how to program a windows standard calculator

Casper

Project Name: how to program a windows standard calculator
Programmer: vivounicorn
Type: Math
Technology: C#
IDE: NONE
Description: the function of windows calculator is so strong even standard version,it can process expression like this:"2+==*.3-4+5===" or "2.5*3-.6+4.4=+==-=" and so on,I think make a calculator without any bug is hard,so a good design can help you to decrease your bug
Calculator.cs:
csharp code

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace NewCalculator
{
    public enum Operator { NO_OP, ADD, SUB, MUL, DIV, EQUAL, SQRT, BACKWARDS,PERCENT }

    internal class CalculatorOperation
    {
        public delegate decimal MathematicOperating(decimal opt1, decimal opt2);

        public delegate decimal OtherOperating(decimal opt1);

        public static Hashtable hashTable;

        static CalculatorOperation()
        {
            hashTable = new Hashtable();
            hashTable.Add("+", Operator.ADD);
            hashTable.Add("-", Operator.SUB);
            hashTable.Add("*", Operator.MUL);
            hashTable.Add("/", Operator.DIV);
            hashTable.Add("=", Operator.EQUAL);
        }

        private static decimal Add(decimal op1, decimal op2)
        {
            return decimal.Add(op1, op2);
        }

        private static decimal Sub(decimal op1, decimal op2)
        {
            return decimal.Subtract(op1, op2);
        }

        private static decimal Mul(decimal op1, decimal op2)
        {
            return decimal.Multiply(op1, op2);
        }

        private static decimal Div(decimal op1, decimal op2)
        {
           // if (op2 != 0)
                return decimal.Divide(op1, op2);
            //else
             //   return decimal.MinValue;
        }

        private static decimal Sqrt(decimal op1)
        {
            return (decimal)Math.Sqrt((double)op1);
        }

        private static decimal Backwords(decimal op1)
        {
            return 1 / op1;
        }

        private static decimal Percent(decimal op1)
        {
            return op1 / 100;
        }


        public static MathematicOperating Mathematic(Operator opt)
        {
            MathematicOperating MO = null;

            if (opt == Operator.ADD)
            {
                MO = new MathematicOperating(CalculatorOperation.Add);
                return MO;
            }

            if (opt == Operator.SUB)
            {
                MO = new MathematicOperating(CalculatorOperation.Sub);
                return MO;
            }

            if (opt == Operator.MUL)
            {
                MO = new MathematicOperating(CalculatorOperation.Mul);
                return MO;
            }

            if (opt == Operator.DIV)
            {
                MO = new MathematicOperating(CalculatorOperation.Div);
                return MO;
            }

            
            return null;
        }

        public static OtherOperating OtherMathematic(Operator opt)
        {
            OtherOperating MO;

            if (opt == Operator.SQRT)
            {
                MO = new OtherOperating(CalculatorOperation.Sqrt);
                return MO;
            }
            if (opt == Operator.BACKWARDS)
            {
                MO = new OtherOperating(CalculatorOperation.Backwords);
                return MO;
            }

            if (opt == Operator.PERCENT)
            {
                MO = new OtherOperating(CalculatorOperation.Percent);
                return MO;
            }
            return null;
        }
    }
}

CalculatorController.cs
csharp code

using System;
using System.Collections.Generic;
using System.Text;

namespace NewCalculator
{
    public delegate void Change(string str);

    public class CalculatorController:IController
    {
        #region Ë½ÓÐ×Ö¶Î
       
        private decimal mStore = 0;
    
        private decimal mResult = 0;
    
        private string mDisplay = string.Empty;

    
        private decimal opt1 = 0;
   
        private decimal opt2 = 0;
   
        private bool opt1IsReady = false;
         private bool opt2IsReady = false;
 
        private Operator currentOperator = Operator.NO_OP;

   
        private bool isClickOperatingButton = false;
  
        private bool isClickDigitalButton = false;

    
        private bool isCalculating = false;
 
        private Change onChange = null;

