Object serialization and attributes

Moving from Delphi to Oxygene, I’m learning Oxygene as well as .Net framework.

Currently I’m trying to translate a C# example of object serialization to Oxygene:
https://msdn.microsoft.com/en-us/library/et91as27.aspx

The problem is how to prevent a member - PropertyChangedEventHandler event in this case - from being serialized. Defining [field: NonSerialized] attribute above the definition of the event gives “(E374) comma(,) or close square bracket (]) expected, got colon(:)”.

It works fine if you use “var” instead of “field”:

    [var: NonSerialized]
    event PropertyChanged: System.ComponentModel.PropertyChangedEventHandler;