Serialization in DotNet

7/31/2019 Serialization in DotNet

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Serialization in DotNetSerialization is the Process of objects getting transformed to stream of bytes to be stored in a

File, Memory or a Database. The Main Purpose of Serialization is to Save the State of the object

in order to recreate it when needed. The reverse of this Process is called as De-Serialization.

Serialization as said before stores the state of the object in Stream of bytes which can be stored

in a File, Database or in Memory.

Using which a developer can easily recreate the same instance of the object with all its

properties whenever required.

Different Serialization Formats

A. Binary Format: Binary formatter is the most efficient way to serialize objects thatwill only be read by .NET framework-based applications. This formatter class is in the

System.Runtime.Serialization.Formatters.Binary

B. Soap Format : This XML Based formatter is easily read by .NET and non-.NETframework based applications .

A) Working sample of Binary Formatter :

1) You need to write the Serializable Class

_

Class SerializeObjects

Dim name AsString

PublicProperty EmpName() AsString

Get

Return name

EndGetSet(ByVal value AsString)

name = value

EndSetEndProperty

EndClass

2) Now The class in which the Serialization will take place

Imports System.IO

Imports System.Runtime.Serialization.Formatters.Binary

Class BinaryExample

SharedSub Main()


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Dim ser AsNew SerializeObjects

ser.EmpName = "Hefin"

Dim binFor AsNew BinaryFormatter()

binFor.Serialize(File.Create("Demo.bin"), ser)

EndSub

End Class

B) Working sample of the SOAP formatter

The Serializable class remains the same only thing that changes is the class where the

serialization will take place.

NOTE : A reference to the Namespace System.Runtime.Serialization.Formatters.Soap needs to

be added.

Imports System.IO

Imports System.Runtime.Serialization.Formatters.Soap

Class SoapExample

SharedSub Main()


ser.EmpName = "Hefin"

Dim soapFor AsNew SoapFormatter()

soapFor.Serialize(File.Create( "Demo.xml"), ser)

EndSub

End Class

De-Serialization :- The reverse of the serialization process is called the De-Serialization .

De-Serialization of the SOAP Serialized Object

Imports System.IO


Class SoapExample

SharedSub Main()


Dim soapFor AsNew SoapFormatter()


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ser = soapFor.Deserialize(File.Open("Demo.xml", FileMode.Open))

Console.WriteLine(ser.EmpName)

EndSub

End Class

De-Serialization of the Binary Serialized Object

Imports System.IO


Class BinaryExample

SharedSub Main()


Dim binFor AsNew BinaryFormatter()

ser = binFor.Deserialize(File.Open("Demo.xml", FileMode.Open))

Console.WriteLine(ser.EmpName)

EndSub

End Class

Serialization

XML Serialization

Object Serialization is a process through which an object's state is transformed into someserial data format, such as XML or binary format, in order to be stored for some later use.In other words, the object is "dehydrated" and put away until we need to use it again.

Some good uses for serialization/deserialization include:

1. Storing user preferences in an object.2. Maintaining security information across pages and applications.3. Modification of XML documents without using the DOM.4. Passing an object from on application to another.5. Passing an object from one domain to another.6. Passing an object through a firewall as an XML string.


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XML Serialization: It is limited that it can serialize only public members.Required Namespace :

Imports System.XmlImports System.Xml.Serialization

Create XSD file from Class

Object instance into XML file

Create one web project and add Person.vb class file.

Imports SystemImports System.XmlImports System.Xml.Serialization

Namespace XMLSerialization'''

''' Summary description for Person.''' _PublicClass Person

Private m_sName AsStringPrivate m_iAge AsIntegerPublicSubNew()EndSub _PublicProperty Name() AsString

GetReturn m_sName

EndGetSet(ByVal value AsString)

m_sName = valueEndSet

EndProperty _PublicProperty Age() AsInteger

GetReturn m_iAge

EndGetSet(ByVal value AsInteger)

m_iAge = valueEndSet

EndPropertyPublicFunction Hello() AsString

Return"Hi! My name is " + Name + " and I am " + Age.ToString() + " years old"EndFunctionPublicFunction GoodBye() AsString

Return"So long"EndFunction

EndClassEndNamespace


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[XMLRoot()] and [XMLElement()] these are the .net attributes and tell the serializer where

the various members of this object will appear in the XML document and what they will benamed. Without these, serialization cannot take place.

Dim objXmlSer AsNew XmlSerializer(GetType(Person))Dim objLucky AsNew Person()

Dim objStrWrt As StreamWriterobjLucky.Name = "Myname"

objLucky.Age = 30

Response.Write(objLucky.Hello())

Response.Write(objLucky.GoodBye())

objStrWrt = New StreamWriter(Server.MapPath("abc.xml"))objXmlSer.Serialize(objStrWrt, objLucky)

objStrWrt.Close()

First of al, we declare and instantiate an XMLSerializer object. The typeof() functiondescribes what type of object it's going to be serializing. Then we assign Name and Age

properties of the Person object. Then we used to see the output of that object by callingHello() and GoodBye() functions. Then we initiates a StreamWriter object and that it will be

writing to a file call abc.xml. We then call the Serialize() method of the XMLSerializer object

and send it our person object to be serialized as well as the StreamWriter object so it willwrite the resulting XML to the file specified. Then we close the StreamWriter.

The Abc.Xml file is look like.


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Dim objDesPerson AsNew Person()Dim objStrRdr As StreamReaderobjStrRdr = New StreamReader(Server.MapPath("abc.xml"))Dim objXmlSer AsNew XmlSerializer(GetType(Person))objDesPerson = DirectCast(objXmlSer.Deserialize(objStrRdr), Person)

Response.Write(objDesPerson.Name)

Response.Write(objDesPerson.Age.ToString())objStrRdr.Close()

Binary Serialization

PublicClass ArticlePublic sTitle AsStringPublic sAuthor AsStringPublic sText AsString

EndClass

Not much to this class, just a few string variables. Lets suppose that we need to write an

instance of this call tout to disk. To do this, we can use binary serialization. This will createa binary file that can be read back in as an instance of Article. To do this, we will need to

implement 2 methods GetObjectData and Overloaded Constructor.

It will requires following namespace:

Imports System.Runtime.SerializationImports System.Runtime.Serialization.Formatters.Binary

First we will make the class with serializable attribute and implements the ISerializable

interface.

[Serializable()]

PublicClass ArticlesImplements ISerializable

EndClass

We have to implements GetObjectData method of ISerializable interface.

PublicSub GetObjectData(ByVal info As SerializationInfo, ByVal context As

StreamingContext)info.AddValue("Title", sTitle)info.AddValue("Author", sAuthor)info.AddValue("Text", sText)

EndSub

This method will allow you to serialize the objects to disk. We could add any code in herethat we wanted to customize the way the data is serialized.

Now we need a method to retrieve the data from a serialized object then we will use aoverloaded constructor for this.


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PublicSubNew(ByVal info As SerializationInfo, ByVal context As StreamingContext)sTitle = Convert.ToString(info.GetValue("Title", GetType(String)))sAuthor = Convert.ToString(info.GetValue("Author", GetType(String)))sText = Convert.ToString(info.GetValue("Text", GetType(String)))

EndSub

The empty constructor is added here so that you can create a new Article object withoutdeserialized one.

Now we have a class that can be serialized and deserialized. For serializing this class wehave to create methods like

Serializing the object

PublicSub serialize(ByVal fileName AsString)Dim s AsNew FileStream(fileName, FileMode.Create, FileAccess.ReadWrite)Dim B AsNew BinaryFormatter()B.Serialize(s, Me)

s.Close()EndSub

Here first we create an instance of FileStream class which, will create file and open it in read

and write mode. Next we create an instance of BinaryForamtter class. This class have

Seralize method which take parameters FileStream and Instance which you want toserialize.

DeSerializing the object

PublicFunction deSerialize(ByVal fileName AsString) As ArticlesDim Fs AsNew FileStream(fileName, FileMode.Open, FileAccess.Read)Dim F AsNew BinaryFormatter()Dim s1 As Articles = DirectCast(F.Deserialize(Fs), Articles)Fs.Close()Return s1

EndFunction

Here again create an instance of BinaryFormatter. The method Deserialize() will take

parameter of FileStream object which point to the binary file which you want to deserialize.

You have to do explicit casting of Article type during Deserializing.

Create One Project For Serializing

Create one Articles.vb class file

Imports SystemImports System.IOImports System.Runtime.SerializationImports System.Runtime.Serialization.Formatters.BinaryNamespace BinarySerialization

_PublicClass Articles

Implements ISerializable


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Public sTitle AsStringPublic sAuthor AsStringPublic sText AsString

PublicSubNew()EndSub

PublicSubNew(ByVal info As SerializationInfo, ByVal context As StreamingContext)sTitle = Convert.ToString(info.GetValue("Title", GetType(String)))sAuthor = Convert.ToString(info.GetValue("Author", GetType(String)))sText = Convert.ToString(info.GetValue("Text", GetType(String)))

EndSubPublicSub serialize(ByVal fileName AsString)

Dim s As FileStreams = New FileStream(fileName, FileMode.Create, FileAccess.ReadWrite)Dim B AsNew BinaryFormatter()B.Serialize(s, Me)s.Close()

EndSubPublicFunction deSerialize(ByVal fileName AsString) As Articles

Dim Fs AsNew FileStream(fileName, FileMode.Open, FileAccess.Read)Dim F AsNew BinaryFormatter()Dim s1 As Articles = DirectCast(F.Deserialize(Fs), Articles)Fs.Close()Return s1

EndFunction#Region"ISerializable Members"

PublicSub GetObjectData(ByVal info As SerializationInfo, ByVal context As

StreamingContext)info.AddValue("Title", sTitle)info.AddValue("Author", sAuthor)

info.AddValue("Text", sText)EndSub#EndRegion

EndClassEndNamespace

Create one webForm1.aspx page for testing the binary serialization.

