This event is raised each time an asynchronous upload makes progress. This event is raised when uploads are started using any of the following methods.
Sends a byte array to the resource, without blocking the calling thread.
Sends a local file to the resource, without blocking the calling thread.
Sends a System.Collections.Specialized.NameValueCollection to the resource and returns a byte array containing any response, without blocking the calling thread.
For more information about handling events, see Consuming Events.