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SerializationInfo.SetType Method

Sets the Type of the object to serialize.

Namespace:  System.Runtime.Serialization
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Sub SetType ( _
	type As Type _
)

Parameters

type
Type: System.Type

The Type of the object to serialize.

ExceptionCondition
ArgumentNullException

The type parameter is Nothing.

The Formatter is responsible for setting the Type of the SerializationInfo instance before passing it to GetObjectData. However, users who want to send proxies for their objects will need to change the type represented by this SerializationInfo instance. Using the SetType method is equivalent to setting both the FullTypeName and the AssemblyName.

Imports System
Imports System.Web
Imports System.IO
Imports System.Collections
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization
Imports System.Security.Permissions


' There should be only one instance of this type per AppDomain.
<Serializable()> _
<PermissionSet(SecurityAction.Demand, Name:="FullTrust")> _
Public NotInheritable Class Singleton
   Implements ISerializable

   ' This is the one instance of this type. 
   Private Shared ReadOnly theOneObject As New Singleton

   ' Here are the instance fields. 
   Private someString As String
   private someNumber As Int32

   ' Private constructor allowing this type to construct the Singleton. 
   Private Sub New()
      ' Do whatever is necessary to initialize the Singleton.
      someString = "This is a string field"
      someNumber = 123
   End Sub 

   ' A method returning a reference to the Singleton. 
   Public Shared Function GetSingleton() As Singleton
      Return theOneObject
   End Function 

   ' A method called when serializing a Singleton.
   <SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags:=SecurityPermissionFlag.SerializationFormatter)> _
   Private Sub GetObjectData(ByVal info As SerializationInfo, _
      ByVal context As StreamingContext) _
      Implements ISerializable.GetObjectData

      ' Instead of serializing this object, we will   
      ' serialize a SingletonSerializationHelp instead.
      info.SetType(GetType(SingletonSerializationHelper))
      ' No other values need to be added. 
   End Sub 

   ' Note: ISerializable's special constructor is not necessary  
   ' because it is never called. 
End Class


<Serializable()> _
<PermissionSet(SecurityAction.Demand, Name:="FullTrust")> _
Friend NotInheritable Class SingletonSerializationHelper
   Implements IObjectReference
   ' This object has no fields (although it could). 

   ' GetRealObject is called after this object is deserialized.
   <SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags:=SecurityPermissionFlag.SerializationFormatter)> _
   Public Function GetRealObject(ByVal context As StreamingContext) As Object Implements IObjectReference.GetRealObject
      ' When deserialiing this object, return a reference to  
      ' the Singleton object instead. 
      Return Singleton.GetSingleton()
   End Function 
End Class 


Class App
   <STAThread()> Shared Sub Main()
      Dim fs As New FileStream("DataFile.dat", FileMode.Create)

      Try 
         ' Construct a BinaryFormatter and use it  
         ' to serialize the data to the stream. 
         Dim formatter As New BinaryFormatter

         ' Create an array with multiple elements refering to  
         ' the one Singleton object. 
         Dim a1() As Singleton = {Singleton.GetSingleton(), Singleton.GetSingleton()}

         ' This displays "True".
         Console.WriteLine("Do both array elements refer to the same object? " & _
            Object.ReferenceEquals(a1(0), a1(1)))

         ' Serialize the array elements.
         formatter.Serialize(fs, a1)

         ' Deserialize the array elements.
         fs.Position = 0
         Dim a2() As Singleton = DirectCast(formatter.Deserialize(fs), Singleton())

         ' This displays "True".
         Console.WriteLine("Do both array elements refer to the same object? " & _
            Object.ReferenceEquals(a2(0), a2(1)))

         ' This displays "True".
         Console.WriteLine("Do all array elements refer to the same object? " & _
            Object.ReferenceEquals(a1(0), a2(0)))
      Catch e As SerializationException
         Console.WriteLine("Failed to serialize. Reason: " & e.Message)
         Throw 
      Finally
         fs.Close()
      End Try 
   End Sub 
End Class

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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