Why can't I edit my ASP.NET Web application at run time?

Question

Why are the code-behind pages for an ASP.NET web application locked at run time? I have older projects (probably defined as "web sites" instead of "web apps") where I can edit the code behind, refresh the browser, and see my changes. With the web app, I have to continually close and reopen the browser if I want to see my changes live. Is there a setting or something I'm missing to allow me to edit at run time, and without restarting the debugging session?

Answer 1

You can enable Edit and Continue in the project properties. Right click the project in the solution explorer, select the Web tab and check Enable Edit and Continue.

Now you can edit your sources, but you have to pause the debugger to do so.

Answer 2

When using IIS as your development server, Edit and continue is not currently available for Visual Studio for ASP.NET.

See this blog entry , however, that shows it is possible for the Visual Studio 2005 Web Application Project Project type. It requires using the Visual Studio Development Server (Cassini) during development instead of your local IIS (see the properties box on the project).

Answer 3

No, in web applications, the codebehinds are pre-compiled into dlls, so any change in the dlls will recycle the App pool, and stop your debugging session,

If you press ctrl-F5 instead of just F5 to start (or host you site in IIS), you start without the debugger, and don't need to restart the browser all the time...

Unless you really really need to debug a problem you can't figure out, You should start the web app without debugger, makes it snappier to start up. Every minute spent debugging is a minute not spent writing a unit test. IMHO you should write unit tests, they last longer.