Serializable Generic Collection

• Download SerializableGenericCollection.zip - 10.8 KB
• Download XmlSerializerDemo.zip - 78.0 KB

Introduction

By default, Generics Collections could not be serialize from xmlserializer. I try to create a generic collection that can serialize in xml format.

        Public Class CollectionBase(Of T)
        Inherits System.Collections.ObjectModel.Collection(Of T)
        Implements System.Xml.Serialization.IXmlSerializable

About This Collection

When we want to made XmlSerializable object we must Implement it from IXmlSerializable. and then we must implement 3 methods (GetSchema,ReadXml,WriteXml). In GetSchema we must return a string that contain XML Schema about this object (We Leave it blank in this version!). ReadXml method will contain statements that deserialize Xml to Objects and finaly in WriteXml we serialize our Collection into Xml.

    
    Public Sub ReadXml(ByVal reader As System.Xml.XmlReader) _
            Implements System.Xml.Serialization.IXmlSerializable.ReadXml
        Dim pc() As PropertyInfo = GetType(T).GetProperties()
        While reader.Read()
            If reader.Name = GetType(T).Name Then
                reader.Read()
                If pc.Length > 0 Then
                    Dim ti As T = GetInstance()
                    For i As Int32 = 0 To pc.Length - 1
                        If pc(i).CanRead And pc(i).CanWrite Then
                            Dim st As SerilalizeType = GetSerilalizeType(pc(i).PropertyType)
                            If st = SerilalizeType.Complex Then
                                Dim o As Object = GetInstance(pc(i).PropertyType)
                                DesrializeObject(reader, o, pc(i).Name)
                                pc(i).SetValue(ti, _
                                               Convert.ChangeType(o, pc(i).PropertyType), _
                                                   Nothing)
                            ElseIf st = SerilalizeType.Guid Then
                                Dim strGuid As String = reader.ReadElementString(pc(i).Name)
                                Dim newId As Guid = New Guid(strGuid)
                                pc(i).SetValue(ti, New Guid(strGuid), Nothing)

                            ElseIf st = SerilalizeType.Array Then
        
                                Dim o As Object = Nothing
                                DesrializeArray(reader, o, pc(i).PropertyType)
                                pc(i).SetValue(ti, _
                                               Convert.ChangeType(o, pc(i).PropertyType), _
                                                   Nothing)


                            ElseIf st = SerilalizeType.ICollection Then
                                Dim o As Object = Nothing
                                DesrializeCollection(reader, o, pc(i).PropertyType)
                                pc(i).SetValue(ti, _
                                       Convert.ChangeType(o, pc(i).PropertyType), _
                                           Nothing)

                            Else
                                pc(i).SetValue(ti, _
                                Convert.ChangeType( _
                                reader.ReadElementString(pc(i).Name), pc(i).PropertyType), _
                                    Nothing)

                            End If

                        End If

                    Next
                    Me.Add(ti)

                End If

            End If

        End While

    End Sub

    Public Sub WriteXml(ByVal writer As System.Xml.XmlWriter) _
            Implements System.Xml.Serialization.IXmlSerializable.WriteXml
        Dim pc() As PropertyInfo = GetType(T).GetProperties()
        Dim ti As T = Nothing
        For i As Int32 = 0 To Me.Items.Count - 1
            ti = Me.Item(i)
            writer.WriteStartElement(GetType(T).Name)
            For j As Int32 = 0 To pc.Length - 1
                If pc(j).CanRead And pc(j).CanWrite Then
                    writer.WriteStartElement(pc(j).Name)
                    Dim st As SerilalizeType = GetSerilalizeType(pc(j).PropertyType)
                    If st = SerilalizeType.Complex Or _
                       st = SerilalizeType.Array Or _
                       st = SerilalizeType.ICollection Then
                        writer.WriteRaw(SerializeObject(pc(j).GetValue(ti, Nothing)))

                    Else
                        writer.WriteString(pc(j).GetValue(ti, Nothing).ToString())

                    End If
                    writer.WriteEndElement()

                End If

            Next
            writer.WriteEndElement()

        Next

    End Sub

        

Using the code

As normaly use of Generic Collections :

  
    Dim MyCol As New DNE.Components.CollectionBase(Of SomeObject)
    

I suggest that inherit from this class. Our collection can now deserialize simple properties like string,integer and Arrays and Obects that inherits from ICollection.

ToDo

Support serialization for Hashtables, Enums and ....

History

Version 0.2 : Support for Array and ICollection, Fixed some bugs. 28/11/2007

Version 0.1 : Initial Release 11/11/2007