18.4 Performing Client-Side Activation of Remotable Objects

You want to use stateful remoting objects with .NET Remoting.

Technique

To keep state in the remote object, it is just necessary to register the remote object as a client-activated object with the method RegisterActivatedServiceType after the channel is registered:

 RemotingConfiguration.RegisterActivatedServiceType(         typeof(_1_RemoteObject.RemoteObject)); 

With the client application, you can use the CreateInstance method of the Activator class with client-activated objects.

With the client application, you can use either the Activator class or the class RemotingConfiguration to configure the client-activated object type. With the Activator class, you use the method GetObject with well-known objects, but with client-activated objects, you need the method CreateInstance . With this method, you can pass arguments to a nondefault constructor ( null in this example) and attributes. With the attributes, you have to set the URL to the remote object:

 object[] attrs = { new UrlAttribute("tcp://localhost:8088/Demo") }; _1_RemoteObject.RemoteObject obj =         (_1_RemoteObject.RemoteObject)Activator.CreateInstance(                 typeof(_1_RemoteObject.RemoteObject), null, attrs); 

A second way to instantiate client-activated objects is to use the RemotingConfiguration class with the method RegisterActivatedClientType . This way, you can use the new operator to instantiate the remote object, as discussed before:

 RemotingConfiguration.RegisterActivatedClientType(         typeof(_1_RemoteObject.RemoteObject),         "tcp://localhost:8088/Demo"); 

Comments

Using stateless objects is the preferred programming model with distributed solutions. With stateful objects, the server has allocated resources for a client.

With stateful objects, be aware that the objects are destroyed on the server after a timeout of a leasing time. The leasing mechanism is discussed in Recipe 18.9, "Controlling Lifetime Leases."