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XML Application: College Park Auto-Repair

Introduction

This is an example application that explores some classes of the .NET Framework used to write values to an XML file or to read values from an XML file. The classes are the XmlTextWriter and the XmlTextReader.

To follow the steps on this exercise, you should be familiar with XML. The actual functionalities of the XmlTextWriter and the XmlTextReader classes reviewed in our Lesson 10.

 

Practical Learning Practical Learning: Introducing XML-Based Applications
  1. Start Microsoft Visual Studio .NET and create a Windows Forms Application named CollegeParkAutoRepair2
  2. In the Solution Explorer, right-click Form1.cs and click Rename
  3. Type cpar.cs and press Enter
  4. From the Menus & Toolbars section of the Toolbox, click MenuStrip and click the form
  5. Design the menu items as follows:
     
    MenuItem DropDownItems
    Text Name Text Name Shortcut
    &File mnuFile &New Repair Order mnuFileNew Ctrl+N
        &Open Existing Order... mnuFileOpen Ctrl+O
        &Save Current Order mnuFileSave Ctrl+S
        Separator    
        &Print... mnuFilePrint Ctrl+P
        Print Pre&view... mnuFilePrintPreview  
        Separator    
        E&xit mnuFileExit  
  6. Design the form as follows:
     
    College Park Auto-Repair
    Control Name Text Other Properties
    Group   Order Identification  
    Label   Customer Name:  
    TextBox txtCustomerName    
    Label   Address  
    TextBox txtAddress    
    Label   City:  
    TextBox txtCity    
    Label   State:  
    TextBox txtState    
    Label   ZIP Code:  
    TextBox txtZIPCode   TextAlign: Right
    Label   Make / Model:  
    TextBox txtMake    
    TextBox txtModel    
    Label   Year:  
    TextBox txtCarYear   TextAlign: Right
    Label   Problem Description:  
    TextBox txtProblem    
    GroupBox   Parts Used  
    Label   Part Name  
    Label   Unit Price  
    Label   Qty  
    Label   Sub Total  
    TextBox txtPartName1    
    TextBox txtUnitPrice1 0.00 TextAlign: Right
    TextBox txtQuantity1 0 TextAlign: Right
    TextBox txtSubTotal1 0.00 TextAlign: Right
    Enabled: False
    TextBox txtPartName2    
    TextBox txtUnitPrice2 0.00 TextAlign: Right
    TextBox txtQuantity2 0 TextAlign: Right
    TextBox txtSubTotal2 0.00 TextAlign: Right
    Enabled: False
    TextBox txtPartName3    
    TextBox txtUnitPrice3 0.00 TextAlign: Right
    TextBox txtQuantity3 0 TextAlign: Right
    TextBox txtSubTotal3 0.00 TextAlign: Right
    Enabled: False
    TextBox txtPartName4    
    TextBox txtUnitPrice4 0.00 TextAlign: Right
    TextBox txtQuantity4 0 TextAlign: Right
    TextBox txtSubTotal4 0.00 TextAlign: Right
    Enabled: False
    TextBox txtPartName5    
    TextBox txtUnitPrice5 0.00 TextAlign: Right
    TextBox txtQuantity5 0 TextAlign: Right
    TextBox txtSubTotal5 0.00 TextAlign: Right
    Enabled: False
    GroupBox   Jobs Performed  
    Label   Price  
    TextBox txtJobPerformed1    
    TextBox txtJobPrice1 0.00 TextAlign: Right
    TextBox txtJobPerformed2    
    TextBox txtJobPrice2 0.00 TextAlign: Right
    TextBox txtJobPerformed3    
    TextBox txtJobPrice3 0.00 TextAlign: Right
    TextBox txtJobPerformed4    
    TextBox txtJobPrice4 0.00 TextAlign: Right
    TextBox txtJobPerformed5    
    TextBox txtJobPrice5 0.00 TextAlign: Right
    GroupBox   Order Summary  
    Label   Total Parts:  
    TextBox txtTotalParts 0.00 TextAlign: Right
    Label   Total Labor:  
    TextBox txtTotalLabor 0.00 TextAlign: Right
    Label   Tax Rate:  
    TextBox txtTaxRate 7.75 TextAlign: Right
    Label   %  
    Label   Tax Amount:  
    TextBox txtTaxAmount 0.00 TextAlign: Right
    Label   Total Order:  
    TextBox txtTotalOrder 0.00 TextAlign: Right
    Label   Recommendations  
    TextBox txtRecommendations   Multiline: True
    ScrollBars: Vertical
  7. Right-click the form and click View Code
  8. Create a method named Calculate as follows:
       
    using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Xml;

namespace CollegeParkAutoRepair2
{
    public partial class Exercise : Form
    {
        public Exercise()
        {
            InitializeComponent();
        }
        
        void Calculate()
        {
            double part1UnitPrice = 0.00, part2UnitPrice = 0.00,
                   part3UnitPrice = 0.00, part4UnitPrice = 0.00,
                   part5UnitPrice = 0.00;
            double part1SubTotal, part2SubTotal, part3SubTotal,
                   part4SubTotal, part5SubTotal, totalParts;
            int part1Quantity = 0, part2Quantity = 0, part3Quantity = 0,
                   part4Quantity = 0, part5Quantity = 0;
            double job1Price = 0.00, job2Price = 0.00, job3Price = 0.00,
                   job4Price = 0.00, job5Price = 0.00;
            double totalLabor;
            double taxRate = 0.00, taxAmount, totalOrder;

