Microsoft Visual Basic Example Application: Altair Realtors

	Example Application: Altair Realtors

Introduction

Altair Realtors is a fictitious real estate companies that sells different types of properties, including single families, townhouses (or town homes), and condominiums. This application is mainly used to present some of the available properties to a potential customer.

An XML attribute is a sub-element that is created as part of a parent element. This application is used to explore the techniques of managing XML attributes.

Practical Learning: Creating the Application

Start Microsoft Visual Basic and create a Windows Application named AltairRealtors1
To create a new form, on the main menu, click Projects -> Add Windows Form...
Set the Name to PropertyEditor and click Add

Design the form as follows:

Control	Text	Name	Other Properties
Label	Property Code:
TextBox		txtPropertyCode	Modifiers: Public
Label	Status
ComboBox		cbxStatus	Modifiers: Public Items: Sold Available Needs Repair
Label
DateTimePicker		dtpDateListed	Modifiers: Public Format: Short
Label	Year Built:
TextBox		txtYearBuilt
Label	Property Type:
ComboBox		cbxPropertyTypes	Modifiers: Public Items: Unknown Single Family Townhouse Condominium
Label	Style:
ComboBox		cbxStyles	Modifiers: Public Items: Farm Colonial Victorian Contemporary
Label	Address:
TextBox		txtAddress	Modifiers: Public
Label	City:
TextBox		txtCity	Modifiers: Public
Label	Location:
TextBox		txtLocation	Modifiers: Public
Label	State:
ComboBox		cbxStates	Modifiers: Public Items: DC MD PA VA WV
Label	ZIP Code:
TextBox		txtZIPCode	Modifiers: Public
Label	Stories
TextBox	0	txtStories	Modifiers: Public
Label	Bedrooms:
TextBox	0	txtBedrooms	Modifiers: Public
Label	Bathrooms:
TextBox	0.0	txtBathrooms	Modifiers: Public
Label	Condition:
ComboBox		cbxConditions	Modifiers: Public Items: Good Excellent Needs Repairs
Label	Market Value:
TextBox	0.00	txtMarketValue	Modifiers: Public
Label	Picture Path:
TextBox		txtPicturePath	Modifiers: Public Enabled: False
Button	Select Picture...	btnPicture
PictureBox		pbxProperty	Modifiers: Public SizeMode: Zoom
Button	OK	btnOK	DialogResult: OK
Button	Cancel	btnCancel	DialogResult: Cancel
OpenFileDialog	(Name): dlgPicture Title: Select Property Picture DefaultExt: jpg Filter: JPEG Files (.jpg,.jpeg)\|.jpg\|GIF Files (.gif)\|.gif\|Bitmap Files (.bmp)\|.bmp\|PNG Files (.png)\|*.png

Form

FormBorderStyle:

FixedDialog

Text:

Altair Realtors - Property Editor

StartPosition:

CenterScreen

AcceptButton:

btnOK

CancelButton:

btnCancel

MaximizeBox:

False

MinimizeBox:

False

ShowInTaskBar:

False

Double-click the Select Picture button and implement its event as follows:

Private Sub btnPicture_Click(ByVal sender As System.Object, _
                                 ByVal e As System.EventArgs) _
                                 Handles btnPicture.Click
        If dlgPicture.ShowDialog() = DialogResult.OK Then
            txtPicturePath.Text = dlgPicture.FileName
            pbxProperty.Image = Image.FromFile(txtPicturePath.Text)
        End If
End Sub

In the Solution Explorer, right-click Form1.vb and click Rename
Type RealEstate.vb and press Enter twice (to display that form)
From the Toolbox, add a ListView to the form

While the new list view is still selected, in the Properties window, click the ellipsis button of the Columns field and create the columns as follows:

(Name)	Text	TextAlign	Width
colIndex	#		40
colPropertyCode	Prop Code	Center	65
colPropertyType	Property Type		80
colPropertyCondition	Condition		65
colLocation	Location		70
colStories	Stories	Right	45
colBedrooms	Bedrooms	Right	62
colBathrooms	Bathrooms	Right	62
colMarketValue	Market Value	Right	75

