private void annotation_Click(object sender, RoutedEventArgs e) { ExceptionFriendly(() => { _context.SendingRequest2 += (requestSender, eventArgs) => { eventArgs.RequestMessage.SetHeader("Prefer", "odata.include-annotations=\"*\""); }; var people = WaitForResult(_context.People.ExecuteAsync()); var person = people.Single(p => p.UserName == "russellwhyte"); string annotationValue; if (_context.TryGetAnnotation(person, "TestAnnotation", "TestQualifier", out annotationValue)) { SetText($"Annotation on People('russellwhyte') is '{annotationValue}'."); } else { SetText("No annotation on People('russellwhyte')."); } }); }