            // Don't charge a part unless it is clearly identified
            if (txtPartName1.Text == "")
            {
                txtUnitPrice1.Text = "0.00";
                txtQuantity1.Text = "0";
                txtSubTotal1.Text = "0.00";
                part1UnitPrice = 0.00;
            }
            else
            {
                try
                {
                    part1UnitPrice = double.Parse(txtUnitPrice1.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Unit Price");
                    txtUnitPrice1.Text = "0.00";
                    txtUnitPrice1.Focus();
                }

                try
                {
                    part1Quantity = int.Parse(txtQuantity1.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Quantity");
                    txtQuantity1.Text = "0";
                    txtQuantity1.Focus();
                }
            }

            if (this.txtPartName2.Text == "" )
            {
                txtUnitPrice2.Text = "0.00";
                txtQuantity2.Text = "0";
                txtSubTotal2.Text = "0.00";
                part2UnitPrice = 0.00;
            }
            else
            {
                try
                {
                    part2UnitPrice = double.Parse(txtUnitPrice2.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Unit Price");
                    this.txtUnitPrice2.Text = "0.00";
                    this.txtUnitPrice2.Focus();
                }

                try
                {
                    part2Quantity = int.Parse(txtQuantity2.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Quantity");
                    txtQuantity2.Text = "0";
                    txtQuantity2.Focus();
                }
            }

            if (txtPartName3.Text == "" )
            {
                txtUnitPrice3.Text = "0.00";
                txtQuantity3.Text = "0";
                txtSubTotal3.Text = "0.00";
                part3UnitPrice = 0.00;
            }
            else
            {
                try
                {
                    part3UnitPrice = double.Parse(txtUnitPrice3.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Unit Price");
                    txtUnitPrice3.Text = "0.00";
                    txtUnitPrice3.Focus();
                }

                try
                {
                    part3Quantity = int.Parse(txtQuantity3.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Quantity");
                    txtQuantity3.Text = "0";
                    txtQuantity3.Focus();
                }
            }

            if (txtPartName4.Text == "" )
            {
                txtUnitPrice4.Text = "0.00";
                txtQuantity4.Text = "0";
                txtSubTotal4.Text = "0.00";
                part4UnitPrice = 0.00;
            }
            else
            {
                try
                {
                    part4UnitPrice = double.Parse(txtUnitPrice4.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Unit Price");
                    txtUnitPrice4.Text = "0.00";
                    txtUnitPrice4.Focus();
                }

                try
                {
                    part4Quantity = int.Parse(txtQuantity4.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Quantity");
                    txtQuantity4.Text = "0";
                    txtQuantity4.Focus();
                }
            }

            if (txtPartName5.Text == "" )
            {
                txtUnitPrice5.Text = "0.00";
                txtQuantity5.Text = "0";
                txtSubTotal5.Text = "0.00";
                part5UnitPrice = 0.00;
            }
            else
            {
                try
                {
                    part5UnitPrice = double.Parse(txtUnitPrice5.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Unit Price");
                    txtUnitPrice5.Text = "0.00";
                    txtUnitPrice5.Focus();
                }

                try
                {
                    part5Quantity = int.Parse(txtQuantity5.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Quantity");
                    txtQuantity5.Text = "0";
                    txtQuantity5.Focus();
                }
            }

            // Don't bill the customer for a job that is not specified
            if (txtJobDescription1.Text == "")
            {
                txtJobPrice1.Text = "0.00";
                job1Price = 0.00;
            }
            else
            {
                try
                {
                    job1Price = double.Parse(txtJobPrice1.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Job Price");
                    txtJobPrice1.Text = "0.00";
                    txtJobPrice1.Focus();
                }
            }

            if (txtJobDescription2.Text == "")
            {
                txtJobPrice2.Text = "0.00";
                job2Price = 0.00;
            }
            else
            {
                try
                {
                    job2Price = double.Parse(txtJobPrice2.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Job Price");
                    txtJobPrice2.Text = "0.00";
                    txtJobPrice2.Focus();
                }
            }

            if (txtJobDescription3.Text == "")
            {
                txtJobPrice3.Text = "0.00";
                job3Price = 0.00;
            }
            else
            {
                try
                {
                    job3Price = double.Parse(txtJobPrice3.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Job Price");
                    txtJobPrice3.Text = "0.00";
                    txtJobPrice3.Focus();
                }
            }

            if (txtJobDescription4.Text == "")
            {
                txtJobPrice4.Text = "0.00";
                job4Price = 0.00;
            }
            else
            {
                try
                {
                    job4Price = double.Parse(txtJobPrice4.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Job Price");
                    txtJobPrice4.Text = "0.00";
                    txtJobPrice4.Focus();
                }
            }

            if (txtJobDescription5.Text == "")
            {
                txtJobPrice5.Text = "0.00";
                job5Price = 0.00;
            }
            else
            {
                try
                {
                    job5Price = double.Parse(txtJobPrice5.Text);
                }
                catch (FormatException)
                {
                    MessageBox.Show("Invalid Job Price");
                    txtJobPrice5.Text = "0.00";
                    txtJobPrice5.Focus();
                }
            }

            part1SubTotal = part1UnitPrice * part1Quantity;
            part2SubTotal = part2UnitPrice * part2Quantity;
            part3SubTotal = part3UnitPrice * part3Quantity;
            part4SubTotal = part4UnitPrice * part4Quantity;
            part5SubTotal = part5UnitPrice * part5Quantity;

