Serialize Object instances when specific property has value

Question

Hallo,

I want to Serialize list of Objects when it is specific property has value. I have following code it woks partially ..if you see the screenshot i have one object instance serialized but i want to eliminate remaining empty tag elements (<cWBS/>) from the xml file . How can i do that?

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load  
  
	Dim WBSList As New WBS  
  
	With WBSList  
            .Add(New cWBS With {.L4 = 1, .L5 = 1, .Description = "Item1"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 2, .Description = "Item2"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 3, .Description = "Item3"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 4, .Description = "Item4"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 5, .Description = "Item5"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 6, .Description = "Item6"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 7, .Description = "Item7"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 8, .Description = "Item8"})  
            .Add(New cWBS With {.L4 = 1, .L5 = 9, .Description = "Item9"})  
            .Add(New cWBS With {.Marker = "H0", .L4 = 1, .L5 = 0, .Description = "Item10"})  
	End with  
  
End Sub   
  
  
   Public Sub SerializeObj(obj As Object, ByVal path As String)  
  
        Dim ws As New XmlWriterSettings With {.NewLineHandling = NewLineHandling.Entitize}  
        Dim serializer As New XmlSerializer(obj.GetType, New XmlRootAttribute("Test"))  
  
        Using xmlWriter As XmlWriter = XmlWriter.Create(path, ws)  
            serializer.Serialize(xmlWriter, obj)  
        End Using  
  
    End Sub  
  
    Public Function deSerializeObj(obj As Object, ByVal path As String) As Object  
  
        Try  
  
            Dim fs As FileStream = New FileStream(path, FileMode.Open)  
            Dim serializer As New XmlSerializer(obj.GetType, New XmlRootAttribute("Test"))  
            obj = CType(serializer.Deserialize(fs), Object)  
            fs.Close()  
            Return obj  
  
        Catch ex As Exception  
            MessageBox.Show ("Can Not Read File!")  
        End Try  
  
    End Function  
  
  
Public Class cWBS  
  
    <XmlIgnore()> Public Property ID As Integer?  
    <XmlIgnore()> Public Property Marker As String  
    <XmlIgnore()> Public Property L4 As Integer?     
    <XmlIgnore()> Public Property L5 As Integer?     
    <XmlIgnore()> Public Property L6 As Integer?     
    <XmlIgnore()> Public Property L7 As Integer?    
    <XmlIgnore()> Public Property L8 As Integer?  
  
    <XmlIgnore()>  
    Public Property Description As String  '//   
    Public Property Quantity As Integer?  
  
    <XmlIgnore()>  
    Public Property Cost As Integer?  
    Public Property Remarks As String  
  
    Public Function ShouldSerializeQuantity() As Boolean  
        Return Not Quantity Is Nothing)  
    End Function  
  
End Class  
Public Class WBS  
    Inherits System.ComponentModel.BindingList(Of cWBS)  
End Class  

Answer 1

Hallo @Viorel

No . It has to be de-serialized again. Any alternate method? by keeping ID as primary key and de-serialize it according to ID?

Answer 2

If empty <cWBS/> elements are removed, then the deserialised list will contain less elements than original. Is this the intended behaviour?

To extract the objects to be serialised, consider something like this:

Dim filtered = myList.Where(Function(d) d.Quantity IsNot Nothing)

Then serialise it.