Deserializing a class containing a List<T>: Why is List initially filled with Nulls?
c#, list, serialization
Solution
It is logic. The deserializer deserialized it object by object, then following references. So, first it sets up the List with X spaces... which actually all are NULL.
Then it goes in and deserializes object by object, putting them into the proper references.
All check etc. logic from you should ONLY run AFTER deserialization has completed - per definition you have to always have partial / invalid states while the deserializer runs.
The issue why things are done that late is proabably that your test scenario is a lot easier than the real data, so something makes the serializer "turn the order" on the production side.
Problem
I have a class `Bar` which contains a `List<Foo>`, with both `Foo` and `Bar` implementing ISerializable. When deserializing a `Bar`, the `List<Foo>` is initially filled with (the correct number of) `null`s; then on exiting the `Bar` deserialization ctor, each `Foo`'s deserialization ctor is called, filling the `List<Foo>` with the (correctly deserialized) `Foo`s. Why is this happening? I can't replicate it in a test project: whatever I have tried has resulted in the `Foo` deserialization ctors being called before the `Bar` ctor. This is actually the behaviour I would like, as I need the list to be filled in order to do some initialization for the deserialized `Bar`! Anyone have an idea as to what could be causing the `Foo`s to be deserialized so late? Thanks!