Calculate cost of meal

// Purpose: To calculate an Overall Total for the cost of a multi-person 
// meal a restaurant.

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

namespace _304_PennerT_MockExam1
{
    public partial class mealCalculatorForm : Form
    {
        // Declare Constants
        private decimal SALES_TAX = .07m;
        private decimal TIP_RATE = .15m;

        // Identify fields (same as a variable except at class level with lifetime of application running)
        private decimal overallTotal = 0.0m;

        public mealCalculatorForm()
        {
            InitializeComponent();
        }
        private void knifeforkPictureBox_Click(object sender, EventArgs e)
        {
            try
            {
                // Declare Varialbles
                decimal charge;
                decimal salesTax;
                decimal tip;
                decimal total;

                // Convert Text Box Values (string values) to appropriate data 
                // type using a Parse method and assign to related variable.
                charge = decimal.Parse(chargeTextBox.Text);

                // Process Calculations
                // This is often 4th section following constants, variables, and 
                // conversion of text box values to data type.
                salesTax = charge * SALES_TAX;
                tip = charge * TIP_RATE;
                total = charge + salesTax + tip;

                // Accumulate Total Charges - field declared at class level.
                overallTotal += total;

                // Display Numeric Output to appropriate control by converting 
                // the numeric value to a string value using the ToString method.
                salesTaxTextBox.Text = salesTax.ToString("c");
                tipTextBox.Text = tip.ToString("c");
                totalTextBox.Text = overallTotal.ToString("c");
                overallTotalTextBox.Text = overallTotal.ToString("c");
            }
            catch (Exception ex)
            {
                // Display the default error message and set focus.
                MessageBox.Show(ex.Message);
                
                // Set Focus
                chargeTextBox.Focus();
            }
                    }  
        private void clearButton_Click(object sender, EventArgs e)
        {
            // Clear values from all meals.
            chargeTextBox.Clear();
            salesTaxTextBox.Clear();
            tipTextBox.Clear();
            totalTextBox.Clear();
            overallTotalTextBox.Clear();

            // Set Focus
            chargeTextBox.Focus();
        }
        private void exitButton_Click(object sender, EventArgs e)
        {
            // Exit form application
            this.Close();

            // Set Focus
            chargeTextBox.Focus();
        }
    }
}

Select allOpen in new window