)
        {
            OperatorCal(2);
        }