Design the form as follows:

Control	Text	Name	Other Properties
ListView		lvwAllocations	View: Details GridLines: True FullRowSelect: True Anchor: Top, Bottom, Left, Right
PictureBox		pbxProperty	Anchor: Bottom, Left
Label	Description		Anchor: Bottom, Right
TextBox		txtDescription	Multiline: True Anchor: Bottom, Right
Button	New Property...	btnNewProperty	Anchor: Bottom, Right
Button	Close	btnClose	Anchor: Bottom, Right

Right-click the form and click View Code

Above the Public Class line, add the following lines

Imports System.IO
Imports System.Xml

Public Class RealEstate

End Class

In the Class Name combo box, select btnNewProperty

In the Method Name combo box, select Click and implement the event as follows:

Imports System.IO
Imports System.Xml

Public Class RealEstate

    Private Sub btnNewProperty_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnNewProperty.Click
        ' Get a reference to the property editor
        Dim Editor As PropertyEditor = New PropertyEditor
        Dim Filename As String = "properties.xml"

        If Editor.ShowDialog() = DialogResult.OK Then
            Dim PropertyType As String, Location As String
            Dim Stories As Integer, Bedrooms As Integer
            Dim Bathrooms As Single
            Dim MarketValue As Double

            ' We will need a reference to the XML document
            Dim DOMProperties As XmlDocument = New XmlDocument

            ' Find out if the file exists already
            ' If it doesn't, then create it
            If Not File.Exists(Filename) Then
                DOMProperties.LoadXml( _
			"<?xml version=""1.0"" encoding=""utf-8""?>" & _
                                      "<Listing></Listing>")
                DOMProperties.Save(Filename)
            End If

            ' Open the XML file
            DOMProperties.Load(Filename)

            ' Get a reference to the root node
            Dim RootElement As XmlElement = DOMProperties.DocumentElement

            PropertyType = Editor.cbxPropertyTypes.Text
            Location = Editor.txtLocation.Text
            Stories = CInt(Editor.txtStories.Text)
            Bedrooms = CInt(Editor.txtBedrooms.Text)
            Bathrooms = CSng(Editor.txtBathrooms.Text)
            MarketValue = CDbl(Editor.txtMarketValue.Text)

            ' Create a node named Property
            Dim PropertyElement As XmlElement = _
		DOMProperties.CreateElement("Property")
            ' Add it to the root element
            RootElement.AppendChild(PropertyElement)

            ' Create a node named PropertyType
            PropertyElement = DOMProperties.CreateElement("PropertyType")
            Dim TextProperty As XmlText = _
		DOMProperties.CreateTextNode(PropertyType)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Location
            PropertyElement = DOMProperties.CreateElement("Location")
            TextProperty = DOMProperties.CreateTextNode(Location)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Stories
            PropertyElement = DOMProperties.CreateElement("Stories")
            TextProperty = DOMProperties.CreateTextNode(Stories.ToString())
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Bedrooms
            PropertyElement = DOMProperties.CreateElement("Bedrooms")
            TextProperty = DOMProperties.CreateTextNode(Bedrooms.ToString())
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Bathrooms
            PropertyElement = DOMProperties.CreateElement("Bathrooms")
            TextProperty = _
		DOMProperties.CreateTextNode(Bathrooms.ToString("F"))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named MarketValue
            PropertyElement = DOMProperties.CreateElement("MarketValue")
            TextProperty = _
		DOMProperties.CreateTextNode(MarketValue.ToString("F"))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Save the XML file
            DOMProperties.Save(Filename)
        End If
    End Sub
End Class

Execute the application
Click the New Property button

Enter the following pieces of information:

Property Type	Single Family
Location	White Oak
Stories	2
Bedrooms	3
Bathrooms	2.5
Market Value	465580

Click OK
Close the form and return to your programming environment

From the main menu of Visual Studio, open the properties.xml file from the AltairRealtors1\AltairRealtors\bin\Debug folder:

