Was this page helpful?
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All

MarshalByRefObject Class


Enables access to objects across application domain boundaries in applications that support remoting.

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


public abstract class MarshalByRefObject


Initializes a new instance of the MarshalByRefObject class.


Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Retrieves the current lifetime service object that controls the lifetime policy for this instance.


Gets the Type of the current instance.(Inherited from Object.)


Obtains a lifetime service object to control the lifetime policy for this instance.


Creates a shallow copy of the current Object.(Inherited from Object.)


Creates a shallow copy of the current MarshalByRefObject object.


Returns a string that represents the current object.(Inherited from Object.)

An application domain is a partition in an operating system process where one or more applications reside. Objects in the same application domain communicate directly. Objects in different application domains communicate either by transporting copies of objects across application domain boundaries, or by using a proxy to exchange messages.

MarshalByRefObject is the base class for objects that communicate across application domain boundaries by exchanging messages using a proxy. Objects that do not inherit from MarshalByRefObject are implicitly marshal by value. When a remote application references a marshal by value object, a copy of the object is passed across application domain boundaries.

MarshalByRefObject objects are accessed directly within the boundaries of the local application domain. The first time an application in a remote application domain accesses a MarshalByRefObject, a proxy is passed to the remote application. Subsequent calls on the proxy are marshaled back to the object residing in the local application domain.

Types must inherit from MarshalByRefObject when the type is used across application domain boundaries, and the state of the object must not be copied because the members of the object are not usable outside the application domain where they were created.

This section contains two code examples. The first code example shows how to create an instance of a class in another application domain. The second code example shows a simple class that can be used for remoting.

Example 1

The following code example shows the simplest way to execute code in another application domain. The example defines a class named Worker that inherits MarshalByRefObject, with a method that displays the name of the application domain in which it is executing. The example creates instances of Worker in the default application domain and in a new application domain.


The assembly that contains Worker must be loaded into both application domains, but it could load other assemblies that would exist only in the new application domain.

using System;
using System.Reflection;

public class Worker : MarshalByRefObject
    public void PrintDomain() 
        Console.WriteLine("Object is executing in AppDomain \"{0}\"",

class Example
    public static void Main()
        // Create an ordinary instance in the current AppDomain
        Worker localWorker = new Worker();

        // Create a new application domain, create an instance
        // of Worker in the application domain, and execute code
        // there.
        AppDomain ad = AppDomain.CreateDomain("New domain");
        Worker remoteWorker = (Worker) ad.CreateInstanceAndUnwrap(

/* This code produces output similar to the following:

Object is executing in AppDomain "source.exe"
Object is executing in AppDomain "New domain"

Example 2

The following example demonstrates a class derived from MarshalByRefObject that is used later in remoting.

using System;
using System.Runtime.Remoting;
using System.Security.Permissions;

public class SetObjectUriForMarshalTest  {

    class TestClass : MarshalByRefObject {

    [SecurityPermission(SecurityAction.Demand, Flags=SecurityPermissionFlag.RemotingConfiguration)] 
    public static void Main()  {

        TestClass obj = new TestClass();    

        RemotingServices.SetObjectUriForMarshal(obj, "testUri");


.NET Framework
Available since 1.1

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

Return to top
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
© 2015 Microsoft