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IObjectReference Interface

Indicates that the current interface implementer is a reference to another object.

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

[ComVisibleAttribute(true)]
public interface IObjectReference

The IObjectReference type exposes the following members.

  NameDescription
Public methodGetRealObjectReturns the real object that should be deserialized, rather than the object that the serialized stream specifies.
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Notes to Implementers

Implement this interface on objects that are references to a different object, which cannot be resolved until the current object is completely restored. During the fixup stage, any object implementing IObjectReference is queried for its real object and that object is inserted into the graph. Fixup refers to the process of finalizing references not already completed during the object deserialization process.

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: 4.6, 4.5, 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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