Introduction

Chapter 13 prepared you to do anything possible with Web Services. If there is some fundamental thing that you do not completely grasp, you know enough about Web Services to track down any minute detail. We are ready to discuss advanced concepts.

This chapter shows you everything about Web Services that has been invented so far. In this chapter you will learn how to write Web Services that return simple and complex data types and how to modify the WSDL proxy files that describe complex types returned by Web Services. You will learn about returning an ADO.NET DataSet object from a Web Service and about the mechanism that makes it possible to do so, XML. By the time you are finished reading you will have mastered invoking Web Services synchronously and asynchronously (which is not possible without multithreading), and you will know how to block, poll, and wait for asynchronous Web method calls to return. Finally, I will demonstrate a way ”in addition to using Windows Authentication ”to secure your Web Services. In short, by the time you have finished this chapter you will be well equipped to make XML Web Services an integral part of your development arsenal.

I will begin the chapter with a synchronous Web Service that returns simple data and end the chapter with asynchronous Web Services. As a result I believe that when you are finished reading the chapter you will feel comfortable speaking competently with gurus about XML Web Services.