'Binary Serialization of the objectDim c1 AsNew Articles()c1.sTitle = "My Title"c1.sAuthor = "Author Name"

c1.sText = "This is my Text"c1.serialize("C:\123.txt")

'deserialization of the object

Dim c2 As Articles = c1.deSerialize("C:\123.txt")Response.Write(c2.sTitle)Response.Write(c2.sAuthor)

Response.Write(c2.sText)


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13.24.1.Class binary Serialization

Imports System

Imports System.IO

Imports System.Runtime.Serialization



Public Class Tester

Public Shared Sub Main

DimmyClsSerializableAs New ClsSerializable()

SerializeBinary(myClsSerializable)

Console.WriteLine(FileContent(False))

DimmyFileStreamAs FileStream

myFileStream = New FileStream("test.dat", FileMode.Open, FileAccess.R

ead)

DimmyFormatterAs New BinaryFormatter()

myClsSerializable = CType(myFormatter.Deserialize(myFileStream), ClsS

erializable)

Console.WriteLine(myClsSerializable.intNumber.ToString)

Console.WriteLine(myClsSerializable.lngNumber.ToString)

Console.WriteLine(myClsSerializable.strDemo)

End Sub

Private SharedFunction FileContent(ByVal blnBinaryAs Boolean)As String

DimstrContentAs String

DimmyStreamReaderAs StreamReader

DimmyFileStreamAs FileStream

DimiAs Integer

Try

myFileStream = New FileStream("test.dat", FileMode.Open, FileAcce

ss.Read)

If blnBinary = True Then

For i = 1 To myFileStream.Length

strContent += myFileStream.ReadByte.ToString +" "

Next

Else

myStreamReader = New StreamReader(myFileStream)

strContent = myStreamReader.ReadToEnd

End If

myFileStream.Flush()

myFileStream.Close()

Return strContent

Catch exAs IOException

Console.WriteLine(ex.Message)

End Try


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EndFunction

Private Shared Sub SerializeBinary(ByVal myClsSerializableAs ClsSerializ

able)

DimmyFileStreamAs FileStream = New FileStream("test.dat", FileMode.

Create, FileAccess.Write)

DimmyBFormatterAs BinaryFormatter = New BinaryFormatter()

myBFormatter.Serialize(myFileStream, myClsSerializable)

myFileStream.Flush()

myFileStream.Close()

End Sub

End Class

Public Class ClsSerializable

Public intNumberAs Integer = 254

Public strDemoAs String = "This is a poublic test string"

Private strpDemoAs String = "This is a private test string"

Public lngNumberAs Long = 123456

End Class

Binary Serialization Example

[TOC]

Imports System

Imports System.IO


ImportsCenterSpace.NMath.Core

Namespace CenterSpace.NMath.Core.Examples.VisualBasic

' A .NET example in VB.NET showing how to serialize and deserialize an

NMath object

' in binary format.

Module SoapSerializationExample

Private filename As String = "data.dat"

Sub Main()

Console.WriteLine()

' Delete old file, if it exists

If (File.Exists(filename)) Then

Console.WriteLine("Deleting old file")

File.Delete(filename)

End If
http://www.centerspace.net/examples/nmath/index.phphttp://www.centerspace.net/examples/nmath/index.phphttp://www.centerspace.net/doc/NMathSuite/ref/html/N_CenterSpace_NMath_Core.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/N_CenterSpace_NMath_Core.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/N_CenterSpace_NMath_Core.htmhttp://www.centerspace.net/examples/nmath/index.php


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' Create vector

Dim u As NewDoubleVector("[ 5.6 4.2 5.3 -0.004 434 ]")

' Persist to file

Dim stream As FileStream = File.Create(filename)

Dim formatter As New BinaryFormatter()

Console.WriteLine("Serializing vector")

formatter.Serialize(stream, u)

stream.Close()

' Restore from file

stream = File.OpenRead(filename)

Console.WriteLine("Deserializing vector")

Dim v AsDoubleVector = formatter.Deserialize(stream)

stream.Close()

Console.WriteLine()

Console.WriteLine("Press Enter Key")

Console.Read()

End Sub

End Module

End Namespace
http://www.centerspace.net/doc/NMathSuite/ref/html/T_CenterSpace_NMath_Core_DoubleVector.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/T_CenterSpace_NMath_Core_DoubleVector.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/T_CenterSpace_NMath_Core_DoubleVector.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/T_CenterSpace_NMath_Core_DoubleVector.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/T_CenterSpace_NMath_Core_DoubleVector.htmhttp://www.centerspace.net/doc/NMathSuite/ref/html/T_CenterSpace_NMath_Core_DoubleVector.htm

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Serialization in DotNet