<?xml version="1.0" encoding="utf-8"?>
<Listing>
  <Property>
    <PropertyType>Single Family</PropertyType>
    <Location>White Oak</Location>
    <Stories>2</Stories>
    <Bedrooms>3</Bedrooms>
    <Bathrooms>2.50</Bathrooms>
    <MarketValue>365580.00</MarketValue>
  </Property>
</Listing>

Display the RealEstate.vb file

To set attributes of a node, change the file as follows:

Imports System.IO
Imports System.Xml

Public Class RealEstate

    Private Sub btnNewProperty_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnNewProperty.Click
        ' Get a reference to the property editor
        Dim Editor As PropertyEditor = New PropertyEditor

        Dim Filename As String = "properties.xml"

        Dim RndNumber As Random = New Random
        Editor.txtPropertyCode.Text = RndNumber.Next(100, 999).ToString() & _
                                      "-" & RndNumber.Next(100, 999)

        If Editor.ShowDialog() = DialogResult.OK Then
            Dim PropertyCode As String
            Dim PropertyType As String
            Dim Location As String
            Dim SaleStatus As String
            Dim Stories As Integer, Bedrooms As Integer
            Dim Bathrooms As Single
            Dim MarketValue As Double

            ' We will need a reference to the XML document
            Dim DOMProperties As XmlDocument = New XmlDocument

            ' Find out if the file exists already
            ' If it doesn't, then create it
            If Not File.Exists(Filename) Then
                DOMProperties.LoadXml( _
			"<?xml version=""1.0"" encoding=""utf-8""?>" & _
                                  "<Listing></Listing>")
                DOMProperties.Save(Filename)
            End If

            ' Open the XML file
            DOMProperties.Load(Filename)

            PropertyCode = Editor.txtPropertyCode.Text
            SaleStatus = Editor.cbxStatus.Text
            PropertyType = Editor.cbxPropertyTypes.Text
            Location = Editor.txtLocation.Text
            Stories = CInt(Editor.txtStories.Text)
            Bedrooms = CInt(Editor.txtBedrooms.Text)
            Bathrooms = CSng(Editor.txtBathrooms.Text)
            MarketValue = CDbl(Editor.txtMarketValue.Text)

            ' Get a reference to the root element
            Dim RootElement As XmlElement = DOMProperties.DocumentElement
            ' Create a node named Property
            Dim PropertyElement As XmlElement = _
		DOMProperties.CreateElement("Property")

            ' Create an attribute for the Propety node
            PropertyElement.SetAttribute("Code", PropertyCode)

            ' Create an attribute for the Propety node
            PropertyElement.SetAttribute("Status", SaleStatus)

            ' Add it to the root element
            RootElement.AppendChild(PropertyElement)

            . . . No Change

            ' Save the XML file
            DOMProperties.Save(Filename)
        End If
    End Sub
End Class

Execute the application
Click the New Property button

Enter the following pieces of information:

Status	Sold
Property Type	Single Family
Location	Arlington Cemetery
Stories	3
Bedrooms	5
Bathrooms	3.5
Market Value	675880

Click OK
Close the form and return to your programming environment

In Visual Studio, access the properties.xml tab to see the file (the value of the Code attribute will be different from yours):

<?xml version="1.0" encoding="utf-8"?>
<Listing>
  <Property>
    <PropertyType>Single Family</PropertyType>
    <Location>White Oak</Location>
    <Stories>2</Stories>
    <Bedrooms>3</Bedrooms>
    <Bathrooms>2.50</Bathrooms>
    <MarketValue>365580.00</MarketValue>
  </Property>
  <Property Code="700-326" Status="Sold">
    <PropertyType>Single Family</PropertyType>
    <Location>Arlington Cemetery</Location>
    <Stories>3</Stories>
    <Bedrooms>5</Bedrooms>
    <Bathrooms>3.50</Bathrooms>
    <MarketValue>675880.00</MarketValue>
  </Property>
</Listing>

Display the RealEstate.vb file

To add a few attributes, change the file as follows:

