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SerializationInfo.SetType Method

Sets the Type of the object to serialize.

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

public void SetType(
	Type type
)

Parameters

type
Type: System.Type
The Type of the object to serialize.

ExceptionCondition
ArgumentNullException

The type parameter is null.

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.


using System;
using System.Web;
using System.IO;
using System.Collections;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization;
using System.Security.Permissions;


// There should be only one instance of this type per AppDomain.
[Serializable]
[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
[AspNetHostingPermission(SecurityAction.LinkDemand, 
    Level=AspNetHostingPermissionLevel.Minimal)]
public sealed class Singleton : ISerializable 
{
    // This is the one instance of this type.
    private static readonly Singleton theOneObject = new Singleton();

    // Here are the instance fields.
    private string someString_value;
    private Int32 someNumber_value;

   public string SomeString
   {
       get{return someString_value;}
       set{someString_value = value;}
   }

   public Int32 SomeNumber
   {
       get{return someNumber_value;}
       set{someNumber_value = value;}
   }

    // Private constructor allowing this type to construct the Singleton.
    private Singleton() 
    { 
        // Do whatever is necessary to initialize the Singleton.
        someString_value = "This is a string field";
        someNumber_value = 123;
    }

    // A method returning a reference to the Singleton.
    public static Singleton GetSingleton() 
    { 
        return theOneObject; 
    }

    // A method called when serializing a Singleton.
   [SecurityPermissionAttribute(SecurityAction.LinkDemand, 
   Flags=SecurityPermissionFlag.SerializationFormatter)]
    void ISerializable.GetObjectData(
        SerializationInfo info, StreamingContext context) 
    {
        // Instead of serializing this object, 
        // serialize a SingletonSerializationHelp instead.
        info.SetType(typeof(SingletonSerializationHelper));
        // No other values need to be added.
    }

    // Note: ISerializable's special constructor is not necessary 
    // because it is never called.
}


[Serializable]
[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
[SecurityPermissionAttribute(SecurityAction.LinkDemand, 
    Flags=SecurityPermissionFlag.SerializationFormatter)]
[AspNetHostingPermission(SecurityAction.LinkDemand, 
   Level=AspNetHostingPermissionLevel.Minimal)]
internal sealed class SingletonSerializationHelper : IObjectReference 
{
    // This object has no fields (although it could).

    // GetRealObject is called after this object is deserialized.
    public Object GetRealObject(StreamingContext context) 
    {
        // When deserialiing this object, return a reference to 
        // the Singleton object instead.
        return Singleton.GetSingleton();
    }
}


class App 
{
    [STAThread]
    static void Main() 
    {
        FileStream fs = new FileStream("DataFile.dat", FileMode.Create);

        try 
        {
            // Construct a BinaryFormatter and use it 
            // to serialize the data to the stream.
            BinaryFormatter formatter = new BinaryFormatter();

            // Create an array with multiple elements refering to 
            // the one Singleton object.
            Singleton[] a1 = { Singleton.GetSingleton(), Singleton.GetSingleton() };

            // This displays "True".
            Console.WriteLine(
                "Do both array elements refer to the same object? " + 
                (a1[0] == a1[1]));     

            // Serialize the array elements.
            formatter.Serialize(fs, a1);

            // Deserialize the array elements.
            fs.Position = 0;
            Singleton[] a2 = (Singleton[]) formatter.Deserialize(fs);

            // This displays "True".
            Console.WriteLine("Do both array elements refer to the same object? " 
                + (a2[0] == a2[1])); 

            // This displays "True".
            Console.WriteLine("Do all array elements refer to the same object? " 
                + (a1[0] == a2[0]));
        }   
        catch (SerializationException e) 
        {
            Console.WriteLine("Failed to serialize. Reason: " + e.Message);
            throw;
        }
        finally 
        {
            fs.Close();
        }
    }
}


.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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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