Hi all,

I am coding in VB.NET and here I must use abstract class in my project. When I write to xml file in serialization, there was an error generating the XML document. The following is the code:

Public Class Form1
    Inherits System.Windows.Forms.Form
    Public c4 As New Class4()
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim c1 As New Class1()
        c1.a = "2"
        c1.b = " 3"
        Dim c2 As New Class2()
        c1.cc = c2
        c2.m = "4"
        c4.items.Add(c1)
        c4.save()
    End Sub
 End Class

Public Class Class1
    Public a As String
    Public b As String
    Public cc As Class3
 End Class

Public Class Class2
    Inherits Class3
    Public m As String
End Class


Imports System.Xml.Serialization
Imports System.IO
Public Class Class4
    <XmlIgnore()> Public items As New ArrayList()
    Public Property c1() As Class1()
        Get
            Dim c1array(items.Count - 1) As Class1
            items.CopyTo(c1array)
            Return c1array
        End Get
        Set(ByVal Value As Class1())
             items.Clear()
            If Not Value Is Nothing Then
                Dim c1 As Class1
                For Each c1 In Value
                    items.Add(c1)
                Next
            End If
        End Set
    End Property

    Public Sub save()
        Dim ser As New XmlSerializer(Me.GetType)
        Dim writer As New StreamWriter("c:\file.xml")
'error information appeared in this statement
        ser.Serialize(writer, Me)
        writer.Close()
    End Sub
End Class

Thanks a lot in advance,
Haiying

Hey,

I don't think you can serialize in that way, I think you need the live object and serialize that. So like the function would be in the form, and the form would serialize the class.

Brian

Hi Brian,

I tried to serialize the live object, but it still does not work. The error information is as same as before. I guess the problem is there is an abstract class inside. Then I used SoapFormatter class, the object can be written into xml file, but the format is almost unreadable.

Haiying

Hey,

What is the error message, and could the problem be with <XmlIgnore()>?

Brian

Hey,

The error message is "there was an error generating the XML document".I have add <XmlIgnore()> to some variables which are not useful. If I add <XmlIgnore()> in front of the abstract class variable in class1, the error disappeared.

Haiying