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CS5ex Decisions - Programming Example |
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CS5ex is an example of a program with Decisions and Conditions. The source code listed below should be reviewed in detail.
Students should referred to this example when completing their CS5 assignment.
Students are NOT required to create and submit this project, but students may
download and expand the self-extracting CS5ex archive into
their own workspace if they like.
CS5ex Sample Form:
CS5exForm.cs Source Code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
//CS5ex by Your Name - CIS162AD
/*
This project uses if statements to validate the
quantity and price entered. If valid, they are used
to calculate the extended price, sales tax, shipping,
and total due. If the quantity is greater than 25, a
discount of 2% is given. The extended price is accumulated
to determine the total of all of the orders entered.
The number of orders entered are also counted, and
the accumulated extended price and number of orders entered
are used to calculate the average order amount.
Constants are used to store the sales tax and shipping rates.
*/
namespace CS5ex
{
public partial class CS5exForm : Form
{
public CS5exForm()
{
InitializeComponent();
}
//Declare class-level variables and constants
//Class variables are initialized to zero when declared
int cintOrderCount;
decimal cdecGrandTotal;
const decimal cdecTAX_RATE = 0.08M;
const decimal cdecDISCOUNT_RATE = .98M; //98% of the price is a 2% discount
const decimal cdecGROUND_SHIPPING_RATE = 5.00M;
const decimal cdecTHREE_DAY_SHIPPING_RATE = 7.00M;
const decimal cdecNEXT_DAY_SHIPPING_RATE = 10.00M;
private void btnCalculate_Click(object sender, EventArgs e)
{
// declare method variables
int intQuantity;
decimal decPrice;
decimal decExtendedPrice;
decimal decSalesTax;
decimal decShipping;
decimal decTotalDue;
decimal decAverageOrder;
//Input:
//Use nested try-catch blocks to get the input values
try
{
intQuantity = int.Parse(txtQuantity.Text);
try
{
decPrice = decimal.Parse (txtPrice.Text);
//Process:
//We now have a numeric quantity and price.
//Check if values are within the range
if (intQuantity >= 1 && intQuantity <= 50)
if (decPrice >= 5.00M && decPrice <= 15.00M)
{
//Values are valid - Continue processing
//Determine if discount should be applied
if (intQuantity > 25)
decExtendedPrice = intQuantity * (decPrice * cdecDISCOUNT_RATE);
else
decExtendedPrice = intQuantity * decPrice;
//Calculate sales tax if taxable
if (chkSalesTax.Checked == true)
decSalesTax = decExtendedPrice * cdecTAX_RATE;
else
decSalesTax = 0M;
//Determine shipping amount
if (radNextDay.Checked == true)
decShipping = cdecNEXT_DAY_SHIPPING_RATE;
else if (radThreeDay.Checked == true)
decShipping = cdecTHREE_DAY_SHIPPING_RATE;
else
decShipping = cdecGROUND_SHIPPING_RATE;
//Sum to get the total due
decTotalDue = decExtendedPrice + decSalesTax + decShipping;
//Accumulate summary totals
cdecGrandTotal += decTotalDue;
cintOrderCount += 1;
decAverageOrder = cdecGrandTotal / cintOrderCount;
//Output:
//We now have all of the values to display
lblExtendedPrice.Text = decExtendedPrice.ToString("C"); //Currency
lblSalesTax.Text = decSalesTax.ToString("C");
lblShipping.Text = decShipping.ToString("C");
lblTotalDue.Text = decTotalDue.ToString("C");
lblGrandTotal.Text = cdecGrandTotal.ToString("C");
lblNumberOfOrders.Text = cintOrderCount.ToString("N0"); //Number
lblAverageOrder.Text = decAverageOrder.ToString("C");
txtQuantity.Focus(); //get ready for next input
}
else
{
//Handle invalid price
MessageBox.Show("Price must be between $5.00 and $15.00. ",
"Data Entry Error", MessageBoxButtons.OK,
MessageBoxIcon.Exclamation);
txtPrice.SelectAll();
txtPrice.Focus();
}//endif
else
{
//Handle invalid quantity
MessageBox.Show("Quantity must be between 1 and 50. ",
"Data Entry Error", MessageBoxButtons.OK,
MessageBoxIcon.Exclamation);
txtQuantity.SelectAll();
txtQuantity.Focus();
}//endif
}//inner try
//Handle exceptions for price
catch (FormatException err)
{
MessageBox.Show("Price must be numeric. " + err.Message,
"Data Entry Error", MessageBoxButtons.OK,
MessageBoxIcon.Exclamation);
txtPrice.SelectAll();
txtPrice.Focus();
}
}//outer try
//Handle exceptions for quantity
catch (FormatException err)
{
MessageBox.Show("Quantity must be numeric. " + err.Message,
"Data Entry Error", MessageBoxButtons.OK,
MessageBoxIcon.Exclamation);
txtQuantity.SelectAll();
txtQuantity.Focus();
}
//Handle any other exceptions. Exceptions not caught by the
//inner Try will also end up here because that Try is inside the outer Try.
catch(Exception err)
{
MessageBox.Show("Unexpected Error: " + err.Message);
}
}//end of btnCalculate
private void btnClearForm_Click(object sender, EventArgs e)
{
//Use Clear or null string "" for TextBoxes, but
//only use null string "" for Labels
txtQuantity.Clear(); //Clear
txtPrice.Clear();
lblExtendedPrice.Text = ""; //null string
lblSalesTax.Text = "";
lblShipping.Text = "";
lblTotalDue.Text = "";
lblGrandTotal.Text = "";
lblNumberOfOrders.Text = "";
lblAverageOrder.Text = "";
radGround.Checked = true; //reset radio buttons
chkSalesTax.Checked = false; //reset check box
cdecGrandTotal = 0; //Reset Accumulators
cintOrderCount = 0;
txtQuantity.Focus();
}//end of btnClearForm
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}//end of btnExit
}//end of class
}//end of namespace
Revised: 02/16/2011 - www.mesacc.edu/~marquez/cis162ad/cs5ex_decisions.html