Access internal classes for inherited type

Question

Looking to extend the BeginReceive method, and the event handler for MessageQueue.ReceiveCompleted to pass along by REFERENCE a TCPClient object. As is, I can pass it in as an object, but it will be by VALUE, and therefore will be a copy of the TCPClient object. No good!

So, I decided to try and write my own overloaded methods, etc. Debugging into the .NET 4.5.2 Framework code, I see that BeginReceive(TimeSpan timeout, object stateObject) returns:

ReceiveAsync(timeout, CursorHandle.NullHandle, NativeMethods.QUEUE_ACTION_RECEIVE, null,
             stateObject);

The problem is that CursorHandle and NativeMethods seem to be in System.Messaging.Interop namespace, but since all those classes are declared as "internal" I can't seemingly access them. (Yes - I downloaded the .NET Framework C# code). Is there any quick way to access this stuff?

Answer 1

TCPClient is a class and therefore a reference type. Parameters and variables of this type contain a reference to an object. In this case ByVal means that this reference is passed by value, not the object.

The TCPClient object will not be copied!

---

Note that you can also pass a reference ByRef. In this case you are dealing with a reference to a reference to an object. What this means is that if you assign a new object to such a parameter in a method, this changes the variable used as method argument. If the parameter was ByVal it would not change this variable, as the method parameter would contain a copy of the reference (but not a copy of the object).

In both cases, if you change a property of the object in the method, it will change the original object, since it is the identical object.

Call Method(ByVal variable)

                              +---------+
                              |         |
        variable +----------> | Object  |
                              |         |
                              +---+-----+
                                  ^
        Sub Method (ByVal p)      |
            p  +------------------+        'If you change p here, it does NOT change variable.
        End Sub

Call Method(ByRef variable)

                              +---------+
                              |         |
+-----> variable +----------> | Object  |
|                             |         |
|                             +---------+
|
|       Sub Method (ByRef p)
+---------+ p                              'If you change p here, it DOES change variable.
        End Sub