Can somebody explain me the internals of Deserialization?

I want to know how deserialization works and is it really needed to have th开发者_如何学运维e assembly on that system where the deserialization is happening.

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If you haven't looked at MSDN yet, do so. It will tell you everything you need to know about the serialization/deserialization process...at least enough to use it. The link I gave you is specifically 'how to deserialize.'

As far as the more technical aspects, the pieces of information that will get serialized will be exactly what is required to fill that structure/class/object.

I'm not really sure what you mean by the 2nd part of your question about the assembly. However, if you are serializing a struct (for instance), then in order to deserialize to another machine, or application, you must have that exact same struct available: name, fields, data types, etc.

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If you're looking for the exact details, you can boot up an instance of Reflector and point it to mscorlib and look into the various classes in the System.Runtime.Serialization namespace. Here's the high-level idea (as I understand it):

The first step is ensuring that the type system that wrote binary stream is the same as the type system that is reading the binary stream. Since so little meta-information is attached to the output, problems can arise if we're not looking at the same type. If we have two classes named A, but the writer thinks an A is class A { int m_a, m_b; } and the reader thinks A is class A { int m_b, m_a; }, we're going to have problems. This problem is much worse if the types are significantly different. Keep this in mind, it will come back later.

Okay, so we're reading and writing the same types. The next step is finding all the members of the object you want to serialize. You could do this through reflection with a call like typeof(T).GetFields(~System.Reflection.BindingFlags.Default), but that will be super-slow (rule of thumb: reflection is slow). Luckily, .NET's internal calls are much faster.

Step 1: Now we get to writing. First: the writer writes the strong-name assembly that the object we're serializing resides in. The reader can then confirm that they actually have this assembly loaded. Next, the object's namespace-qualified type is written, so the reader can read into the proper object. This basically guarantees that the reading type and writing type is the same.

Step 2: Time to actually write the object. A look at the methods of Formatter lets us know that there is some basic functionality for writing ints, floats and all sorts of simple types. In a pre-determined order (the order they are declared, starting from the fields of the base class), each field is written to the output. For fields that are not the simple types, recurse back to step 1 with the object in that field.

To deserialize, you perform these same steps, except replace all the verbs such as 'write' with verbs like 'read.' Order is extremely important.