ObjRef Class

 

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

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

System.Object
  System.Runtime.Remoting.ObjRef

[SerializableAttribute]
[SecurityCriticalAttribute]
[ComVisibleAttribute(true)]
[SecurityPermissionAttribute(SecurityAction.InheritanceDemand, 
	Flags = SecurityPermissionFlag.Infrastructure)]
public class ObjRef : IObjectReference, ISerializable

NameDescription
System_CAPS_pubmethodObjRef()

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

System_CAPS_pubmethodObjRef(MarshalByRefObject, Type)

Initializes a new instance of the ObjRef class to reference a specified MarshalByRefObject of a specified Type.

System_CAPS_protmethodObjRef(SerializationInfo, StreamingContext)

Initializes a new instance of the ObjRef class from serialized data.

NameDescription
System_CAPS_pubpropertyChannelInfo

Gets or sets the IChannelInfo for the ObjRef.

System_CAPS_pubpropertyEnvoyInfo

Gets or sets the IEnvoyInfo for the ObjRef.

System_CAPS_pubpropertyTypeInfo

Gets or sets the IRemotingTypeInfo for the object that the ObjRef describes.

System_CAPS_pubpropertyURI

Gets or sets the URI of the specific object instance.

NameDescription
System_CAPS_pubmethodEquals(Object)

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

System_CAPS_protmethodFinalize()

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

System_CAPS_pubmethodGetHashCode()

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

System_CAPS_pubmethodGetObjectData(SerializationInfo, StreamingContext)

Populates a specified SerializationInfo with the data needed to serialize the current ObjRef instance.

System_CAPS_pubmethodGetRealObject(StreamingContext)

Returns a reference to the remote object that the ObjRef describes.

System_CAPS_pubmethodGetType()

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

System_CAPS_pubmethodIsFromThisAppDomain()

Returns a Boolean value that indicates whether the current ObjRef instance references an object located in the current AppDomain.

System_CAPS_pubmethodIsFromThisProcess()

Returns a Boolean value that indicates whether the current ObjRef instance references an object located in the current process.

System_CAPS_protmethodMemberwiseClone()

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

System_CAPS_pubmethodToString()

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

A ObjRef is a serializable representation of an object that extends MarshalByRefObject (MBR). A ObjRef is used to transfer an object reference across a AppDomain boundary. Creating a ObjRef for an object is known as marshaling. You can create a 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 application domain, possibly in another process or computer. When the ObjRef is deserialized (see XML and SOAP Serialization) in the target application domain, 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 a 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.

This class makes a link demand and an inheritance demand at the class level. A SecurityException is thrown when either the immediate caller or the derived class does not have infrastructure permission. For details about security demands, see Link Demands and Inheritance Demands.

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 RegisterWellKnownServiceType method.

// a custom ObjRef class that outputs its status
[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
public class MyObjRef : ObjRef {

   // only instantiate using 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
[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
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);
   }
}

SecurityPermission

for operating with infrastructure code. Demand value: SecurityAction.LinkDemand; Permission Value: SecurityPermissionFlag.Infrastructure

SecurityPermission

for operating with infrastructure code. Demand value: SecurityAction.InheritanceDemand; Permission Value: SecurityPermissionFlag.Infrastructure

.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
Show: