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设计的一个计算器类的源代码,很简陋哦,请各位高手不要见笑!

2019-11-17 05:25:21
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//名字空间MyCalClass
//类名: CalClass
//无参的构造函数CalClass()
//6个用到的私有变量
//void PointClick()  按小数点
//string CE()  是计算器复位用的,clear函数
//string BackSpace(string Txt)  倒退键,参数是计算过程中现在显示的计算结果
//string NumClick(string Txt,int NumKey)  0-9数字键按下的响应,Txt是计算的当前结果,NumKey是按下的数字值
//string OpClick(string Txt,int OpKey) +,-,*,/,=几个键按下时的处理,Txt是计算的当前结果,OpKey是按下操作键的数字IDnamespace 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;
            LastOperator = 0;
        }        public void PointClick()   //按下小数点后的函数处理
        {

            PointIsDown = true;
            return;
        }        public string CE()  //按下CE键,清理计算器
        {
            ResultTxt = "0.";
            MidResult = 0;
            Results = 0;
            PointIsDown = false;
            LastClick = 0;
            LastOperator = 0;
            return ResultTxt;
        }
        public string BackSpace(string Txt)     //后退键按下后的处理函数
        {
            if(LastClick == 2)return Txt;      //假如上次的按键是操作,不是数字,直接返回,不能再退回            if (Txt[Txt.Length - 1] == '.')       //计算器文本里最后一位是小数点时的情况:
            {
                if (PointIsDown == true) { PointIsDown = false; return Txt; }    //假如小数点按下了,则退去小数点
                else
                {
                    if (Txt.Length == 2 && Txt[0] != '0') return "0.";    //假如现在只有一位整数,"X."的情况,直接返回"0."
                    if (Txt.Length > 2) { ResultTxt = Txt.Remove(Txt.Length - 2, 2) + "."; return ResultTxt; }//否则,把最后一位去掉;
                }
            }
            else//假如最后一们不是小数点,很简单,直接把最后一们去掉就行了!
            {
                ResultTxt = Txt.Remove(Txt.Length - 1, 1);
                return ResultTxt;
            }
            return ResultTxt;//最后还要返回一个东西,程序里要求的,虽然根本运行不到这里!
        }        public string NumClick(string Txt, int NumKey)//按下数字键(0-9)后的处理函数
        {
            //ResultTxt=Txt;
            LastClick = 1;//先标志一下,最后一次按键是"数字键"
            if (Txt[Txt.Length - 1] == '.')//最后一位是小数点的情况:
            {
                if (PointIsDown == true)//小数点已经被按下
                {
                    ResultTxt = Txt + NumKey.ToString();//直接把按下的数字加到计算结果字符串上
                }
                else//小数点没被按下的话
                {
                    if (Txt.Length == 2 && Txt[0] == '0')//假如现在的数值是0.的话,则把现在的数值直接变成按下的数字
                    {
                        ResultTxt = Txt.Replace("0", NumKey.ToString());
                    }
                    else
                    {
                        ResultTxt = Txt.Insert(Txt.Length - 2, NumKey.ToString());否则,就在小数点前加上当前按下的数字
                    }
                }
            }
            else//最后一位不是小数点的情况:直接把数字加到最后
            {
                ResultTxt = Txt + NumKey.ToString();
            }
            return ResultTxt;
        }
        public string OpClick(string Txt, int OpKey)//运算操作键按下的处理
        {
            bool Haspoint=false;//用来标志已有的运算结果中,是否有小数点

            PointIsDown = false;//按下任意运算键,小数点都设为未按下状态
            if (LastClick == 2 && LastOperator != 5)//假如上一次按下的是操作运算键,并且不是等于号,则把上一次按下的内容覆盖,然后直接返回
            {
                LastClick = 2;
                LastOperator = OpKey;
                return Txt;
            }
            Results=double.Parse(Txt);//把现有的计算结果从string转为double型            switch (LastOperator)//根据上一次按下的操作按键来确定这次要做的运算
            {
                case 0:
                    MidResult=Results;//假如从未按过运算符键,则把当前的数值做为第一操作数
                    break;
                //以下1-4是计算加,减,乘,除运算
                case 1:
                    Results += MidResult;
                    break;
                case 2:
                    Results = MidResult - Results;
                    break;
                case 3:
                    Results *= MidResult;
                    break;
                case 4:
                    if (Results == 0.0) { throw new System.Exception("Can Div with 0!"); }//除数为零的异常
                    Results = MidResult / Results;
                    break;
                case 5:
                    MidResult=Results;//假如上一次按下等于号,同样要把当前的数值做为第一操作数
                    break;
            }
            ResultTxt=Results.ToString();
            for(int i=0;i<ResultTxt.Length;i++)//整数计算时,最后结尾会没有小数点,这里要加上计算结果里有没有小数点的标志
            {
                if(ResultTxt[i]=='.'){HasPoint=true;break;}
            }
            if (HasPoint) return ResultTxt;
            else return ResultTxt + ".";
        }
    }
}


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