Mind Boggling Serialization Problem

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When I try to load my Serialized object from a saved file it does this:

-------------------------
An unhandled exception of type
'System.Runtime.Serialization.SerializationException' occurred in
mscorlib.dll

Additional information: The constructor to deserialize an object of
type myNamespace.SmartObjects.Entry was not found.
-------------------------

Entry is another object that is called from the main object I'm trying to serialize. I have all my objects marked with <Serializable()>, it saves the object serialization flawlessly. The code errors here when I load it:

VB Code:

Dim note As Object = deserializer.Deserialize(myFileStream)

My Load Sub:

VB Code:

Public Sub Load()
            If Me.FileLocation Is Nothing Then
                MsgBox("Filelocation not set to load.")
            Else
                Dim i As Integer
                Dim deserializer As New BinaryFormatter()
                Dim myFileStream As Stream = File.OpenRead(Me.FileLocation)
                Dim tempNote As New Notebook()
                Dim ex As Exception
                Dim note As Object = deserializer.Deserialize(myFileStream)
                'ERRORS RIGHT UP THERE ^^^^
                tempNote = CType(note, Notebook)
                myFileStream.Close()
                Me.Name = tempNote.Name
                Me.FileLocation = tempNote.FileLocation
            End If
        End Sub

My Save Sub:

VB Code:

Public Sub Save()
            If Me.FileLocation Is Nothing Then
                MsgBox("Filelocation not set to save.")
            Else
                Dim myFileStream As Stream =File.Create(Me.FileLocation)
                Dim serializer As New BinaryFormatter()
                serializer.Serialize(myFileStream, Me)
                myFileStream.Close()
            End If
        End Sub

I was told this:

Quote:

Serialization can freak out at times if an object doesn't have a default constructor. I mean if the object does not have a constructor that takes no parameters.

So I added the below to all objects that didn't already have it. Still didn't work.

VB Code:

Public Sub New() 
 
End Sub

Could someone give me a specific answer? I'll post my entire namespace if i must.

Jan 6th, 2004, 08:15 AM
VBCrazyCoder

For starters, I would wrap you code in a try catch block and do a e.tostring() to get the exact error message that is occurring.

Does the class have any events? There are some issues with events and serialization too if that is the case.
Jan 6th, 2004, 03:15 PM
bergy

I did try Try and Catch and I received the same message that was listed above....

e.String = "The constructor to deserialize an object of
type myNamespace.SmartObjects.Entry was not found."

I will post my whole class for you...

full source

VB Code:

#Region "  Notebook Objects"
    <Serializable()> Public Class Notebook
        'Inherits NoteSecurity
        Private sName, sFileLocation As String
        Public AutoNumberStyle As New AutoNumberStyle()
        Public Entries As New EntryCollection()
        Public NodeCol As New Entry()
        Public Property Name() As String
            Get
                Return sName
            End Get
            Set(ByVal Value As String)
                sName = Value
            End Set
        End Property
        Public Property FileLocation() As String
            Get
                Return sFileLocation
            End Get
            Set(ByVal Value As String)
                sFileLocation = Value
            End Set
        End Property
        Public Sub Load()
            If Me.FileLocation Is Nothing Then
                MsgBox("Filelocation not set to load.")
            Else
                Dim i As Integer
                Dim deserializer As New BinaryFormatter()
                Dim myFileStream = New IO.FileStream(Me.FileLocation, IO.FileMode.Open) 'File.OpenRead(Me.FileLocation)
                Dim tempNote As New Notebook()
                Dim ex As Exception
                ' Try
                'Dim note As Object = deserializer.Deserialize(myFileStream)
                'tempNote = CType(note, Notebook)
                tempNote = deserializer.Deserialize(myFileStream)
                ' Catch ex
                ' MsgBox("An error occured while opening this file.", MsgBoxStyle.Critical, "SmarNote Error")
                '   Exit Sub
                'tempNote = CType(deserializer.Deserialize(myFileStream, Nothing), Notebook)
                ' End Try
                myFileStream.Close()
                Me.Name = tempNote.Name
                Me.FileLocation = tempNote.FileLocation
            End If
        End Sub
        Public Sub Save()
            If Me.FileLocation Is Nothing Then
                MsgBox("Filelocation not set to save.")
            Else
                Dim myFileStream As Stream = File.Create(Me.FileLocation)
                Dim serializer As New BinaryFormatter()
                myFileStream.Seek(0, SeekOrigin.Begin)
                serializer.Serialize(myFileStream, Me)
                myFileStream.Close()
            End If
        End Sub
        Public Sub New()
 
        End Sub
    End Class
 
    <Serializable()> Public Class Entry
        Inherits System.Windows.Forms.TreeNode
        Private sName As String
        Private nn As TreeNode
 
