DeSerialization of an XML Stream

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RSH - 14 Jun 2007 22:23 GMT

Hi,

I have a situation where I am serializing a custom object into an XML string
that is stored on a Session variable.

The problem is I can't seem to figure out how to get it back to an object.

Serialization:
' WORKS FINE

Public Function SerializeObject(ByVal obj As CompanyBase)

Dim oXS As XmlSerializer = New XmlSerializer(obj.GetType)

Dim oStrW As New StringWriter

Dim sXML As String

oXS.Serialize(oStrW, obj)

sXML = oStrW.ToString()

oStrW.Close()

Return sXML

End Function

' GENERATES AN 'ILLEGAL CHARACTERS EXCEPTION

' str is the XML string created by the function above

Public Function DeserializeObject(ByVal str As String) As CompanyBase

Dim oCompanyBase As CompanyBase = New CompanyBase

Dim oXS As XmlSerializer = New XmlSerializer(oCompanyBase.GetType) <-------
Is there a way to not have to instantiate oCompany just to get at the type?

Dim oStmR As StreamReader

oStmR = New StreamReader(str)

oCompanyBase = CType(oXS.Deserialize(oStmR), CompanyBase)

oStmR.Close()

Return oCompanyBase

End Function

Thanks!

Ron

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Milosz Skalecki [MCAD] - 14 Jun 2007 23:37 GMT

Hi there,

In this case i would implement ISerializable interface within the
CompantBase class:

-- begin CompanyBase.vb --

Imports System.Runtime.Serialization

Public Class CompanyBase
    Implements ISerializable

    Public Sub New()

    End Sub

    Private Sub New(ByVal info As SerializationInfo, ByVal context As
StreamingContext)
        Me._companyName = info.GetString("CompanyName")
        Me._employeeCount = info.GetInt32("EmployeeCount")
    End Sub

    Public Sub GetObjectData( _
    ByVal info As SerializationInfo, _
    ByVal context As StreamingContext) _
    Implements ISerializable.GetObjectData
        info.AddValue("CompanyName", Me.CompanyName)
        info.AddValue("EmployeeCount", Me.EmployeeCount)
    End Sub

    Private _companyName As String
    Public Property CompanyName() As String
        Get
            Return _companyName
        End Get
        Set(ByVal value As String)
            _companyName = value
        End Set
    End Property

    Private _employeeCount As Integer
    Public Property EmployeeCount() As Integer
        Get
            Return _employeeCount
        End Get
        Set(ByVal value As Integer)
            _employeeCount = value
        End Set
    End Property

End Class

-- end CompanyBase.vb --

or simply mark your class with Serializable attribute:
<Serializable()> _
Public Class CompanyBase
...
end class

and then de/serialize like this

-- begin default.aspx --

Protected Sub Page_Load(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles Me.Load

    Dim xml As String
    Dim company As CompanyBase
    Dim serializer As New _
    System.Xml.Serialization.XmlSerializer( _
    GetType(CompanyBase), _
    "http://companyBase")

    If IsPostBack Then

        xml = Session("companyData")

        Using reader As New System.IO.StringReader(xml)
            company = CType(serializer.Deserialize(reader), _
                CompanyBase)
        End Using

    Else

        company = New CompanyBase()
        company.CompanyName = "Microsoft"
        company.EmployeeCount = 1200

        Using writter As New System.IO.StringWriter()
            serializer.Serialize(writter, company)
            writter.Flush()
            xml = writter.ToString()
        End Using

        Session("companyData") = xml

    End If

end sub
-- end default.aspx --

Hope this helps
vb.net sucks ;-)

Signature

Milosz

> Hi,
>
[quoted text clipped - 50 lines]
>
> Ron

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DeSerialization of an XML Stream

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