Imports System.IO
Imports System.Xml

Public Class RealEstate

    Private Sub btnNewProperty_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnNewProperty.Click
        ' Get a reference to the property editor
        Dim Editor As PropertyEditor = New PropertyEditor
        ' If this directory doesn't exist, create it
        Directory.CreateDirectory("C:\Altair Realtors")
        ' This is the XML file that holds the list of proeprties
        Dim Filename As String = "C:\Altair Realtors\properties.xml"

        Dim RndNumber As Random = New Random
        Editor.txtPropertyCode.Text = RndNumber.Next(100, 999) & _
                                  "-" & RndNumber.Next(100, 999).ToString()

        If Editor.ShowDialog() = DialogResult.OK Then
            Dim PropertyCode As String, PropertyType As String
            Dim Location As String, SaleStatus As String
            Dim Style As String, Condition As String
            Dim YearBuilt As Integer, Stories As Integer
	    Dim Bedrooms As Integer
            Dim Bathrooms As Single
            Dim MarketValue As Double

            ' We will need a reference to the XML document
            Dim DOMProperties As XmlDocument = New XmlDocument

            ' Find out if the file exists already
            ' If it doesn't, then create it
            If Not File.Exists(Filename) Then
                DOMProperties.LoadXml( _
			"<?xml version=""1.0"" encoding=""utf-8""?>" & _
                                      "<Listing></Listing>")
                DOMProperties.Save(Filename)
            End If

            ' Open the XML file
            DOMProperties.Load(Filename)

            PropertyCode = Editor.txtPropertyCode.Text
            Location = Editor.txtLocation.Text
            SaleStatus = Editor.cbxStatus.Text
            YearBuilt = CInt(Editor.txtYearBuilt.Text)
            PropertyType = Editor.cbxPropertyTypes.Text
            Style = Editor.cbxStyle.Text
            Condition = Editor.cbxConditions.Text
            Bedrooms = CInt(Editor.txtBedrooms.Text)
            Bathrooms = CSng(Editor.txtBathrooms.Text)
            MarketValue = CDbl(Editor.txtMarketValue.Text)

            ' Get a reference to the root element
            Dim RootElement As XmlElement = DOMProperties.DocumentElement
            ' Create a node named Property
            Dim PropertyElement As XmlElement = _
		DOMProperties.CreateElement("Property")

            ' Create an attribute for the Propety node
            PropertyElement.SetAttribute("Code", PropertyCode)

            ' Create an attribute for the Propety node
            PropertyElement.SetAttribute("Status", SaleStatus)
            ' Add it to the root element
            RootElement.AppendChild(PropertyElement)

            ' Create a node named Property
            PropertyElement = DOMProperties.CreateElement("DateListed")
            RootElement.LastChild.AppendChild(PropertyElement)

            ' Create an attribute for the DateListed element
            Dim atrProperty As XmlAttribute = _
		DOMProperties.CreateAttribute("YearBuilt")
            atrProperty.Value = YearBuilt
            PropertyElement.SetAttributeNode(atrProperty)

            ' Create a node named PropertyType
            PropertyElement = DOMProperties.CreateElement("PropertyType")
            Dim TextProperty As XmlText = _
		DOMProperties.CreateTextNode(PropertyType)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create an attribute for the PropertyType element
            atrProperty = DOMProperties.CreateAttribute("Style")
            atrProperty.Value = Style
            PropertyElement.SetAttributeNode(atrProperty)

            ' Create an attribute for the Condition element
            atrProperty = DOMProperties.CreateAttribute("Condition")
            atrProperty.Value = Condition
            PropertyElement.SetAttributeNode(atrProperty)

            ' Create a node named Location
            PropertyElement = DOMProperties.CreateElement("Location")
            TextProperty = DOMProperties.CreateTextNode(Location)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Stories
            PropertyElement = DOMProperties.CreateElement("Stories")
            TextProperty = DOMProperties.CreateTextNode(Stories)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Bedrooms
            PropertyElement = DOMProperties.CreateElement("Bedrooms")
            TextProperty = DOMProperties.CreateTextNode(Bedrooms)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Bathrooms
            PropertyElement = DOMProperties.CreateElement("Bathrooms")
            TextProperty = _
		DOMProperties.CreateTextNode(FormatNumber(Bathrooms))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named MarketValue
            PropertyElement = DOMProperties.CreateElement("MarketValue")
            TextProperty = _
		DOMProperties.CreateTextNode(FormatNumber(MarketValue))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Save the XML file
            DOMProperties.Save(Filename)
        End If
    End Sub
End Class

Save the file

To add a few attributes, change the file as follows:

Imports System.IO
Imports System.Xml

Public Class RealEstate

    Private Sub btnNewProperty_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnNewProperty.Click
        ' Get a reference to the property editor
        Dim Editor As PropertyEditor = New PropertyEditor
        ' If this directory doesn't exist, create it
        Dim strDirectory As String = "C:\Altair Realtors"
        Directory.CreateDirectory(strDirectory)
        ' This is the XML file that holds the list of proeprties
        Dim Filename As String = "C:\Altair Realtors\properties.xml"

        Dim RndNumber As Random = New Random
        Editor.txtPropertyCode.Text = RndNumber.Next(100, 999) & _
                                      "-" & RndNumber.Next(100, 999)
        Dim strPicturePath As String

        If Editor.ShowDialog() = DialogResult.OK Then
            Dim PropertyCode As String, PropertyType As String
            Dim Location As String, SaleStatus As String
            Dim Style As String, Condition As String
            Dim Address As String, City As String, State As String
            Dim ZIPCode As String, Description As String
            Dim DateListed As Date
            Dim YearBuilt As Integer, Stories As Integer, Bedrooms As Integer
            Dim Bathrooms As Single
            Dim MarketValue As Double

            ' We will need a reference to the XML document
            Dim DOMProperties As XmlDocument = New XmlDocument

            ' Find out if the file exists already
            ' If it doesn't, then create it
            If Not File.Exists(Filename) Then
                DOMProperties.LoadXml( _
			"<?xml version=""1.0"" encoding=""utf-8""?>" & _
                                      "<Listing></Listing>")
                DOMProperties.Save(Filename)
            End If

            ' Open the XML file
            DOMProperties.Load(Filename)

            PropertyCode = Editor.txtPropertyCode.Text
            SaleStatus = Editor.cbxStatus.Text
            DateListed = Editor.dtpDateListed.Value
            YearBuilt = CInt(Editor.txtYearBuilt.Text)
            PropertyType = Editor.cbxPropertyTypes.Text
            Style = Editor.cbxStyle.Text
            Condition = Editor.cbxConditions.Text
            Location = Editor.txtLocation.Text
            Address = Editor.txtAddress.Text
            City = Editor.txtCity.Text
            State = Editor.cbxStates.Text
            ZIPCode = Editor.txtZIPCode.Text
            Stories = CInt(Editor.txtStories.Text)
            Bedrooms = CInt(Editor.txtBedrooms.Text)
            Bathrooms = CSng(Editor.txtBathrooms.Text)
            Description = Editor.txtDescription.Text
            MarketValue = CDbl(Editor.txtMarketValue.Text)
            strPicturePath = Editor.txtPicturePath.Text

            ' Get a reference to the root element
            Dim RootElement As XmlElement = DOMProperties.DocumentElement
            ' Create a node named Property
            Dim PropertyElement As XmlElement = _
		DOMProperties.CreateElement("Property")

            ' Create an attribute for the Propety node
            PropertyElement.SetAttribute("Code", PropertyCode)

            ' Create an attribute for the Propety node
            PropertyElement.SetAttribute("Status", SaleStatus)
            ' Add it to the root element
            RootElement.AppendChild(PropertyElement)

            ' Create a node named Property
            PropertyElement = DOMProperties.CreateElement("DateListed")
            Dim TextProperty As XmlText = _
		DOMProperties.CreateTextNode(DateListed.ToString("d"))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)
            RootElement.LastChild.AppendChild(PropertyElement)

            ' Create an attribute for the DateListed element
            Dim atrProperty As XmlAttribute = _
		DOMProperties.CreateAttribute("YearBuilt")
            atrProperty.Value = YearBuilt
            PropertyElement.SetAttributeNode(atrProperty)