            txtSubTotal1.Text = part1SubTotal.ToString("F");
            txtSubTotal2.Text = part2SubTotal.ToString("F");
            txtSubTotal3.Text = part3SubTotal.ToString("F");
            txtSubTotal4.Text = part4SubTotal.ToString("F");
            txtSubTotal5.Text = part5SubTotal.ToString("F");

            totalParts = part1SubTotal + part2SubTotal + part3SubTotal +
                    part4SubTotal + part5SubTotal;

            totalLabor = job1Price + job2Price + job3Price +
                            job4Price + job5Price;

            try
            {
                taxRate = double.Parse(txtTaxRate.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid Tax Rate");
                txtTaxRate.Text = "7.75";
                txtTaxRate.Focus();
            }

            double totalPartsAndLabor = totalParts + totalLabor;
            taxAmount = totalPartsAndLabor * taxRate / 100;
            totalOrder = totalPartsAndLabor + taxAmount;

            txtTotalParts.Text = totalParts.ToString("F");
            txtTotalLabor.Text = totalLabor.ToString("F");
            txtTaxAmount.Text = taxAmount.ToString("F");
            txtTotalOrder.Text = totalOrder.ToString("F");
        }
    }
}
  9. Return to the form
  10. On the form, click File and double-click New Repair Order
  11. Implement its Click event as follows:
      
    private void mnuFileNew_Click(object sender, EventArgs e)
{
    this.txtCustomerName.Text = "";
    this.txtAddress.Text = "";
    this.txtCity.Text = "";
    this.txtState.Text = "";
    this.txtZIPCode.Text = "";
    this.txtMake.Text = "";
    this.txtModel.Text = "";
    this.txtCarYear.Text = "";
    this.txtProblem.Text = "";

    this.txtPartName1.Text = "";
    this.txtUnitPrice1.Text = "0.00";
    this.txtQuantity1.Text = "0";
    this.txtSubTotal1.Text = "0.00";
    this.txtPartName2.Text = "";
    this.txtUnitPrice2.Text = "0.00";
    this.txtQuantity2.Text = "0";
    this.txtSubTotal2.Text = "0.00";
    this.txtPartName3.Text = "";
    this.txtUnitPrice3.Text = "0.00";
    this.txtQuantity3.Text = "0";
    this.txtSubTotal3.Text = "0.00";
    this.txtPartName4.Text = "";
    this.txtUnitPrice4.Text = "0.00";
    this.txtQuantity4.Text = "0";
    this.txtSubTotal4.Text = "0.00";
    this.txtPartName5.Text = "";
    this.txtUnitPrice5.Text = "0.00";
    this.txtQuantity5.Text = "0";
    this.txtSubTotal5.Text = "0.00";

    this.txtJobDescription1.Text = "";
    this.txtJobPrice1.Text = "0.00";
    this.txtJobDescription2.Text = "";
    this.txtJobPrice2.Text = "0.00";
    this.txtJobDescription3.Text = "";
    this.txtJobPrice3.Text = "0.00";
    this.txtJobDescription4.Text = "";
    this.txtJobPrice4.Text = "0.00";
    this.txtJobDescription5.Text = "";
    this.txtJobPrice5.Text = "0.00";

    this.txtTotalParts.Text = "0.00";
    this.txtTotalLabor.Text = "0.00";
    this.txtTaxRate.Text = "7.75";
    this.txtTaxAmount.Text = "0.00";
    this.txtTotalOrder.Text = "0.00";

    this.txtRecommendations.Text = "";
    this.txtCustomerName.Focus();
}
  12. Return to the form and click the first text box under Unit Price
  13. In the Properties window, click the Events button and double-click Leave
  14. Call the Calculate() method as follows:
      
    private void txtUnitPrice1_Leave(object sender, EventArgs e)
{
    Calculate();
}
  15. Return to the form
  16. Click each text box under Unit Price and, in the Events section of the Properties Windows, click Leave to select txtUnitPrice1_Leave
  17. Click each text box under Qty and, in the Events section of the Properties Windows, click Leave to select txtUnitPrice1_Leave
  18. Click each text box under Price (in the Jobs Performed section of the form) and, in the Events section of the Properties Windows, click Leave to select txtUnitPrice1_Leave
  19. Click the Tax Rate text box and, in the Events section of the Properties Windows, click Leave to select txtUnitPrice1_Leave
  20. From the Printing section of the Toolbox, click the PrintDocument button PrintDocument and click the form
  21. While the print document control is still selected, in the Properties window, change its name to docPrint
  22. On the bar under the form, double-click docPrint to generate its default event
  23. Implement the PrintPage event as follows:
      
    private void docPrint_PrintPage(object sender,
            System.Drawing.Printing.PrintPageEventArgs e)
{
    e.Graphics.DrawLine(new Pen(Color.Black, 2), 60, 90, 680, 90);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 60, 93, 680, 93);

    string strDisplay = "College Park Auto Repair";
    System.Drawing.Font fntString = new Font("Times New Roman", 28,
                FontStyle.Bold);
    e.Graphics.DrawString(strDisplay, fntString,
                Brushes.Black, 160, 100);

    strDisplay = "Customer Car Repair Order";
    fntString = new System.Drawing.Font("Times New Roman", 18,
                FontStyle.Bold);
    e.Graphics.DrawString(strDisplay, fntString,
                Brushes.Black, 220, 150);

    e.Graphics.DrawLine(new Pen(Color.Black, 1), 60, 184, 680, 184);
    e.Graphics.DrawLine(new Pen(Color.Black, 2), 60, 187, 680, 187);

    fntString = new System.Drawing.Font("Times New Roman", 12,
                FontStyle.Bold);
    e.Graphics.DrawString("Order Identification", fntString,
                Brushes.Black, 80, 200);

