O'Reilly logo

Microsoft® Windows® Communication Foundation Step by Step by John Sharp

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Using a Callback Contract to Implement Events

One of the principal uses of a callback contract is to provide a service with a means to inform a client application of a significant occurrence. You can use callbacks to implement an eventing mechanism; the service can advertise events and provide operations to enable client applications to subscribe to these events or unsubscribe from them. The service can use the callback contract to send a message to each subscribing client when an event occurs. You will see how to do this later, but first you need to define, implement, and test a callback contract that can act as the basis for an eventing mechanism.

Add a callback contract to the ProductsService service and invoke a callback operation

  1. Using Visual ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required