c# - Do closures break serialization -

today faced serializationexception refered anonymous inner class +<>c__displayclass10 stating not serializable, when iis tried store session in asp.net state service:

type 'xyz.generalunderstandingtests+aserializabletype+<>c__displayclass10' in assembly 'xyz, version=1.2.5429.24450, culture=neutral, publickeytoken=null' not marked serializable.

i looked lambdas in code , found quite few, of them not new , did never have issues in serialization. noticed had built in new lambda expression "happened" build closure.

searching stackoverflow closure serialization found q&as reveal closures cannot serialized in other languages such php *) did not manage find such statement c#. have been able build simple example seems confirm closures not serializable whereas "normal" functions are

[testfixture] public class generalunderstandingtests {     [serializable]     private class aserializabletype     {         private readonly func<int> thisisaclosure;         private readonly func<int> thisisnotaclosure;          public aserializabletype()         {             const int someconst = 12345;             thisisnotaclosure = () => someconst; // succeeds serialize              var somevariable = 12345;             thisisaclosure = () => somevariable; // fails serialize         }     }      [test]     public void aserializabletype_canbeserialized()     {         var sessionstateitemcollection = new              system.web.sessionstate.sessionstateitemcollection();         sessionstateitemcollection["sut"] = new aserializabletype();         sessionstateitemcollection.serialize(new binarywriter(new memorystream()));     } } 

this test fails goes green line thisisaclosure = ... commented out. line thisisnotaclosure = ... not cause issues someconst not variable constant, is, not build closure inlined compiler.

can confirm have concluded correct?

=> there way circumvent issue?

=> depends on internals of compiler used? since compiler turns lambda/closure expression anonymous inner class.

*) links:

• exception: serialization of 'closure' not allowed
• closures can't serialized, how callbacks via ajax php?
• serialization of 'closure' not allowed php pthreads
• how serialize object has closures inside properties?