            ' Create a node named PropertyType
            PropertyElement = DOMProperties.CreateElement("PropertyType")
            TextProperty = DOMProperties.CreateTextNode(PropertyType)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create an attribute for the PropertyType element
            atrProperty = DOMProperties.CreateAttribute("Style")
            atrProperty.Value = Style
            PropertyElement.SetAttributeNode(atrProperty)

            ' Create an attribute for the PropertyType element
            atrProperty = DOMProperties.CreateAttribute("Condition")
            atrProperty.Value = Condition
            PropertyElement.SetAttributeNode(atrProperty)

            ' Create a node named Location
            PropertyElement = DOMProperties.CreateElement("Location")
            TextProperty = DOMProperties.CreateTextNode(Location)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create some attributes for the Location element
            atrProperty = DOMProperties.CreateAttribute("Address")
            atrProperty.Value = Address
            PropertyElement.Attributes.Append(atrProperty)

            atrProperty = DOMProperties.CreateAttribute("City")
            atrProperty.Value = City
            PropertyElement.Attributes.Append(atrProperty)

            atrProperty = DOMProperties.CreateAttribute("State")
            atrProperty.Value = State
            PropertyElement.Attributes.Append(atrProperty)

            atrProperty = DOMProperties.CreateAttribute("ZIPCode")
            atrProperty.Value = ZIPCode
            PropertyElement.Attributes.Append(atrProperty)

            ' Create a node named Stories
            PropertyElement = DOMProperties.CreateElement("Stories")
            TextProperty = DOMProperties.CreateTextNode(Stories.ToString())
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Bedrooms
            PropertyElement = DOMProperties.CreateElement("Bedrooms")
            TextProperty = DOMProperties.CreateTextNode(Bedrooms.ToString())
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Bathrooms
            PropertyElement = DOMProperties.CreateElement("Bathrooms")
            TextProperty = _
		DOMProperties.CreateTextNode(FormatNumber(Bathrooms))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named MarketValue
            PropertyElement = DOMProperties.CreateElement("MarketValue")
            TextProperty = _
		DOMProperties.CreateTextNode(FormatNumber(MarketValue))
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Create a node named Description
            PropertyElement = DOMProperties.CreateElement("Description")
            TextProperty = DOMProperties.CreateTextNode(Description)
            RootElement.LastChild.AppendChild(PropertyElement)
            RootElement.LastChild.LastChild.AppendChild(TextProperty)

            ' Save the XML file
            DOMProperties.Save(Filename)

            If strPicturePath.Length <> 0 Then
                ' The following code gets a reference to the picture's name 
                Dim flePicture As FileInfo = New FileInfo(strPicturePath)
                ' Then it copies it to the directory of this business
                ' It changes its name to be the same as the property code
                flePicture.CopyTo("C:\Altair Realtors\" & _
                                  PropertyCode & _
                                  flePicture.Extension)
            End If

            ShowListing()

            If lvwProperties.Items.Count > 0 Then
                lvwProperties.Items(0).Selected = True
            End If
        End If
    End Sub

    Private Sub ShowListing()

    End Sub
End Class

Execute the application and create a few properties
Close the form and return to your programming environment

Practical Learning: Accessing XML Attributes

Implement the ShowListing procedure as follows:

Private Sub ShowListing()
        Dim DOMProperties As XmlDocument = New XmlDocument
        Dim Filename As String = "C:\Altair Realtors\properties.xml"

        If File.Exists(Filename) Then
            lvwProperties.Items.Clear()

            DOMProperties.Load(Filename)
            Dim PropertyElement As XmlElement = DOMProperties.DocumentElement
            Dim ListOfProperties As XmlNodeList = PropertyElement.ChildNodes

