Visual Basic.NET How to Program (PDF)

Chapter 21 ASP .NET and Web Services 1095
21.2 a) SOAP message. b) WebService. c) code-behind. d) WebClient. e) HTTP.
f) Description. g) XML serialization. h) domain.
EXERCISES
21.3 Create a Web service that stores phone-book entries in a database. Give the user the capability
to enter new contacts and to find contacts by last name. Pass only primitive types as arguments to
the Web service.
21.4 Modify Exercise 21.3 so that it uses a class named PhoneBookEntry. The client application
should provide objects of type PhoneBookEntry to the Web service when adding contacts and
should receive objects of type PhoneBookEntry when searching for contacts.
21.5 Modify the Blackjack Web service example in Section 21.5 to include a class Card. Have
DealCard return an object of type Card. Also have the client application keep track of what cards
have been dealt, using Cards. Your card class should include properties to determine the face and
suit of the card.
21.6 Modify the airline reservation example in Section 21.6 so that it contains two separate Web
methods—one that allows users to view all available seats, and another that allows them to reserve
seats. Use an object of type Ticket to pass information to and from the Web service. This Web application
should list all available seats in a ListBox and then allow the user to click a seat to reserve
it. Your application must be able to handle cases where two users view available seats, one reserves
a seat, and then the second user tries to reserve the same seat not knowing that the database has
changed since the page was loaded.
21.7 Modify the TemperatureServer example in Section 21.7 so that it returns an array of
CityWeather objects that the client application uses to display the weather information.
21.8 Modify the Web service in the math-tutor example in Section 21.8 so that it includes a method
that calculates how “close” the player is to the correct answer. The client application should provide
the correct answer only after a user has offered numerous answers that were far from the correct
one. Use your best judgement regarding what constitutes being “close” to the right answer. Remember
that there should be a different formula for 1-digit, 2-digit and 3-digit numbers. Also, give the
program the capability to suggest to users that they try a lower difficulty level if the users are consistently
wrong.