    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 250, 640, 250);

    fntString = new System.Drawing.Font("Times New Roman", 10,
                FontStyle.Bold);
    e.Graphics.DrawString("Customer Name:", fntString,
                Brushes.Black, 100, 260);
    fntString = new System.Drawing.Font("Times New Roman", 10,
               FontStyle.Regular);
    e.Graphics.DrawString(txtCustomerName.Text, fntString,
                Brushes.Black, 260, 260); ;

    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 280, 640, 280);

            fntString = new Font("Times New Roman", 10, FontStyle.Bold);
            e.Graphics.DrawString("Address:", fntString,
                Brushes.Black, 100, 290);
            fntString = new Font("Times New Roman", 10, FontStyle.Regular);
            e.Graphics.DrawString(txtAddress.Text, fntString,
                Brushes.Black, 260, 290); ;

            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 310, 640, 310);

            fntString = new Font("Times New Roman", 10, FontStyle.Regular);
            string strAddress = txtCity.Text.ToString() + ", " +
                                txtState.Text + " " + txtZIPCode.Text;
    e.Graphics.DrawString(strAddress, fntString, Brushes.Black, 260, 320);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 340, 640, 340);

            fntString = new Font("Times New Roman", 10, FontStyle.Bold);
            e.Graphics.DrawString("Car:", fntString, Brushes.Black, 100, 350);
            fntString = new Font("Times New Roman", 10, FontStyle.Regular);
            string strCar = txtMake.Text + ", " + txtModel.Text +
                            ", " + txtCarYear.Text;
            e.Graphics.DrawString(strCar, fntString, Brushes.Black, 260, 350);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 370, 640, 370);

            fntString = new Font("Times New Roman", 10, FontStyle.Bold);
            e.Graphics.DrawString("Problem Description:", fntString,
                Brushes.Black, 100, 380);
            fntString = new Font("Times New Roman", 10, FontStyle.Regular);
            e.Graphics.DrawString(txtProblem.Text, fntString,
                                  Brushes.Black,
                                  new RectangleF(260, 380, 420, 380));
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 400, 640, 400);

    fntString = new System.Drawing.Font("Times New Roman", 12,
		 FontStyle.Bold);
            e.Graphics.DrawString("Parts Used", fntString,
                Brushes.Black, 80, 430);

            e.Graphics.DrawLine(new Pen(Color.Black, 2), 80, 450, 680, 450);

            e.Graphics.DrawString("Parts Name", fntString,
                Brushes.Black, 100, 460);
            e.Graphics.DrawString("Unit Price", fntString,
                Brushes.Black, 420, 460);
            e.Graphics.DrawString("Qty", fntString,
                Brushes.Black, 520, 460);
            e.Graphics.DrawString("Sub-Total", fntString,
                Brushes.Black, 562, 460);

            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 480, 640, 480);

            fntString = new Font("Times New Roman", 10, FontStyle.Regular);
            StringFormat fmtString = new StringFormat();
            fmtString.Alignment = StringAlignment.Far;

            e.Graphics.DrawString(txtPartName1.Text, fntString,
                Brushes.Black, 100, 490);
            e.Graphics.DrawString(txtUnitPrice1.Text, fntString,
                Brushes.Black, 480, 490, fmtString);
            e.Graphics.DrawString(txtQuantity1.Text, fntString,
                Brushes.Black, 540, 490, fmtString);
            e.Graphics.DrawString(txtSubTotal1.Text, fntString,
                Brushes.Black, 630, 490, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1),
                100, 510, 640, 510);

            e.Graphics.DrawString(txtPartName2.Text, fntString,
                Brushes.Black, 100, 520);
            e.Graphics.DrawString(txtUnitPrice2.Text, fntString,
                Brushes.Black, 480, 520, fmtString);
            e.Graphics.DrawString(txtQuantity2.Text, fntString,
                Brushes.Black, 540, 520, fmtString);
            e.Graphics.DrawString(txtSubTotal2.Text, fntString,
                Brushes.Black, 630, 520, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 540, 640, 540);

            e.Graphics.DrawString(txtPartName3.Text, fntString,
                Brushes.Black, 100, 550);
            e.Graphics.DrawString(txtUnitPrice3.Text, fntString,
                Brushes.Black, 480, 550, fmtString);
            e.Graphics.DrawString(txtQuantity3.Text, fntString,
                Brushes.Black, 540, 550, fmtString);
            e.Graphics.DrawString(txtSubTotal3.Text, fntString,
                Brushes.Black, 630, 550, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1),
                100, 570, 640, 570);

            e.Graphics.DrawString(txtPartName4.Text, fntString,
                Brushes.Black, 100, 580);
            e.Graphics.DrawString(txtUnitPrice4.Text, fntString,
                Brushes.Black, 480, 580, fmtString);
            e.Graphics.DrawString(txtQuantity4.Text, fntString,
                Brushes.Black, 540, 580, fmtString);
            e.Graphics.DrawString(txtSubTotal4.Text, fntString,
                Brushes.Black, 630, 580, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 600, 640, 600);

