Visual Studio Web Applications—Visual Studio Debugging
Microsoft .NET Framework, ASP.NET, Visual C# (CSharp, C Sharp, C-Sharp) Developer Training, Visual Studio
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| © 2006 M. MacDonald, M. Szpuszta |
Visual Studio Debugging
Visual Studio has always provided robust tools for debugging your web applications. In Visual Studio 2005, these tools remain essentially the same, with some minor enhancements that make it easier to drill into live objects and collections at runtime.
To debug a specific web page in Visual Studio, select that web page in the Solution Explorer, and click the Start Debugging button on the toolbar. (If you are currently editing the web page you want to test, you don’t need to select it at all—just click Start Debugging to launch it directly.)
What happens next depends on the location of your project. If your project is stored on a remote web server or a local IIS virtual directory, Visual Studio simply launches your default browser and directs you to the appropriate URL. If you’ve used a file system application, Visual Studio starts its integrated web server on a dynamically selected port (which prevents it from conflicting with IIS, if it’s installed). Then Visual Studio launches the default browser and passes it a URL that points to the local web server. Either way, the real work—compiling the page and creating the page objects—is passed along to the ASP.NET worker process.
Tip Visual Studio’s built-in web server allows you to retrieve a file listing. This means if you create a web application named MyApp, you can make a request in the form of http://localhost:port/MyApp to see a list of pages. Then, just click the page you want to test. This process assumes your web application doesn’t have a default.aspx page—if it does, any requests for the website root automatically return this page.
The separation between Visual Studio, the web server, and ASP.NET allows for a few interesting tricks. For example, while your browser window is open, you can still make changes to the code and tags of your web pages. Once you’ve completed your changes, just save the page, and click the Refresh button in your browser to rerequest it. Although you’ll always be forced to restart the entire page to see the results of any changes you make, it’s still more convenient than rebuilding your whole project.
Fixing and restarting a web page is handy, but what about when you need to track down an elusive error? In these cases, you need Visual Studio’s debugging smarts, which are described in the next few sections.
Note When you use the test web server, it runs all code using your user account. This is different from the much more limited behavior you’ll see in IIS, which uses a less-privileged account to ensure security. It’s important to understand the difference, because if your application accesses protected resources (such as the file system, a database, the registry, or an event log), you’ll need to make sure you explicitly allow the IIS user.
 
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