設計的一個計算器類的源代碼,很簡陋哦,請各位高手不要見笑!

//名字空間MyCalClass
//類名: CalClass
//無參的構造函數CalClass()
//6個用到的私有變量
//void PointClick()  按小數點
//string CE()  是計算器復位用的,clear函數
//string BackSpace(string Txt)  倒退鍵,參數是計算過程中現在顯示的計算結果
//string NumClick(string Txt,int NumKey)  0-9數字鍵按下的響應,Txt是計算的當前結果,NumKey是按下的數字值
//string OpClick(string Txt,int OpKey) +,-,*,/,=幾個鍵按下時的處理,Txt是計算的當前結果,OpKey是按下操作鍵的數字ID
namespace MyCalClass
{
    public class CalClass
    {
        private string ResultTxt;    //Get and Show The Result of the TextBox in application
        private bool PointIsDown;    //If the radix point was clicked;
        private double MidResult;    //To Store middle results
        private double Results;    //To store finally result
        private int LastClick;    //To sign last clicking button class,is number(1) or operator(2)
        private int LastOperator;    //To sign last clicked button of operator is who?0 is Null,1 is +,2 is - ,3 is *,4 is /,5 is =;
       public CalClass()
        {
            ResultTxt = "0.";
            PointIsDown = false;
            MidResult = 0;
            Results = 0;
            LastClick = 0;