            e.Graphics.DrawString(txtPartName5.Text, fntString,
                Brushes.Black, 100, 610);
            e.Graphics.DrawString(txtUnitPrice5.Text, fntString,
                Brushes.Black, 480, 610, fmtString);
            e.Graphics.DrawString(txtQuantity5.Text, fntString,
                Brushes.Black, 540, 610, fmtString);
            e.Graphics.DrawString(txtSubTotal5.Text, fntString,
                Brushes.Black, 630, 610, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 630, 640, 630);

            fntString = new Font("Times New Roman", 12, FontStyle.Bold);
            e.Graphics.DrawString("Jobs Performed", fntString,
                Brushes.Black, 80, 650);
            e.Graphics.DrawLine(new Pen(Color.Black, 2), 80, 670, 680, 670);

    e.Graphics.DrawString("Job Name", fntString, Brushes.Black, 100, 680);
            e.Graphics.DrawString("Price", fntString, Brushes.Black, 562, 680);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 700, 640, 700);

            fntString = new Font("Times New Roman", 10, FontStyle.Regular);

            e.Graphics.DrawString(txtJobDescription1.Text, fntString,
                Brushes.Black, 100, 710);
            e.Graphics.DrawString(txtJobPrice1.Text, fntString,
                Brushes.Black, 600, 710, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 730, 640, 730);

            e.Graphics.DrawString(txtJobDescription2.Text, fntString,
                Brushes.Black, 100, 740);
            e.Graphics.DrawString(txtJobPrice2.Text, fntString,
                Brushes.Black, 600, 740, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 760, 640, 760);

            e.Graphics.DrawString(txtJobDescription3.Text, fntString,
                Brushes.Black, 100, 770);
            e.Graphics.DrawString(txtJobPrice3.Text, fntString,
                Brushes.Black, 600, 770, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 790, 640, 790);

            e.Graphics.DrawString(txtJobDescription4.Text, fntString,
                Brushes.Black, 100, 800);
            e.Graphics.DrawString(txtJobPrice4.Text, fntString,
                Brushes.Black, 600, 800, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 820, 640, 820);

            e.Graphics.DrawString(txtJobDescription5.Text, fntString,
                Brushes.Black, 100, 830);
            e.Graphics.DrawString(txtJobPrice5.Text, fntString,
                Brushes.Black, 600, 830, fmtString);
            e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 850, 640, 850);

    fntString = new System.Drawing.Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Order Summary", fntString,
                Brushes.Black, 80, 870);
    e.Graphics.DrawLine(new Pen(Color.Black, 2), 80, 890, 680, 890);

    fntString = new System.Drawing.Font("Times New Roman", 10, FontStyle.Bold);
    e.Graphics.DrawString("Total Parts:", fntString,
                Brushes.Black, 500, 900);
    fntString = new System.Drawing.Font("Times New Roman", 10,
			 FontStyle.Regular);
    e.Graphics.DrawString(txtTotalParts.Text, fntString,
                Brushes.Black, 640, 900, fmtString);

    fntString = new System.Drawing.Font("Times New Roman", 10, FontStyle.Bold);
    e.Graphics.DrawString("Total Labor:", fntString,
                Brushes.Black, 500, 920);
    fntString = new System.Drawing.Font("Times New Roman", 10,
			 FontStyle.Regular);
    e.Graphics.DrawString(txtTotalLabor.Text, fntString,
                Brushes.Black, 640, 920, fmtString);

    fntString = new System.Drawing.Font("Times New Roman", 10, FontStyle.Bold);
    e.Graphics.DrawString("Tax Rate:", fntString,
                Brushes.Black, 500, 940);
    fntString = new System.Drawing.Font("Times New Roman", 10,
		 FontStyle.Regular);
            e.Graphics.DrawString(txtTaxRate.Text, fntString,
                Brushes.Black, 640, 940, fmtString);

    fntString = new System.Drawing.Font("Times New Roman", 10, FontStyle.Bold);
    e.Graphics.DrawString("Tax Amount:", fntString,
                Brushes.Black, 500, 960);
    fntString = new System.Drawing.Font("Times New Roman", 10,
			 FontStyle.Regular);
    e.Graphics.DrawString(txtTaxAmount.Text, fntString,
                Brushes.Black, 640, 960, fmtString);

    fntString = new System.Drawing.Font("Times New Roman", 10, FontStyle.Bold);
    e.Graphics.DrawString("Repair Total:", fntString,
                Brushes.Black, 500, 980);
    fntString = new System.Drawing.Font("Times New Roman", 10,
			 FontStyle.Regular);
    e.Graphics.DrawString(txtTotalOrder.Text, fntString,
                Brushes.Black, 640, 980, fmtString);

    fntString = new System.Drawing.Font("Times New Roman", 10, FontStyle.Bold);
    e.Graphics.DrawString("Recommendations:", fntString,
                Brushes.Black, 100, 900);
    fntString = new System.Drawing.Font("Times New Roman", 10,
			 FontStyle.Regular);
    e.Graphics.DrawString(txtRecommendations.Text, fntString,
                Brushes.Black, new RectangleF(100, 920, 350, 280));
}
  24. Return to the form
  25. From the Printing section of the Toolbox, click the PrintDialog button PrintDialog and click the form
  26. While the print control is still selected, in the Properties window, change its Name to dlgPrint 
  27. Click Document and select docPrint
  28. On the form, click File and double-click Print
  29. Implement its Click event as follows:
      
    private void mnuFilePrint_Click(object sender, EventArgs e)
{
    if ( dlgPrint.ShowDialog() == DialogResult.OK)
    {
        docPrint.Print();
    }
}
  30. Return to the form
  31. From the Printing section of the Toolbox, click PrintPreviewDialog and click the form
  32. In the Properties window, change its (Name) to dlgPrintPreview
  33. Still in the Properties windows, set its Document property to docPrint
  34. On the form, click File and double-click the Print Preview
  35. Implement the event as follows:
      
    private void mnuFilePrintPreview_Click(object sender, EventArgs e)
{
    dlgPrintPreview.ShowDialog();
}
  36. Save the file