            Dim i As Integer = 1

            For Each Node As XmlNode In ListOfProperties
                Dim lviProperty As ListViewItem = New ListViewItem(i)

                lviProperty.SubItems.Add(Node.Attributes(0).InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.Attributes(1).InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.NextSibling.InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.NextSibling.NextSibling.InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.NextSibling.NextSibling.NextSibling.InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText)
                lviProperty.SubItems.Add(Node.FirstChild.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText)
                lvwProperties.Items.Add(lviProperty)
                i = i + 1
            Next

            txtDescription.Text = ListOfProperties(0)("Description").InnerText
        End If
End Sub

In the Class Name combo box, select (RealEstate Events)

In the Method Name combo box, select Load and implement the event as follows:

Private Sub RealEstate_Load(ByVal sender As Object, _
                                ByVal e As System.EventArgs) _
                                Handles Me.Load
        ShowListing()

        If lvwProperties.Items.Count > 0 Then
            lvwProperties.Items(0).Selected = True
        End If
End Sub

In the Class name combo box, select lvwProperties

In the Method Name combo box, select SelectedIndexChanged and implement the event as follows:

Private Sub lvwProperties_SelectedIndexChanged(ByVal sender As Object, _
                                               ByVal e As System.EventArgs) _
                                      Handles lvwProperties.SelectedIndexChanged
    If (lvwProperties.SelectedItems.Count = 0) Or _
       (lvwProperties.SelectedItems.Count > 1) Then
        Exit Sub
    End If

    Dim PropertyCode As String = lvwProperties.SelectedItems(0).SubItems(1).Text

    ' Make a list of the picture files
    Dim strDirectory As String = "C:\Altair Realtors"
    Dim dirProperties As DirectoryInfo = New DirectoryInfo(strDirectory)
    Dim PictureFiles() As FileInfo = dirProperties.GetFiles()

    ' Look for a file that holds the same name as the item number
    For Each fle As FileInfo In PictureFiles
        ' Get the name of the file without its extension
        Dim fwe As String = Path.GetFileNameWithoutExtension(fle.FullName)
         If fwe = PropertyCode Then
            pbxProperty.Image = Image.FromFile(strDirectory & _
                  "\" & PropertyCode + fle.Extension)
        End If
    Next

    Dim DOMProperties As XmlDocument = New XmlDocument
    Dim Filename As String = "C:\Altair Realtors\properties.xml"

    If File.Exists(Filename) Then
        DOMProperties.Load(Filename)
        Dim PropertyElement As XmlElement = DOMProperties.DocumentElement
        Dim ListOfProperties As XmlNodeList = PropertyElement.ChildNodes

        For Each Node As XmlNode In ListOfProperties
            If Node.Attributes(0).InnerText = PropertyCode Then
                txtDescription.Text = Node("Description").InnerText
            End If
        Next
    End If
End Sub

In the Class Name combo box, select btnClose

In the Method Name combo box, select Click and implement the event as follows:

Private Sub btnClose_Click(ByVal sender As Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnClose.Click
        End
End Sub

Execute the application

Exercises

Altair Realtors

Create a Windows Application named AltairRealtors1a following the same steps as this lesson
Create big pictures of the properties (houses) and save them
Configure the first form so that, if the user double-clicks the picture, another window opens and displays a bigger picture of the house or of the building
Configure the first form so that, if the user double-clicks an item, the property editor opens and displays the corresponding property. Then, if the user modifies a value in the dialog box and clicks OK, you update the same property with the changed value(s)

Make the necessary changes to the application to produce an XML document with the following additional elements and attributes

<Listing>
    <Property Code"000-000" Status="">
        <DateListed YearBuilt=""></DateListed>
        <PropertyType Style="" Condition=""></PropertyType>
        <Location Address="" City="" State="" ZIPCode=""></Location>
        <Stories></Stories>
        <Bedrooms UpperFloor="4" LowerFloor="0" Basement="1">5</Bedrooms>
        <Bathrooms UpperFloor="2" LowerFloor="0.5" Basement="1">3.5</Bathrooms>
        <IndoorGarage Spaces="2">true</IndoorGarage>
        <FinishedBasement Entrance="Common/Rear" FinishedType="Recreation Room/Apartment">true</FinishedBasement>
        <Description></Description>
    </Property>
</Listing>


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