.Net Remoting, I have to use marshal by reference in this case?

steven

15y4.3k.NET

//remotable object
[Serializable]
public class MBV
{
public int Data
{
get;
set;
}
}
public class MBR : MarshalByRefObject
{
public int Data
{
get;
set;
}
}

//server side
//ellipsis

//client side
//create channel/object etc...

MyObject obj = (MyObject)Activator.GetObject(typeof(MyObject), "tcp://localhost:2222/myObj");

obj.Mbv = new MBV();
obj.Mbv.Data = 1112; //It seems no effect of this statement for marshalByValueObject.
Console.WriteLine(obj.Mbv.Data);

obj.Mbr = new MBR();
obj.Mbr.Data = 1112;
Console.WriteLine(obj.Mbr.Data);

//OUTPUT,
0
1112

How can i change the data of marshalByValueObject? I have to use marshal by reference in this case?

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes15y ago
Accepted answer
When a remote application accesses a marshal by value object, a copy of the object is passed to the remote application. As it's a copy, any changes which the latter makes to the object are not persisted back to the local application.

However, when a remote application accesses a marshal by reference object, a proxy is passed to the remote application. Any changes which the latter makes to the proxy object are then marshalled back to the local object.

The situation is analogous to passing parameters by value or reference to a method, even though a different mechanism is at work.

So, the answer to your question is that, if you want changes to be persisted to the local object, you must inherit from MarshalByRefObject.
steven15y ago
Vulpes, Much thanks for your quick reply.

I use SOS debug look into it, once the obj.Mbv.Data executes, a new MBV instance created(a copy created), and i can see the value 1112 there. It demonstrates all you wrote. Thanks again!