The XML Text Writer Fundamentals

Besides the XmlDocument and the derived classes of XmlNode, the .NET Framework provides the XmlTextWriter class, which is derived from XmlWriter. The XmlTextWriter class works in a top-down approach to create, or deal with, the contents of an XML file. This class writes an XML node and moves down without referring back:

This means that, once you have created a node using the XmlTextWriter, you have no way of referring back to it.

To use an XmlTextWriter object, first declare a variable of the type of this class and initialize it using one of its three constructors.

Practical Learning Practical Learning: Creating the Elements of an XML File
  1. From the Dialogs section of the Toolbox, click SaveFileDialog and click the form
  2. Change its properties as follows:
    Title: Save Current Repair Order
    DefaultExt: xml
     Filter: Repair Orders (*.xml)|*.xml|All Files|
    Name: dlgSave
  3. On the form, click File and double-click Save Current Order
  4. To create the XML file with the desired elements, implement the event as follows:
      
    private void mnuFileSave_Click(object sender, EventArgs e)
{
    // Just in case, calculate the order now
    Calculate();
    // This number will be used to incrementally
    // create the files by their names
    int iFilename;
            string strFilename;
            // If this directory doesn't exist, create it
            // Also, get a reference to this directory for later use
            string strDirectory = @"C:\College Park Auto Repair";
            DirectoryInfo dirInfo =
                Directory.CreateDirectory(strDirectory);

            // Get the list of files, if any, from the above folder
            FileInfo[] fleList = dirInfo.GetFiles("*.xml");

            // If there is no XML file in the directory,
            // then get ready to create the first file
            if (fleList.Length == 0)
            {
                // Create the name of the (initial) file
                iFilename = 1000;
            }
            else // If there was at least one file in the directory
            {
                // Get a reference to the last file
                FileInfo fleLast = fleList[fleList.Length - 1];
                // Get the name of the last file without its extension
                string fwe = Path.GetFileNameWithoutExtension(fleLast.FullName);
                // Get the name of the file
                iFilename = int.Parse(fwe);
            }

            strFilename = strDirectory + "\\" + 
			(iFilename + 1).ToString() + ".xml";
                
            // Get ready to display it in the Save dialog box
            dlgSave.FileName = strFilename;

            // Find out if the user clicked OK 
	    // after displaying the Save dialog box
            if (dlgSave.ShowDialog() == DialogResult.OK)
            {
                XmlTextWriter wtrRepairOrder = new XmlTextWriter(strFilename,
                    Encoding.UTF8);
                wtrRepairOrder.Formatting = Formatting.Indented;
                wtrRepairOrder.Indentation = 4;

                // Create the contents of the XML file
                // Notice that we are not making an attempt to check the values
                wtrRepairOrder.WriteStartDocument();

                wtrRepairOrder.WriteStartElement("RepairOrders");
                wtrRepairOrder.WriteStartElement("Invoice");

