Serialization problem

30 Nov 2006 12:34 PM

Norman Chong

Hiddeldi ho,

I want to save an object so that I can use its content after I restart
my program. I tried to solve this with serialization because someone
told me that this is the correct way for this.
So I wrote the following code to serialize\deserialize the object, but
now I have the problem that the object has a generic list and when I'm
trying to deserialize it, I get an error.

<System.Serializable()> Public Class TestClass
    Implements Runtime.Serialization.ISerializable
Private lstContent As List(Of Object)

    Public Sub New(ByVal info As Serialization.SerializationInfo, ByVal
context As Serialization.StreamingContext) Implements
Serialization.ISerializable.GetObjectData
        lstContent = CType(info.GetValue("MyList", lstContent.GetType),
List(Of Object))
    End Sub

    Public Sub GetObjectData(ByVal info As
Serialization.SerializationInfo, ByVal context As
Serialization.StreamingContext) Implements
Serialization.ISerializable.GetObjectData
        info.addValue("MyList",lstContent)
    End Sub

    Public Sub Serialize()
        Dim fs As New IO.FileStream("DataFile.dat", IO.FileMode.Create)
        ' Construct a BinaryFormatter and use it to serialize the data
to the stream.
        Dim formatter As New
Runtime.Serialization.Formatters.Binary.BinaryFormatter
        Try
            formatter.Serialize(fs, Me)
        Catch e As Runtime.Serialization.SerializationException
            MessageBox.Show("Failed to serialize. Reason: " &
e.Message)
            Throw
        Finally
            fs.Close()
        End Try
    End Sub

    Public Shared Function Deserialize() As TestClass
        Dim fs As New IO.FileStream("DataFile.dat", IO.FileMode.Open)
        Try
            Dim formatter As New
Runtime.Serialization.Formatters.Binary.BinaryFormatter

            Return DirectCast(formatter.Deserialize(fs), TestClass)
        Catch e As Runtime.Serialization.SerializationException
            MessageBox.Show("Failed to deserialize. Reason: " &
e.Message)
            Throw
        Finally
            fs.Close()
        End Try
    End Function

Can anybody give me an advice to solve my problem please?
Or does anybody know a simpler\better way to save an object?

Thanks,
Norman

30 Nov 2006 3:49 PM

Steve Long

It might be helpful to know what the error is that you're getting.

S

Show quoteHide quote

"Norman Chong" <normanch***@freenet.de> wrote in message
news:1164890041.094003.23330@l39g2000cwd.googlegroups.com...
> Hiddeldi ho,
>
> I want to save an object so that I can use its content after I restart
> my program. I tried to solve this with serialization because someone
> told me that this is the correct way for this.
> So I wrote the following code to serialize\deserialize the object, but
> now I have the problem that the object has a generic list and when I'm
> trying to deserialize it, I get an error.
>
> <System.Serializable()> Public Class TestClass
>    Implements Runtime.Serialization.ISerializable
> Private lstContent As List(Of Object)
>
>    Public Sub New(ByVal info As Serialization.SerializationInfo, ByVal
> context As Serialization.StreamingContext) Implements
> Serialization.ISerializable.GetObjectData
>        lstContent = CType(info.GetValue("MyList", lstContent.GetType),
> List(Of Object))
>    End Sub
>
>    Public Sub GetObjectData(ByVal info As
> Serialization.SerializationInfo, ByVal context As
> Serialization.StreamingContext) Implements
> Serialization.ISerializable.GetObjectData
>        info.addValue("MyList",lstContent)
>    End Sub
>
>    Public Sub Serialize()
>        Dim fs As New IO.FileStream("DataFile.dat", IO.FileMode.Create)
>        ' Construct a BinaryFormatter and use it to serialize the data
> to the stream.
>        Dim formatter As New
> Runtime.Serialization.Formatters.Binary.BinaryFormatter
>        Try
>            formatter.Serialize(fs, Me)
>        Catch e As Runtime.Serialization.SerializationException
>            MessageBox.Show("Failed to serialize. Reason: " &
> e.Message)
>            Throw
>        Finally
>            fs.Close()
>        End Try
>    End Sub
>
>    Public Shared Function Deserialize() As TestClass
>        Dim fs As New IO.FileStream("DataFile.dat", IO.FileMode.Open)
>        Try
>            Dim formatter As New
> Runtime.Serialization.Formatters.Binary.BinaryFormatter
>
>            Return DirectCast(formatter.Deserialize(fs), TestClass)
>        Catch e As Runtime.Serialization.SerializationException
>            MessageBox.Show("Failed to deserialize. Reason: " &
> e.Message)
>            Throw
>        Finally
>            fs.Close()
>        End Try
>    End Function
>
> Can anybody give me an advice to solve my problem please?
> Or does anybody know a simpler\better way to save an object?
>
> Thanks,
> Norman
>

1 Dec 2006 8:56 AM

Norman Chong

Steve Long wrote:

> It might be helpful to know what the error is that you're getting.

Hi Steve
My deserialized object always had the value 'nothing'. But I already
solved the problem (I just forgot to post that - Sorry!)

Thanks,
Norman