Question

I know all about threading applications, but haven’t done this over web services before. Rather than have the client manage various threads, I want to just fire an async method and get the result from a callback.

It looks straight forward enough – just call the async method in the proxy class generated by visual studio. BUT WAIT… there isn’t anywhere for me to specify a call back.

MSDN and other sites tell me I should be using Begin[MethodName] and End[MethodName], but they don’t appear to exist/been-generated, I do have the [MethodName]Async method which is good (see here), but it doesn’t have an option to pass in a delegate/callback.

I also have (staticly) ServiceName.MethodNameEventHandler/Args available, but can’t use it as it isn’t part of the instantiated service.

What is going on? and how can I send/receive a call back from a web service. I have noticed all the googling I’ve done provides me with pretty old sites. Can anyone provide me with an example.

Answer 1

If you have [MethodName]Async methods, you should have [MethodName]Completed events, which you can subscribe to, and that will act as your callback.

In vb.net it should be something like this:

AddHandler yourWebProxyClassInstance.[MethodName]Completed, AddressOf YourMethod