Type: System.Runtime.Remoting.ObjRef

System.Runtime.Remoting.ObjRef Class

Assembly: Mscorlib.dll
Namespace: System.Runtime.Remoting

Summary: Stores all relevant information required to generate a proxy in order to communicate with a remote object.

C# Syntax:

[Serializable]
public class ObjRef : IObjectReference, ISerializable

Remarks

An ObjRef is a serializable representation of an object that extends MarshalByRefObject (MBR). An ObjRef is used to transfer an object reference across an AppDomain boundary. Creating an ObjRef for an object is known as marshaling. You can create an ObjRef (marshal a MarshalByRefObject) either explicitly, by registering the MBR object with the remoting infrastructure (see RemotingConfiguration and RemotingServices.Marshal), or implicitly, by passing an MBR object as a parameter when calling a remote object. Remoting uses ObjRef objects to store and transmit all the relevant information about the MarshalByRefObject being remoted.

The ObjRef contains information that describes the Type and class of the object being marshaled, its exact location, and communication-related information on how to reach the remoting subdivision where the object is located.

After a class implementing MarshalByRefObject is marshaled, the ObjRef that represents it is transferred through a channel into another AppDomain, possibly in another process or computer. When the ObjRef is deserialized (see the conceptual topic at MSDN: serialization) in the target AppDomain, it is parsed to create a transparent proxy for the remote MBR object. This operation is known as unmarshaling.

A transparent proxy is an object that provides the illusion that the actual object resides in the client's space. It achieves this by forwarding calls made on it to the real object using the remoting infrastructure. The transparent proxy is itself housed by an instance of a managed run-time class of type RealProxy. The RealProxy implements a part of the functionality needed to forward the operations from the transparent proxy.

A proxy object can be used without regard to any remoting subdivisions within an AppDomain. Applications need not distinguish between proxy references and object references. However, service providers dealing with issues such as activation, lifetime management, and transactions need to make such distinctions.

Example

The following code example demonstrates the use of a custom ObjRef. To view the activation code that tests the custom ObjRef, see the example for the RemotingConfiguration.RegisterWellKnownServiceType method.

// a custom ObjRef class that outputs its status
public class MyObjRef : ObjRef {
   
   // only instantiate via marshaling or deserialization
   private MyObjRef() { }

   public MyObjRef(MarshalByRefObject o, Type t) : base(o, t)  {
      Console.WriteLine("Created MyObjRef.");
      ORDump();
   }

   public MyObjRef(SerializationInfo i, StreamingContext c) : base(i, c) {
      Console.WriteLine("Deserialized MyObjRef.");
   }

   public override void GetObjectData(SerializationInfo s, StreamingContext c) {
      // After calling the base method, change the type from ObjRef to MyObjRef
      base.GetObjectData(s, c);
      s.SetType(GetType());
      Console.WriteLine("Serialized MyObjRef.");
   }

   public override Object GetRealObject(StreamingContext context) {

      if ( IsFromThisAppDomain() || IsFromThisProcess() ) {
         Console.WriteLine("Returning actual object referenced by MyObjRef.");
         return base.GetRealObject(context);
      }
      else {
         Console.WriteLine("Returning proxy to remote object.");
         return RemotingServices.Unmarshal(this);
      }
   }   

   public void ORDump() {

      Console.WriteLine(" --- Reporting MyObjRef Info --- ");
      Console.WriteLine("Reference to {0}.", TypeInfo.TypeName);
      Console.WriteLine("URI is {0}.", URI);
      Console.WriteLine("\nWriting EnvoyInfo: ");

      if ( EnvoyInfo != null) {
         
         IMessageSink EISinks = EnvoyInfo.EnvoySinks;
         while (EISinks != null) {
            Console.WriteLine("\tSink: " + EISinks.ToString());  
            EISinks = EISinks.NextSink;
         }
      }
      else
         Console.WriteLine("\t {no sinks}");

      Console.WriteLine("\nWriting ChannelInfo: ");
      for (int i = 0; i < ChannelInfo.ChannelData.Length; i++)
         Console.WriteLine ("\tChannel: {0}", ChannelInfo.ChannelData[i]);
      Console.WriteLine(" ----------------------------- ");
   }
}


// a class that uses MyObjRef
public class LocalObject : MarshalByRefObject {
   // overriding CreateObjRef will allow us to return a custom ObjRef
   public override ObjRef CreateObjRef(Type t) {
      return new MyObjRef(this, t);
   }
}

System.Runtime.Remoting.ObjRef Member List:

Public Constructors

ctor #1	Overloaded: `.ctor()`Default constructor. This constructor is called by derived class constructors to initialize state in this type. Initializes a new instance of the ObjRef class with default values.
ctor #2	Overloaded: `.ctor(MarshalByRefObject o, Type requestedType)` Initializes a new instance of the ObjRef class to reference a specified MarshalByRefObject of a specified Type.

Public Properties

ChannelInfo	Read-write Gets or sets the IChannelInfo for the ObjRef.
EnvoyInfo	Read-write Gets or sets the IEnvoyInfo for the ObjRef.
TypeInfo	Read-write Gets or sets the IRemotingTypeInfo for the object that the ObjRef describes.
URI	Read-write Gets or sets the URI of the specific object instance.

Public Methods

Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetHashCode (inherited from System.Object)	See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects.
GetObjectData	Populates a specified SerializationInfo with the data needed to serialize the current ObjRef instance.
GetRealObject	Returns a reference to the remote object that the ObjRef describes.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
IsFromThisAppDomain	Returns a Boolean value indicating whether the current ObjRef instance references an object located in the current AppDomain.
IsFromThisProcess	Returns a Boolean value indicating whether the current ObjRef instance references an object located in the current process.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Constructors

ctor #3 Overloaded:
.ctor(SerializationInfo info, StreamingContext context) Initializes a new instance of the ObjRef class from serialized data.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

System.Object

System.Runtime.Remoting.ObjRef

System.Runtime.Remoting.ObjRef Member Details

Overloaded ctor #1

Summary: Initializes a new instance of the ObjRef class with default values.

Default constructor. This constructor is called by derived class constructors to initialize state in this type.

C# Syntax:


            public ObjRef();