        Public Notes As New Page_Notes_Collection()
        Public KeyPoints As New Page_KeyPoints_Collection()
        Public ImpactWindows As New Page_ImpactWindow_Collection()
        Public Caselaws As New Page_CaseLaw_Collection()
        Public Property Name()
            Get
                Return sName
            End Get
            Set(ByVal Value)
                sName = Value
            End Set
        End Property
        Public Property Node() As TreeNode
            Get
                Return nn
            End Get
            Set(ByVal Value As TreeNode)
                nn = Value
            End Set
        End Property
        Public Sub New()
 
        End Sub
    End Class
 
    <Serializable()> Public Class EntryCollection
        Inherits System.Collections.CollectionBase
        Public Sub Add(ByVal awidget As Entry)
            List.Add(awidget)
        End Sub
        Public Sub Remove(ByVal index As Integer)
            If index > Count - 1 Or index < 0 Then
                System.Windows.Forms.MessageBox.Show("Index not valid!")
            Else
                List.RemoveAt(index)
            End If
        End Sub
        Public ReadOnly Property Items(ByVal index As Integer) As Entry
            Get
                Return CType(List.Item(index), Entry)
            End Get
        End Property
        Public Sub New()
 
        End Sub
    End Class
    <Serializable()> Public Class Page_CaseLaw_Collection
        Inherits System.Collections.CollectionBase
        Public Sub Add(ByVal awidget As String)
            List.Add(awidget)
        End Sub
        Public Sub Remove(ByVal index As Integer)
            If index > Count - 1 Or index < 0 Then
                System.Windows.Forms.MessageBox.Show("Index not valid!")
            Else
                List.RemoveAt(index)
            End If
        End Sub
        Public ReadOnly Property Items(ByVal index As Integer) As String
            Get
                Return CType(List.Item(index), String)
            End Get
        End Property
        Public Sub New()
 
        End Sub
    End Class
    <Serializable()> Public Class Page_ImpactWindow_Collection
        Inherits System.Collections.CollectionBase
        Public Sub Add(ByVal awidget As String)
            List.Add(awidget)
        End Sub
        Public Sub Remove(ByVal index As Integer)
            If index > Count - 1 Or index < 0 Then
                System.Windows.Forms.MessageBox.Show("Index not valid!")
            Else
                List.RemoveAt(index)
            End If
        End Sub
        Public ReadOnly Property Items(ByVal index As Integer) As String
            Get
                Return CType(List.Item(index), String)
            End Get
        End Property
        Public Sub New()
 
        End Sub
    End Class
    <Serializable()> Public Class Page_Notes_Collection
        Inherits System.Collections.CollectionBase
        Public Sub Add(ByVal awidget As String)
            List.Add(awidget)
        End Sub
        Public Sub Remove(ByVal index As Integer)
            If index > Count - 1 Or index < 0 Then
                System.Windows.Forms.MessageBox.Show("Index not valid!")
            Else
                List.RemoveAt(index)
            End If
        End Sub
        Public ReadOnly Property Items(ByVal index As Integer) As String
            Get
                Return CType(List.Item(index), String)
            End Get
        End Property
        Public Sub New()
 
        End Sub
    End Class
    <Serializable()> Public Class Page_KeyPoints_Collection
        Inherits System.Collections.CollectionBase
        Public Sub Add(ByVal awidget As String)
            List.Add(awidget)
        End Sub
        Public Sub Remove(ByVal index As Integer)
            If index > Count - 1 Or index < 0 Then
                System.Windows.Forms.MessageBox.Show("Index not valid!")
            Else
                List.RemoveAt(index)
            End If
        End Sub
        Public ReadOnly Property Items(ByVal index As Integer) As String
            Get
                Return CType(List.Item(index), String)
            End Get
        End Property
        Public Sub New()
 
        End Sub
    End Class
#End Region

Jan 6th, 2004, 03:26 PM
Edneeis

Whats the AutoNumberStyle object?

I think it is because the Entry object also has a TreeNode object as a property. I don't think a TreeNode is serializable which means that property can't be serialized. Why have a proeprty of an object that inherits from TreeNode be a TreeNode?

Nevermind I spoke too soon. Although it definately has something to do with the TreeNode since if it doesn't inherit from it then it works fine.

I came across this: http://www.dotnet247.com/247reference/msgs/6/31186.aspx

The wierd thing is that you can serialize a TreeNode as a property just fine even if it has multiple sub nodes. You just can't serialize a class that derives from a TreeNode.
Jan 10th, 2004, 04:07 PM
bergy

thanks!

Ed thanks so much for solving my weird issue, everything works out great now, thanks alot for the link!