        #endregion
                        
        #region ¹«¹²ÊôÐÔ
     
        public string Display
        {
            get
            {
                return this.mDisplay;
            }
            set
            {
                this.mDisplay = value;
            }
        }
   
        public Change OnChange
        {
            get
            {
                return this.onChange;
            }
            set
            {
                onChange = value;
            }

        }
        #endregion

        #region Ë½ÓÐ·½·¨

 
        private bool MathematicProcess(Operator curOpt)
        {
            if (currentOperator == Operator.NO_OP)
            {
                if (curOpt != Operator.EQUAL)
                    this.currentOperator = curOpt;
                this.opt1IsReady = true;
                this.opt2IsReady = false;
                this.isCalculating = false;
                return false;
            }
            else
            {
           
                if (Operator.EQUAL != curOpt)
                {
                    if (this.opt1IsReady && this.opt2IsReady && !this.isCalculating)
                    {
                        this.mResult =
						CalculatorOperation.Mathematic(this.currentOperator)(this.opt1, this.opt2);
                        this.mDisplay = this.mResult.ToString();
                        opt1 = this.mResult;
                        this.opt1IsReady = true;
                        this.opt2IsReady = false;
                        
                        this.isCalculating = false;
                    }
                    if (curOpt != this.currentOperator)
                    {
                        this.currentOperator = curOpt;
                    }
                    //  2+3-4=3==
                    {
                        this.opt1 = decimal.Parse(this.mDisplay.ToString());
                        this.opt2IsReady = false;
                        this.isCalculating = false;
                    }

                }
                
                if (Operator.EQUAL == curOpt)
                {
                    if (this.opt1IsReady && this.opt2IsReady)
                    {
                        this.mResult = CalculatorOperation.Mathematic(this.currentOperator)(this.opt1, this.opt2);
                        opt1 = this.mResult;
                        this.mDisplay = this.mResult.ToString();
                        this.opt1IsReady = true;
                        this.opt2IsReady = true;
                    }
                    if (this.opt1IsReady && !this.opt2IsReady)
                    {
                        /////////////////////////////////
                        this.mResult = decimal.Parse(this.mDisplay.ToString());

                        this.mResult = CalculatorOperation.Mathematic(this.currentOperator)(this.mResult, this.opt1);
                        this.mDisplay = this.mResult.ToString();
                        this.opt1IsReady = true;
                        this.opt2IsReady = false;
                    }
           
                    this.isCalculating = true;
                }
                return true;
            }
        }

        #endregion

        #region ¹«¹²·½·¨
 
        public void InitializeCalculatorController()
        {
            this.mDisplay = string.Empty;
            this.mResult = 0;
            this.opt1 = 0;
            this.opt2 = 0;
            this.opt1IsReady = false;
            this.opt2IsReady = false;
            currentOperator = Operator.NO_OP;
            isClickOperatingButton = true;
            isCalculating = false;
        }

      
        public void FunctionButtonClick(string sSub)
        {
            if ("MC" == sSub.Trim().ToUpper())
            {
                this.mStore = 0;

                if (OnChange != null)
                    OnChange("");
                return;
            }
            if ("MR" == sSub.Trim().ToUpper())
            {
                /////////////////////////////////////////////
                this.isCalculating = false;

                this.mDisplay = this.mStore.ToString();
                return;
            }
            if ("MS" == sSub.Trim().ToUpper())
            {
                this.mStore = decimal.Parse(this.mDisplay);

                if (OnChange != null)
                    OnChange("M");
                return;
            }
            if ("M+" == sSub.Trim().ToUpper())
            {
                this.mStore += decimal.Parse(this.mDisplay);

                if (OnChange != null)
                    OnChange("M");

                return;
            }
        }

   
        public void BackspaceClick()
        {
            if (!this.isCalculating)
            {
                if (this.mDisplay.Length > 1)
                {
                    this.mDisplay = this.mDisplay.Substring(0, this.mDisplay.Length - 1);
                }
                else
                {
                    this.mDisplay = "0";
                }
            }
        }

