BradleyB's WebLog

1. Move App_Code files into a separate class library project and reference it form the web site project.  This will improve build performance and provide all compilation errors for these class files within the IDE.
2. Add a Web Deployment Project to the solution.  Configure the Web Deployment project so that it only builds for the release configuration.  This will allow you to completely validate the site before deployment without compromising the performance of the edit/run iterations under the debug configuration.

Move App_Code files into a separate class library project
I'm repeating this tip because even if you don't change the default build options you can improve build performance by moving the files from App_Code into a separate class library project.

Check for conflicting dependencies
If you do have conflicting dependencies, the web site project will do a full clean rebuild on every build even if only a page changes.  The problem is when you add a file based references that have a common dependency but to different versions of that dependency.   A file based references have a .dll.refresh file in the bin folder.  The .refresh file has the path to the original assembly.  These paths are checked on every build.

In this example we have two assemblies, A.dll and B.dll both dependent on Foo.dll.

    A.dll -> dependent on Foo.dll
    B.dll -> dependent on Foo.dll

When A.dll is refreshed the project system will discover the dependency on Foo.dll and copy it into bin. Likewise when B.dll is refreshed Foo.dll will be copied if different than the one already in bin. The problem is that when a class library is built by a class library project in VS it caches the dependencies. So as you can see here Class Libraries A and B both have a private copy of Foo.

ClassLibraryA
    A\bin\debug\A.dll
    A\bin\debug\Foo.dll

ClassLibraryB
    B\bin\debug\B.dll
    B\bin\debug\Foo.dll

ClassLibraryFoo
    Foo\bin\debug\Foo.dll

If ClassLibraryFoo is updated and only ClassLibraryB is recompiled then ClassLibraryB has a updated copy for Foo.dll but ClassLibraryA does not. When the web project is built, the refresh of A is copying in it's copy of Foo and the refresh of B is copying in it's copy. Each time Foo is copied because it's different than the one already in bin.

Because the bin is changing with every VS build the ASP.Net compilation cache is invalidated forcing a full build.  Thus every build is a full build.

To fix this problem do one of the following:

1. Add class libraries A,B and Foo to the same solution as the web site and replace the file base references with project references.
2. Always build all consumers of a dependency when the dependency changes.
3. Remove the .refresh files and manually update as needed.

Turn off AutoToolboxPopulate in the Windows Forms Designer options. 
Some user have reported a hang during build.  This was resolve by turning off AutoToolboxPopulate.
http://forums.asp.net/1108115/ShowPost.aspx

    Tools/Options/Windows Forms Designer/General/AutoToolboxPopulate = False

Disable validation for HTML editing
By default the HTML/ASPX editor performs html validation in the background while the file is open.  This does not normally impact performance unless there are numerous error to report.  So if you're already compliant, turning it off won't save you much but if you do have errors and don’t' need to fix them, turning if off can make a difference. 
http://msdn2.microsoft.com/en-us/library/0byxkfet.aspx


You'll be surprised at the performance improvement these changes will make for the edit/run iterations of your daily workflow.  My sample solution with 2 class libraries and 1 web site went from 17 seconds to build to less than a second.  While these techniques may not be right for every project, the improvements are significant enough that you should try them out and evaluate them for yourself.

Hope this helps,
Brad.