This method is used to attach a message handle created outside of
the class using the SocketTools API. Once the handle is attached to
the class, the other class member functions may be used with that
message.
If a message handle already has been created for the class, that
handle will be released when the new handle is attached to the class
object. If you want to prevent the previous message from being
destroyed, you must call the DetachHandle method. Failure to
release the detached handle may result in a resource leak in your
application.
Note that the hMessage parameter is presumed to be a valid
message handle and no checks are performed to ensure that the handle
is valid. Specifying an invalid message handle will cause subsequent
method calls to fail.