 
        public bool DigitalButtonClick(string sSub)
        {
            try
            {
                isClickDigitalButton = true;

                if ("+/-" != sSub.Trim() && !(sSub.Equals("0") && sSub.Equals(this.mDisplay.Trim())))
                {
                    if (!sSub.Equals("0") && this.mDisplay.Equals("0") && !sSub.Equals("."))
                    {
                        this.mDisplay = sSub;
                        return true;
                    }

                    if (sSub.Equals("."))
                    {
                        if (this.mDisplay.IndexOf(".") >= 0)//////23-3+2.2=.3===
                        {
                            if (this.isCalculating)
                            {
                                this.mDisplay = "0";
                                isClickOperatingButton = false;
                                return true;
                            }
                            return false;
                        }

                        if (this.isClickOperatingButton)
                        {
                            if (this.mDisplay.Equals("0") || this.mDisplay.Equals(""))
                            {
                                this.mDisplay = "0";
                                isClickOperatingButton = false;
                                return true;
                            }
                        }
                    }

                    if (!this.isClickOperatingButton)
                    {
                        this.mDisplay += sSub;
                    }
                    else
                    {
                        isClickOperatingButton = false;
                        this.mDisplay = sSub;
                    }
                }
                else
                    if ("+/-" == sSub.Trim())
                    {
                        decimal tmp = 0.0m - decimal.Parse(this.mDisplay);
                        if (tmp == 0)
                        {
                            if (this.mDisplay.IndexOf('-') >= 0)
                                this.mDisplay = this.mDisplay.Substring(1, this.mDisplay.Length-1);
                            else
                                this.mDisplay = "-" + tmp.ToString();
                        }
                        else
                            this.mDisplay = tmp.ToString();
                    }
                return true;
            }
            catch
            {
                return false;
            }
        }

      
        public bool OperatingButtonClick(string sSub)
        {
            try
            {
                if (!this.opt1IsReady)
                {
                    this.opt1 = decimal.Parse(this.mDisplay);
                    this.opt1IsReady = true;
                }
                else
                    if (isClickDigitalButton && !this.opt2IsReady) 
                    {
                        this.opt2IsReady = true;
                        this.opt2 = decimal.Parse(this.mDisplay);
                    }
                isClickOperatingButton = true;
                isClickDigitalButton = false;

                MathematicProcess((Operator)CalculatorOperation.hashTable[sSub]);

                return true;
            }
            catch
            {
                return false;
            }
        }

       
        public bool ExecuteExpression(string expression, Change change)
        {
            bool flag = true;

            foreach (char ch in expression)
            {
                if (ch >= '0' && ch <= '9' || '.' == ch)
                {
                    flag = this.DigitalButtonClick(ch.ToString());
                    change(this.mDisplay);
                    continue;
                }

                if ('+' == ch || '-' == ch || '*' == ch || '/' == ch || '=' == ch)
                {
                    flag = this.OperatingButtonClick(ch.ToString());
                    change(this.mDisplay);
                    continue;
                }
            }

            return flag;
        }

      
        public decimal OtherCalculationg(string opt)
        {
            if ("sqrt" == opt.ToLower())
            {
                this.isClickOperatingButton = true;
                return CalculatorOperation.OtherMathematic(Operator.SQRT)(decimal.Parse(this.mDisplay));
            }
            if ("1/x" == opt.ToLower())
            {
                this.isClickOperatingButton = true;
                return CalculatorOperation.OtherMathematic(Operator.BACKWARDS)(decimal.Parse(this.mDisplay));
            }
            if ("%" == opt.ToLower())
            {
                this.isClickOperatingButton = true;
                return CalculatorOperation.OtherMathematic(Operator.PERCENT)(decimal.Parse(this.mDisplay));
            }
            return 0.0m;
        }
        #endregion
    }
}

Attachment:

Calculator.JPG [ 19.36 KiB | Viewed 6014 times ]

DrRakha

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how to program a windows standard calculator

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