You will see that the proxy class provides two other methods besides ToFahrenheit. If a client uses the proxy class's ToFahrenheit method, it will sit there waiting for the Web Service's webserver to reply. If, instead, the client uses the BeginToFahrenheit method of the proxy class, the call of BeginToFahrenheit will return almost immediately. In the client, the call of BeginToFahrenheit has to supply (in an argument) the method that it wants to be called when the webserver delivers its reply. That method will need to call EndToFahrenheit to get the result of the call of ToFahrenheit.

• To summarise: a programmer wishing to use a Web Service provided by some site only has to provide Visual Studio.NET's wizard with the URL of the Web Service.
• Having done that, the wizard generates a proxy class that the programmer can use.
• If you are not using Visual Studio.NET, you can instead use wsdl.exe (which is part of the .NET Framework (and is free)).