                wtrRepairOrder.WriteElementString("CustomerName", 
			this.txtCustomerName.Text);
                wtrRepairOrder.WriteElementString("Addres", 
			this.txtAddress.Text);
                wtrRepairOrder.WriteElementString("City", 
			this.txtCity.Text);
                wtrRepairOrder.WriteElementString("State", 
			this.txtState.Text);
                wtrRepairOrder.WriteElementString("ZIPCode", 
			this.txtZIPCode.Text);
                wtrRepairOrder.WriteElementString("Make", 
			this.txtMake.Text);
                wtrRepairOrder.WriteElementString("Model", 
			this.txtModel.Text);
                wtrRepairOrder.WriteElementString("CarYear", 
			this.txtCarYear.Text);
                wtrRepairOrder.WriteElementString("ProbDescription", 
			this.txtProblem.Text);
                wtrRepairOrder.WriteElementString("PartName1", 
			this.txtPartName1.Text);
                wtrRepairOrder.WriteElementString("UnitPrice1", 
			this.txtUnitPrice1.Text);
                wtrRepairOrder.WriteElementString("Quantity1", 
			this.txtQuantity1.Text);
                wtrRepairOrder.WriteElementString("SubTotal1", 
			this.txtSubTotal1.Text);
                wtrRepairOrder.WriteElementString("PartName2", 
			this.txtPartName2.Text);
                wtrRepairOrder.WriteElementString("UnitPrice2", 
			this.txtUnitPrice2.Text);
                wtrRepairOrder.WriteElementString("Quantity2", 
			this.txtQuantity2.Text);
                wtrRepairOrder.WriteElementString("SubTotal2", 
			this.txtSubTotal2.Text);
                wtrRepairOrder.WriteElementString("PartName3", 
			this.txtPartName3.Text);
                wtrRepairOrder.WriteElementString("UnitPrice3", 
			this.txtUnitPrice3.Text);
                wtrRepairOrder.WriteElementString("Quantity3", 
			this.txtQuantity3.Text);
                wtrRepairOrder.WriteElementString("SubTotal3", 
			this.txtSubTotal3.Text);
                wtrRepairOrder.WriteElementString("PartName4", 
			this.txtPartName4.Text);
                wtrRepairOrder.WriteElementString("UnitPrice4", 
			this.txtUnitPrice4.Text);
                wtrRepairOrder.WriteElementString("Quantity4", 
			this.txtQuantity4.Text);
                wtrRepairOrder.WriteElementString("SubTotal4", 
			this.txtSubTotal4.Text);
                wtrRepairOrder.WriteElementString("PartName5", 
			this.txtPartName5.Text);
                wtrRepairOrder.WriteElementString("UnitPrice5", 
			this.txtUnitPrice5.Text);
                wtrRepairOrder.WriteElementString("Quantity5", 
			this.txtQuantity5.Text);
                wtrRepairOrder.WriteElementString("SubTotal5", 
			this.txtSubTotal5.Text);
                wtrRepairOrder.WriteElementString("JobDescription1",
			this.txtJobDescription1.Text);
                wtrRepairOrder.WriteElementString("JobPrice1", 
			this.txtJobPrice1.Text);
                wtrRepairOrder.WriteElementString("JobDescription2",
			this.txtJobDescription2.Text);
                wtrRepairOrder.WriteElementString("JobPrice2", 
			this.txtJobPrice2.Text);
                wtrRepairOrder.WriteElementString("JobDescription3", 
			this.txtJobDescription3.Text);
                wtrRepairOrder.WriteElementString("JobPrice3", 
			this.txtJobPrice3.Text);
                wtrRepairOrder.WriteElementString("JobDescription4", 
			this.txtJobDescription4.Text);
                wtrRepairOrder.WriteElementString("JobPrice4", 
			this.txtJobPrice4.Text);
                wtrRepairOrder.WriteElementString("JobDescription5", 
			this.txtJobDescription5.Text);
                wtrRepairOrder.WriteElementString("JobPrice5", 
			this.txtJobPrice5.Text);
                wtrRepairOrder.WriteElementString("TotalPart", 
			this.txtTotalParts.Text);
                wtrRepairOrder.WriteElementString("TotalLabor", 
			this.txtTotalLabor.Text);
                wtrRepairOrder.WriteElementString("TaxRate", 
			this.txtTaxRate.Text);
                wtrRepairOrder.WriteElementString("TaxAmount", 
			this.txtTaxAmount.Text);
                wtrRepairOrder.WriteElementString("TotalOrder", 
			this.txtTotalOrder.Text);
                wtrRepairOrder.WriteElementString("Recommendation", 
			this.txtRecommendations.Text);

                wtrRepairOrder.WriteEndElement();
                wtrRepairOrder.WriteEndElement();

                wtrRepairOrder.WriteEndDocument();

                wtrRepairOrder.Flush();
                wtrRepairOrder.Close();
            }
        }
  5. Execute the application to test it
  6. Create a new record and click Calculate Order:
     
  7. Click File -> Save and OK to Save the file
  8. Click File -> New Repair Order
  9. Create another repair order:
     
  10. Save it
  11. Close the form and return to your programming environment

Reading from an XML File

Once an XML file exists, you can read it to retrieve the values of its nodes. To support opening an XML file and reading its contents, the .NET Framework provides the XmlTextReader class that is derived from the XmlReader class. The XmlTextReader class is equipped with all the necessary properties and methods to explore the contents of an XML file.

Like XmlTextWriter, the XmlTextReader class reads a file from top to bottom without going back up once it has passed a node:

This means that, when using the XmlTextReader class to read an XML file, once you have read a node and moved down the file, you cannot refer back to the previous node and you cannot access a previous node: once you have passed a node, you cannot access it anymore.

Practical Learning Practical Learning: Reading the Elements of an XML File
  1. Display the form.
    From the Dialogs section of the Toolbox, click OpenFileDialog and click the form
  2. Change its properties as follows:
    Title: Open Existing Repair Order
    DefaultExt: xml
     Filter: Repair Orders (*.xml)|*.xml|All Files|
    Name: dlgOpen
  3. On the form, click File and double-click Open Existing Order
  4. Implement the Click event as follows:
      
    private void mnuFileOpen_Click(object sender, EventArgs e)
{
    XmlTextReader rdrRepairOrder = null;

    try
    {
        if (dlgOpen.ShowDialog() == DialogResult.OK)
        {
            rdrRepairOrder = new XmlTextReader(dlgOpen.FileName);

