Asynchronous Invocation

• The genrated stubs have two methods that allow one to call web services asynchronously.

class proxy {
  ...
  public System.IAsyncResult BeginDelay(System.AsyncCallback callback,
                                        object asyncState){
  return this.BeginInvoke("Delay", new object[0], callback, asyncState);
}
  public int EndDelay(System.IAsyncResult asyncResult){
    object[] results = this.EndInvoke(asyncResult);
    return((int)(results[0]));
  }
}

• Start by calling BeginDelay. It returns an object that allows us to check if the request has been done.