/*--------------------------------------------------------------------------------
                                            DO MATH CLASS

                                         Modified for C# 2005

--------------------------------------------------------------------------------

Updated 1/29/07 
 
  
This class takes two numbers and an operand  to know what to do on the numbers.
X and Y are short integers and Z is a string (+,-,*,/) that tell C# to add/subtract, etc.

*/

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

namespace UsingClassesPart2
{
    class DoMath
    {
    
            public double  DoCompute(double x, double y ,string z  ) 
            {
                double Result = 0;

                switch (z)
                { 
                    case "+":
                        Result = x + y;
                        break;
                    case "-":
                        Result = x - y;
                        break;
                    case "*":
                        Result = x * y;
                        break;

                    case "/":
                        Result = x / y;
                        break;
                }
                return Result;
                
            }

    }
}




 /*-----------------------------------------------------------------------
                         U S I N G   C L A S S E S  P A R T  2

                                          Ron Kessler

                                  Updated for C# 2005

 -----------------------------------------------------------------------
 This demo introduces you to some more features of classes and also 
 introduces the "foreach" loop which I use to clear all the textboxes!

Updated 1/29/07

*/




using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace UsingClassesPart2
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }
    
        //class-level variables
       double firstNumber = 0;                    //the 1st number they enter
       double secondNumber = 0;                //secondNumber number they enter
       string mathOperand = "";                  //what to do? (+ - * /)
       DoMath getAnswer = new DoMath();  //instantiate my custom class 
 

        private void optAdd_CheckedChanged(object sender, EventArgs e)
       {
             if (optAdd.Checked == true)
                mathOperand = "+";
       }

        private void optSubtract_CheckedChanged(object sender, EventArgs e)
       {
            if (optSubtract.Checked == true)
                mathOperand = "-";
       }

        private void optMultiply_CheckedChanged(object sender, EventArgs e)
        {
            if (optMultiply.Checked == true)
                mathOperand = "*"; 
        }

        private void optDivide_CheckedChanged(object sender, EventArgs e)
        {
            if (optDivide.Checked == true)
                mathOperand = "/"; 
        }

        private void btnCompute_Click(object sender, EventArgs e)
        {
            try
               { 
                firstNumber = Convert.ToDouble(txtNumber1.Text);
                secondNumber = Convert.ToDouble(txtNumber2.Text);

                //---use the function DoCompute inside the Class Module called DoMath.cs
                txtAnswer.Text =Convert.ToString(getAnswer.DoCompute(firstNumber, secondNumber, mathOperand));
                }
            catch (Exception ex)
               { 
                MessageBox.Show("Sorry, but I can't manage that operation...try again." + ex.Message,
                "System Message",MessageBoxButtons.OK,MessageBoxIcon.Error);
               
                btnClear.PerformClick();      //simulates clicking the clear button!
                txtNumber1.Focus();
                }
         }

        private void btnClear_Click(object sender, EventArgs e)
        {
                //---this sub finds all the textboxes on the form and clears them! It searches through the controls collection and when
                //    it finds a textbox, it clears it.
                //---dim a temp object variable as a control object. It can be a button, listbox, textbox, etc.
                       
                foreach (Control myControl in Controls)    //loop through the form's control collection to find all the textboxes.
                    {
                        if (myControl is TextBox)              //found textbox? then clear text
                            myControl.Text = "";
                               
                    }
        
                    txtNumber1.Focus();
         
        }

        private void btnEnd_Click(object sender, EventArgs e)
        {
            
          DialogResult button1 = MessageBox.Show("Are you sure", "Sytem Message",
            MessageBoxButtons.YesNo,MessageBoxIcon.Question);
          
          if (button1 == DialogResult.Yes)
            this.Close();
            
        }
    }
}