            // Scan the XML file
            while (rdrRepairOrder.Read())
            {
                // every time you find an element, find out what type it is
                // If you find text, put it in the combo box' list
                if( (XmlNodeType.Element != 0) &&
		    (rdrRepairOrder.Name == "CustomerName") )
                {
                    txtCustomerName.Text = 
			rdrRepairOrder.ReadElementString("CustomerName");
                    txtAddress.Text = 
			rdrRepairOrder.ReadElementString("Addres");
                    txtCity.Text = rdrRepairOrder.ReadElementString("City");
                    txtState.Text = rdrRepairOrder.ReadElementString("State");
                    txtZIPCode.Text = 
			rdrRepairOrder.ReadElementString("ZIPCode");
                    txtMake.Text = rdrRepairOrder.ReadElementString("Make");
                    txtModel.Text = rdrRepairOrder.ReadElementString("Model");
                    txtCarYear.Text = 
			rdrRepairOrder.ReadElementString("CarYear");
                    txtProblem.Text = 
			rdrRepairOrder.ReadElementString("ProbDescription");
                    txtPartName1.Text = 
			rdrRepairOrder.ReadElementString("PartName1");
                    txtUnitPrice1.Text = 
			rdrRepairOrder.ReadElementString("UnitPrice1");
                    txtQuantity1.Text = 
			rdrRepairOrder.ReadElementString("Quantity1");
                    txtSubTotal1.Text = 
			rdrRepairOrder.ReadElementString("SubTotal1");
                    txtPartName2.Text = 
			rdrRepairOrder.ReadElementString("PartName2");
                    txtUnitPrice2.Text = 
			rdrRepairOrder.ReadElementString("UnitPrice2");
                    txtQuantity2.Text = 
			rdrRepairOrder.ReadElementString("Quantity2");
                    txtSubTotal2.Text = 
			rdrRepairOrder.ReadElementString("SubTotal2");
                    txtPartName3.Text = 
			rdrRepairOrder.ReadElementString("PartName3");
                    txtUnitPrice3.Text = 
			rdrRepairOrder.ReadElementString("UnitPrice3");
                    txtQuantity3.Text = 
			rdrRepairOrder.ReadElementString("Quantity3");
                    txtSubTotal3.Text = 
			rdrRepairOrder.ReadElementString("SubTotal3");
                    txtPartName4.Text = 
			rdrRepairOrder.ReadElementString("PartName4");
                    txtUnitPrice4.Text = 
			rdrRepairOrder.ReadElementString("UnitPrice4");
                    txtQuantity4.Text = 
			rdrRepairOrder.ReadElementString("Quantity4");
                    txtSubTotal4.Text = 
			rdrRepairOrder.ReadElementString("SubTotal4");
                    txtPartName5.Text = 
			rdrRepairOrder.ReadElementString("PartName5");
                    txtUnitPrice5.Text = 
			rdrRepairOrder.ReadElementString("UnitPrice5");
                    txtQuantity5.Text = 
			rdrRepairOrder.ReadElementString("Quantity5");
                    txtSubTotal5.Text = 
			rdrRepairOrder.ReadElementString("SubTotal5");
                    txtJobDescription1.Text =
			rdrRepairOrder.ReadElementString("JobDescription1");
                    txtJobPrice1.Text = 
			rdrRepairOrder.ReadElementString("JobPrice1");
                    txtJobDescription2.Text =
			rdrRepairOrder.ReadElementString("JobDescription2");
                    txtJobPrice2.Text = 
			rdrRepairOrder.ReadElementString("JobPrice2");
                    txtJobDescription3.Text =
			rdrRepairOrder.ReadElementString("JobDescription3");
                    txtJobPrice3.Text = 
			rdrRepairOrder.ReadElementString("JobPrice3");
                    txtJobDescription4.Text =
			rdrRepairOrder.ReadElementString("JobDescription4");
                    txtJobPrice4.Text = 
			rdrRepairOrder.ReadElementString("JobPrice4");
                    txtJobDescription5.Text =
			rdrRepairOrder.ReadElementString("JobDescription5");
                    txtJobPrice5.Text = 
			rdrRepairOrder.ReadElementString("JobPrice5");
                    txtTotalParts.Text = 
			rdrRepairOrder.ReadElementString("TotalPart");
                    txtTotalLabor.Text = 
			rdrRepairOrder.ReadElementString("TotalLabor");
                    txtTaxRate.Text = 
			rdrRepairOrder.ReadElementString("TaxRate");
                    txtTaxAmount.Text = 
			rdrRepairOrder.ReadElementString("TaxAmount");
                    txtTotalOrder.Text = 
			rdrRepairOrder.ReadElementString("TotalOrder");
                    txtRecommendations.Text =
			rdrRepairOrder.ReadElementString("Recommendation");
                }
            }
        }
    }
    catch (XmlException)
    {
        MessageBox.Show("The file name you provided is not valid");
    }
    finally
    {
        rdrRepairOrder.Close();
    }
}
  5. Execute the application and open one the previous orders

Indentation

To include a white space when writing to the file, you can call the XmlTextWriter.WriteWhiteSpace() method. Its syntax is:

public override void WriteWhitespace(string ws);

Besides white spaces, indentation consists of setting empty spaces on the left of child nodes to make the file easier to read. Based on this, indentation is not a requirement but a convenience. While the WriteWhiteSpace() method allows you to explicitly create a white space in the file, the XmlTextWriter class is equipped with the Formatting property. This property is a value of the Formatting enumeration. The Formatting enumeration has two members. The Indented value ensures that each child node would be indented from its parent.

Practical Learning Practical Learning: Indenting XML Nodes
  1. Display the Central.cs file and, in the Members combo box, select mnuFileSave_Click(object sender, EventArgs e)
  2. To control the indentation when the file is saved, change the top section of the event as follows:
      
    private void mnuFileSave_Click(object sender, EventArgs e)
{
    . . . No Change

    // Find out if the user clicked OK after displaying the Save dialog box
    if (dlgSave.ShowDialog() == DialogResult.OK)
    {
        XmlTextWriter wtrRepairOrder = new XmlTextWriter(strFilename,
                    Encoding.UTF8);
        wtrRepairOrder.Formatting = Formatting.Indented;
        wtrRepairOrder.Indentation = 4;

    }

    . . . No Change
}
  3. Return to the form
  4. Click File and double-click Exit 
  5. Implement it as follows:
      
    private void mnuFileExit_Click(object sender, EventArgs e)
{
    Close();
}
  6. Execute the application
  7. Create and save a few more repair orders
  8. Close the form
 
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