[Mono-devel-list] Different behaviour deserializing ISerializable trees Mono <-> .NET

[Jörg Rosenkranz]

Hi all,

I have run into a problem serializing/deserializing classes which 
implement ISerializable.

I have two classes:
1) A data holding class.
2) A collection class for objects of class 1

Both classes implement ISerializable. The class 1 objects are 
stored in class 2 in a Hashtable internally. I want to restore key 
to object relation in the deserialization constructor of the 
collection class.

My problem is that the collection elements are deserialized *after* the 
collection class. When I access them in the constructor of class 2
they are empty.

You can try the attached sample. It doesn't use Hashtable but shows 
the different behaviour. Using Mono it prints:

========== Serialization ==========
Serializing TestCollection...
0 - Adding member: Value1=member1, Value2=test1 ...
1 - Adding member: Value1=member2, Value2=test2 ...
2 - Adding member: Value1=member3, Value2=test3 ...
TestCollection serialized.
Serializing TestMember: Value1=member3, Value2=test3 ...
TestMember serialized.
Serializing TestMember: Value1=member1, Value2=test1 ...
TestMember serialized.
Serializing TestMember: Value1=member2, Value2=test2 ...
TestMember serialized.
========== Deserialization ==========
Deserializing TestCollection...
0 - New deserialized member: Value1=, Value2= ...
1 - New deserialized member: Value1=, Value2= ...
2 - New deserialized member: Value1=, Value2= ...
Deserialized TestCollection.
Deserializing TestMember...
Deserialized TestMember: Value1=member3, Value2=test3
Deserializing TestMember...
Deserialized TestMember: Value1=member1, Value2=test1
Deserializing TestMember...
Deserialized TestMember: Value1=member2, Value2=test2
========== Result ==========
0: Value1=member1, Value2=test1
1: Value1=member2, Value2=test2
2: Value1=member3, Value2=test3

Running (and compiled too!!) under MS .NET:

========== Serialization ==========
Serializing TestCollection...
0 - Adding member: Value1=member1, Value2=test1 ...
1 - Adding member: Value1=member2, Value2=test2 ...
2 - Adding member: Value1=member3, Value2=test3 ...
TestCollection serialized.
Serializing TestMember: Value1=member1, Value2=test1 ...
TestMember serialized.
Serializing TestMember: Value1=member2, Value2=test2 ...
TestMember serialized.
Serializing TestMember: Value1=member3, Value2=test3 ...
TestMember serialized.
========== Deserialization ==========
Deserializing TestMember...
Deserialized TestMember: Value1=member1, Value2=test1
Deserializing TestMember...
Deserialized TestMember: Value1=member2, Value2=test2
Deserializing TestMember...
Deserialized TestMember: Value1=member3, Value2=test3
Deserializing TestCollection...
0 - New deserialized member: Value1=member1, Value2=test1 ...
1 - New deserialized member: Value1=member2, Value2=test2 ...
2 - New deserialized member: Value1=member3, Value2=test3 ...
Deserialized TestCollection.
========== Result ==========
0: Value1=member1, Value2=test1
1: Value1=member2, Value2=test2
2: Value1=member3, Value2=test3


As you can see the result is the same after deserialization
but not inside the constructor.

Is this a bug or a feature or simply bad usage of serialization? ;-)

And no, I can't serialize the Hashtable directly because then it
would be binary imcompatible between Mono and .NET.

Thanks in advance for any comments,
Jörg
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