Serialization Note 1

灰太狼 2021-11-09 09:04 265阅读 0赞

[Serialization Note 1][]

**Serialization**

**1.       What is Serialization?**

A mechanism to store the state of an object in order to perform operations on the serialized state,

**Deserialization** is the reverse process of serialization in which the object is reconstructed back from the serialized state

During the process of Serialization, the objects are **marshaled by value.**

During Deserialization process, the **formatter reads the stream and constructs the object**.

**2.       Serialization at a high level**

[![7467accb848eb703bf09e6f7.jpg][]][7467accb848eb703bf09e6f7.jpg 1]

**3.       Types of Serialization**

**[![a0e2aff0b5fceadf7831aaf1.jpg][]][a0e2aff0b5fceadf7831aaf1.jpg 1]**

**Shallow Serialization：**

The **XML serialization** technique can convert only the public properties and fields into XML format.

**Deep Serialization：**This inability is overcome by Binary and SOAP serialization techniques in which the state of the entire object is serialized into a stream of bytes. If the object contains references, even those are serialized.

**4.       Formatter**

• Serialization and Deserialization are performed by an object that implements the *IFormatter* interface.

• The .NET framework provides two implementations of this interface

\_ BinaryFormatter

\_ SoapFormatter

The IFormatter interface provides two methods, ***Serialize*** and ***Deserialize***.

• The *Serialize* method takes the object graph and writes its state including the type identity to the stream.

• The *Deserialize* method reads the stream and reconstructs the object graph from the stream.

• In addition to the name-value pairs for each of the object fields, **formatters also intelligently** write the name of the type/class and the assembly in which it is defined, to the stream.

**• By default**, both *BinaryFormatter* and *SoapFormatter* write out the full name of the assembly including its filename, version, culture and public key token.

**5.       Stream**

• Stream is an abstract class located in the **System.IO** namespace.

• Stream essentially defines a pattern for storing and retrieving data.

• .NET framework provides the following stream classes,

\_ to store the data in memory (System.IO.MemoryStream)

\_ to store the data in a file (System.IO.FileStream)

\_ to send data across the network (System.Net.Sockets.NetworkStream)

**6.       Core Namespaces for Serialization**

• The .NET framework provides built-in mechanism to serialize and deserialize objects.

• This functionality can be found in the following namespaces,

\_ System.Runtime.Serialization

\_ System.Xml.Serialization

Note: If BinaryFormatter is used for serializing, then deserialization can be performed only using BinaryFormatter. SoapFormatter cannot be used to deserialize an object serialized using BinaryFormatter.The same applies for SoapFormatter.

**7.       1. Serialization using formatters**

***//Namespace***

*System*

*System.IO (for streams)*

*System.Runtime.Serialization*

*System.Runtime.Serialization.Formatters*

*System.Runtime.Serialization.Formatters.Binary*

***//Code***

*// Create a stream; Can be FileStream etc.*

*MemoryStream strm = new MemoryStream();*

*// Create a serialization formatter; can be any formatter*

*BinaryFormatter fmtr = new BinaryFormatter();*

*// Serial object graph into the stream*

*fmtr.Serialize(strm, objectGraph);*

**De-serialization**

*// Create the serialization formatter*

*BinaryFormatter defmtr = new BinaryFormatter();*

*// Get the object graph back*

*Object obj = defmtr.Deserialize(strm);*

**7.       2. Serialization using XmlSerializer**

***//Namespace***

*System*

*System.IO (for streams)*

*System.Runtime.Serialization*

*System.Xml.Serialization*

***//Code***

*// Create a stream; could have been FileStream etc.*

*MemoryStream strm = new MemoryStream();*

*// Create an instance of XmlSerializer*

*XmlSerializer xs = new XmlSerializer(typeof(class));*

• *// Serial object graph into the stream*

*xs.Serialize(strm, objectGraph);*

**De-serialization using XmlSerializer**

*// Create the XmlSerializer instance*

*XmlSerializer xs = new XmlSerializer(typeof(class));*

*// Get the object graph back*

*Object obj = xs .Deserialize(strm);*

**8.       How the framework locates classes**

• Serialization adds

v      Typename

v      Assembly identity (full name)

• Deserialization

\_ Recovers the Assembly Identity

\_ Loads it, if not already loaded; uses Assembly.Load method.

(Looks in GAC first and then in the local directory)

\_ If class is found in assembly, deserialization proceeds

\_ Else SerializationException is thrown

**9.             Points to remember**

• Mark the class with **Serializable Attribute**

• If base class is not Serializable, derived class cannot be serialized (by design).

• **Multiple object graphs can be serialized into the same stream**.

• Deserialization is FIFO order.

• XmlSerialization is shallow.

• **Serialization performed using BinaryFormatter or SoapFormatter is deep**.

• When a class is marked with Serializable attribute, it will always be marshalled by value

**10.         Selective Serialization**

Selective serialization using **NonSerializable** attribute

• Caveats with NonSeriazable attribute

• Deserialization Callback for initializing fields that were prevented from being serialized using NonSerializable attribute

A class may contain fields that should not be serialized . We can prevent member variables from being serialized by NonSerialized attribute.

• After deserialization, fields that were marked with NonSerialized Attribute will be set to default values.

• Alternatively, Deserialization Callback can be used to initialize those fields automatically.

• NonSerialized Attribute works only with Formatters.

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posted on 2008-11-14 17:59 [Alan Gan][] 阅读( ...) 评论( ...) [编辑][Link 3] 收藏

转载于:https://www.cnblogs.com/AlanGan/archive/2008/11/14/1905783.html

[Serialization Note 1]: https://www.cnblogs.com/AlanGan/archive/2008/11/14/1905783.html
[7467accb848eb703bf09e6f7.jpg]: /images/20211109/ffc279969cb84d0baa76a94a40a7e4d4.png
[7467accb848eb703bf09e6f7.jpg 1]: http://hiphotos.baidu.com/agangsx/pic/item/7467accb848eb703bf09e6f7.jpg
[a0e2aff0b5fceadf7831aaf1.jpg]: /images/20211109/2de6211416964779b5764ae689db71a4.png
[a0e2aff0b5fceadf7831aaf1.jpg 1]: http://hiphotos.baidu.com/agangsx/pic/item/a0e2aff0b5fceadf7831aaf1.jpg
[Link 1]: http://hi.baidu.com/agangsx/blog/item/11bc44136497e8876438dbfb.html
[.net summary]: http://hi.baidu.com/agangsx/blog/category/.net%20summary
[Link 2]: http://hi.baidu.com/agangsx/blog/item/11bc44136497e8876438dbfb.html#comment
[Alan Gan]: https://www.cnblogs.com/AlanGan/
[Link 3]: https://i.cnblogs.com/EditPosts.aspx?postid=1905783