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SurrogateSelector Class

Assists formatters in selection of the serialization surrogate to delegate the serialization or deserialization process to.

System.Object
  System.Runtime.Serialization.SurrogateSelector
    System.Workflow.ComponentModel.Serialization.ActivitySurrogateSelector

Namespace:  System.Runtime.Serialization
Assembly:  mscorlib (in mscorlib.dll)
[ComVisibleAttribute(true)]
public class SurrogateSelector : ISurrogateSelector

The SurrogateSelector type exposes the following members.

  Name Description
Public method SurrogateSelector Initializes a new instance of the SurrogateSelector class.
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  Name Description
Public method AddSurrogate Adds a surrogate to the list of checked surrogates.
Public method ChainSelector Adds the specified ISurrogateSelector that can handle a particular object type to the list of surrogates.
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetNextSelector Returns the next selector on the chain of selectors.
Public method GetSurrogate Returns the surrogate for a particular type.
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method RemoveSurrogate Removes the surrogate associated with a given type.
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
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A serialization surrogate gives the users an object that can handle the serialization requirements of a different object and can transform the serialized data if necessary.

The following code example shows how to make a serialization surrogate class that knows how to properly serialize or deserialize a class that is not itself serializable. In addition, this example also shows how to recover from a SerializationException.


using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters;
using System.Runtime.Serialization.Formatters.Binary;


// This class is not serializable.
class Employee 
    {
    public String name, address;

    public Employee(String name, String address) 
    {
        this.name = name;
        this.address = address;
    }
}

// This class can manually serialize an Employee object.
sealed class EmployeeSerializationSurrogate : ISerializationSurrogate 
{

    // Serialize the Employee object to save the object�s name and address fields.
    public void GetObjectData(Object obj, 
        SerializationInfo info, StreamingContext context) 
    {

        Employee emp = (Employee) obj;
        info.AddValue("name", emp.name);
        info.AddValue("address", emp.address);
    }

    // Deserialize the Employee object to set the object�s name and address fields.
    public Object SetObjectData(Object obj,
        SerializationInfo info, StreamingContext context,
        ISurrogateSelector selector) 
    {

        Employee emp = (Employee) obj;
        emp.name = info.GetString("name");
        emp.address = info.GetString("address");
        return null;
    }
}

public sealed class App 
{
    static void Main() 
    {
        // This sample uses the BinaryFormatter.
        IFormatter formatter = new BinaryFormatter();

        // Create a MemoryStream that the object will be serialized into and deserialized from.
        using (Stream stream = new MemoryStream()) 
        {
            // Create a SurrogateSelector.
            SurrogateSelector ss = new SurrogateSelector();

            // Tell the SurrogateSelector that Employee objects are serialized and deserialized 
            // using the EmployeeSerializationSurrogate object.
            ss.AddSurrogate(typeof(Employee),
            new StreamingContext(StreamingContextStates.All),
            new EmployeeSerializationSurrogate());

            // Associate the SurrogateSelector with the BinaryFormatter.
            formatter.SurrogateSelector = ss;

            try 
            {
                // Serialize an Employee object into the memory stream.
                formatter.Serialize(stream, new Employee("Jeff", "1 Microsoft Way"));
            }
            catch (SerializationException e) 
            {
                Console.WriteLine("Serialization failed: {0}", e.Message);
                throw;
            }

            // Rewind the MemoryStream.
            stream.Position = 0;

            try 
            {
                // Deserialize the Employee object from the memory stream.
                Employee emp = (Employee) formatter.Deserialize(stream);

                // Verify that it all worked.
                Console.WriteLine("Name = {0}, Address = {1}", emp.name, emp.address);
            }
            catch (SerializationException e) 
            {
                Console.WriteLine("Deserialization failed: {0}", e.Message);
                throw;
            }
        }
    }
}

// This code produces the following output.
//
// Name = Jeff, Address = 1 Microsoft Way


.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.
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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