<%@ Page language="vb" %>
<%@ Import Namespace="System.Data" %>
Dim xmlPath As String
Dim cat As catalog
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
xmlPath = Server.MapPath("cdcatalog.xml")
If cat Is Nothing Then
cat = LoadData(xmlPath)
Dim cd As catalogCD
For Each cd In cat.Items
titleDropDownList.Items.Add(New System.Web.UI.WebControls.ListItem(cd.title))
Next cd
End If
End Sub
Private Function LoadData(ByVal path As String) As catalog
Try
Dim fs As System.IO.FileStream = System.IO.File.OpenRead(path)
Dim buff(fs.Length) As Byte
fs.Read(buff, 0, CInt(fs.Length))
fs.Close()
cat = CType(Serialization.DeSerializeXML(System.Text.ASCIIEncoding.ASCII.GetString(buff), GetType(catalog)), catalog)
Return cat
Catch
End Try
End Function 'LoadData
Private Sub titleDropDownList_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim findvalue As String = titleDropDownList.SelectedItem.Text
Dim cd As catalogCD
For Each cd In cat.Items
If cd.title = findvalue Then
artistTextBox.Text = cd.artist
countryTextBox.Text = cd.country
companyTextBox.Text = cd.company
priceTextBox.Text = cd.price
yearTextBox.Text = cd.year
Exit For
End If
Next cd
End Sub
Private Sub SaveButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim findvalue As String = titleDropDownList.SelectedItem.Text
Dim foundcd As catalogCD = Nothing
Dim cd As catalogCD
For Each cd In cat.Items
If cd.title = findvalue Then
foundcd = cd
Exit For
End If
Next cd
If Not (foundcd Is Nothing) Then
foundcd.artist = artistTextBox.Text
foundcd.country = countryTextBox.Text
foundcd.company = companyTextBox.Text
foundcd.price = priceTextBox.Text
foundcd.year = yearTextBox.Text
Dim data As System.IO.MemoryStream = Serialization.SerializeXML(cat, GetType(catalog))
Dim databytes As Byte() = data.ToArray()
If System.IO.File.Exists(xmlPath) Then
System.IO.File.Delete(xmlPath)
End If
Dim f As System.IO.FileStream = System.IO.File.OpenWrite(xmlPath)
f.Write(databytes, 0, databytes.Length)
f.Close()
End If
End Sub
Public Class Serialization
Public Shared Function SerializeXML(ByVal request As Object, ByVal type As System.Type) As System.IO.MemoryStream
Try
Dim serializer As New System.Xml.Serialization.XmlSerializer(type)
Dim stm As New System.IO.MemoryStream()
serializer.Serialize(stm, request)
Return stm
Catch e As Exception
Return Nothing
End Try
End Function 'SerializeXML
Public Shared Function DeSerializeXML(ByVal envelope As String, ByVal type As System.Type) As Object
Try
Dim serializer As New System.Xml.Serialization.XmlSerializer(type)
Dim stm As New System.IO.MemoryStream(System.Text.Encoding.ASCII.GetBytes(envelope))
Dim ud As Object = serializer.Deserialize(stm)
stm.Close()
Return ud
Catch e As Exception
Return Nothing
End Try
End Function 'DeSerializeXML
End Class 'Serialization
_
Public Class catalog
_
Public Items() As catalogCD
End Class
Public Class catalogCD
Public title As String
Public artist As String
Public country As String
Public company As String
Public price As String
Public year As String
End Class
Creating a Class from an XML Document
Title:
Artist:
Country:
Company:
Price:
Year: