SerializeTagEventArgs.Context Property

class MyTag
{
    public MyTag(int intValue, string stringValue)
    {
        IntValue = intValue;
        StringValue = stringValue;
}

    public int IntValue;
    public string StringValue;
}

// ...

private void OnSerializeTag(object sender, SerializeTagEventArgs e)
{
    if (e.Tag is MyTag)
    {
        e.Handled = true;
        e.Context.WriteBool(true, "mytag", e.Representation);

        MyTag tag = e.Tag as MyTag;
        e.Context.WriteInt(tag.IntValue, "intValue", e.Representation);
        e.Context.WriteString(tag.StringValue, "stringValue", e.Representation);
    }
}

private void OnDeserializeTag(object sender, SerializeTagEventArgs e)
{
    if (e.Context.ReadBool("mytag", e.Representation, false))
    {
        e.Handled = true;

        int intValue = e.Context.ReadInt("intValue", e.Representation);
        string stringValue = e.Context.ReadString("stringValue", e.Representation);

        e.Tag = new MyTag(intValue, stringValue);
    }
}

Class MyTag

    Public Sub New(ByVal intValue As Integer, ByVal stringValue As String)

        IntValue = intValue;
        StringValue = stringValue;

    End Sub

    Public IntValue As Integer
    Public StringValue As String

End Class

Private Sub OnSerializeTag(ByVal sender As Object, ByVal e As SerializeTagEventArgs)

    If TypeOf e.Tag Is MyTag Then

        e.Handled = True
        e.Context.WriteBool(True, "mytag", e.Representation)

        Dim tag As MyTag = CType(e.Tag, MyTag)
        e.Context.WriteInt(tag.IntValue, "intValue", e.Representation)
        e.Context.WriteString(tag.StringValue, "stringValue", e.Representation)

    End If

End Sub

Private Sub OnDeserializeTag(ByVal sender As Object, ByVal e As SerializeTagEventArgs)

    If e.Context.ReadBool("mytag", e.Representation, False) Then

        e.Handled = True

        Dim intValue As Integer = e.Context.ReadInt("intValue", e.Representation)
        Dim stringValue As String = e.Context.ReadString("stringValue", e.Representation)

        e.Tag = New MyTag(intValue, stringValue)

    End If

End Sub