Programming ASP.NET, Second Edition

Creating the Consuming Application

Once the proxy dll is created and placed in the bin subdirectory, then it is a simple matter to create the consuming application. All that is necessary is to add the necessary reference to that dll in the consuming application. This will be demonstrated for a web page created in a text editor and also for a web page created in Visual Studio .NET.

As long as the signatures and return types of the exposed web service methods do not change, the proxy will continue to work. The signature of a web method consists of the name of the method and its parameter list and return value.

The web service can have additional web methods added without breaking the proxy, although the new web methods will not be visible to the consuming application until the proxy source code is regenerated and recompiled. Likewise, existing web methods can have their underlying code modified, but as long as their signature does not change, the proxy will still work fine.

Using a Text Editor

To create a web page that will consume a web service, create a normal ASP.NET web page. Then create a bin subdirectory immediately below the directory containing the .aspx file. Put the compiled proxy dll in the bin directory. Then in the source code of the web page, instantiate the proxy class. This is either done in the script block of the .aspx file, if it is coded inline, or just inside the class definition, if it uses a code-behind class.

Example 17-4 and Example 17-5 show a consuming web ...