form1.cs

微软（Microsoft）出版社C井练习文件及解答

#region Using directives

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

#endregion

namespace MathsOperators
{
    partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void calculate_Click(object sender, System.EventArgs e)
        {
            try
            {
                int leftHandSide = Int32.Parse(leftHandSideOperand.Text);
                int rightHandSide = Int32.Parse(rightHandSideOperand.Text);
                int answer = doCalculation(leftHandSide, rightHandSide);
                result.Text = answer.ToString();
            }

			catch (FormatException fEx)
			{
				result.Text = fEx.Message;
			}

			catch (OverflowException oEx)
			{
				result.Text = oEx.Message;
			}

			catch (InvalidOperationException ioEx)
			{
				result.Text = ioEx.Message;
			}

            catch (Exception ex)
            {
                result.Text = ex.Message;
            }
        }

        private int doCalculation(int leftHandSide, int rightHandSide)
        {
            int res = 0;

            if (addition.Checked)
                res = addValues(leftHandSide, rightHandSide);
            else if (subtraction.Checked)
                res = subtractValues(leftHandSide, rightHandSide);
            else if (multiplication.Checked)
                res = multiplyValues(leftHandSide, rightHandSide);
            else if (division.Checked)
                res = divideValues(leftHandSide, rightHandSide);
            else if (remainder.Checked)
                res = remainderValues(leftHandSide, rightHandSide);
            else
                throw new InvalidOperationException("no operator selected");

            return res;
        }

        private int addValues(int leftHandSide, int rightHandSide)
        {
            expression.Text = leftHandSide.ToString() + " + " + rightHandSide.ToString();
            return leftHandSide + rightHandSide;
        }

        private int subtractValues(int leftHandSide, int rightHandSide)
        {
            expression.Text = leftHandSide.ToString() + " - " + rightHandSide.ToString();
            return leftHandSide - rightHandSide;
        }

        private int multiplyValues(int leftHandSide, int rightHandSide)
        {
            expression.Text = leftHandSide.ToString() + " * " + rightHandSide.ToString();
            return checked(leftHandSide * rightHandSide);
        }

        private int divideValues(int leftHandSide, int rightHandSide)
        {
            expression.Text = leftHandSide.ToString() + " / " + rightHandSide.ToString();
            return leftHandSide / rightHandSide;
        }

        private int remainderValues(int leftHandSide, int rightHandSide)
        {
            expression.Text = leftHandSide.ToString() + " % " + rightHandSide.ToString();
            return leftHandSide % rightHandSide;
        }

        private void quit_Click(object sender, System.EventArgs e)
        {
            Application.Exit();
        }
    }
}