BTW, the [OneWay] attribute you have applied to your client code:
> public class TheClient
> {
> public delegate string MyDelegate();
> public static ManualResetEvent e;
>
> [OneWayAttribute]
> public static void MyCallBack(IAsyncResult ar)
> {
> MyDelegate d =
> (MyDelegate)((AsyncResult)ar).AsyncDelegate;
> Console.WriteLine(d.EndInvoke(ar));
> e.Set();
> }
>
isn't doing anything and is unncessary. The [OneWay] attribute is
applied to methods that are to be called via remoting across process
boundaries, and causes the sending channel to skip waiting for a reply
message and the receiving channel to skip sending an reply message. In
your code, MyCallback is just a local method that's being called by the
in-process thread pool once the async delegate invocation the local
TimeConsumingRemoteCall method on the proxy returns.
Your use of BeginInvoke isn't really specific to remoting. You're just
using a local thread pool thread to call the TimeConsumingRemoteCall
method on the proxy, which takes a "long" time to return. You don't
want to block yourself for that amount of time, so you're borrowing a
thread from the thread pool to do the job (ostensibly so you can go do
other things in the meantime). When that thread returns from its call
to TimeConsumingRemoteCall, it will then invoke TheClient.MyCallback to
let you know the call completed.
Also, you might have just wanted to familiarize yourself with how to use
BeginInvoke to request a callback when the method completes, but if you
want to block yourself until that call completes, you don't need to go
to the trouble of creating & signaling a manual reset event. That
functionality is built-in to the IAsyncResult interface.
IOW, instead of doing this:
IAsyncResult ar = d.BeginInvoke(cb, null);
// do other things
e.WaitOne();
where e is a reference to a ManualResetEvent that's signaled by the
callback referred to by 'cb', you can instead just do this:
IAsyncResult ar = d.BeginInvoke(null, null);
// do other things
ar.AsyncWaitHandle.WaitOne();
If the entire point of your callback is to signal an event telling you
the call completed, you can just skip that altogether and use the
built-in mechanism for waiting until the call completes.
-Mike
DevelopMentor
http://staff.develop.com/woodring
