Can someone point out the most common roadblocks when migrating a .net 2.0 app to framework 4.0, if any? (I would expect backwards compatibility, but who knows!)
I need to estimate the effort of making an asp.net 2.0 app run in framework 4.0 with as few code changes as possible.
Thanks in advance!
When i upgraded an old intranet site from 2.0 to 4.0 the only thing that broke was Crystal Reports.
The site was medium size and nothing was found to have been broken, it has now been about 3 months since then and nothing has been reported as of yet, so it should be fine unless you have some 3rd party libraries that depends on legacy code in .net 2.0 which would require you to have an extra line in the web.config to allow access to legacy 2.0.
<startup useLegacyV2RuntimeActivationPolicy="true|false" >
There are very few (if any) issues in upgrading .NET versions. The biggest problems you might face is migrating Visual Studio versions, but even that's usually painless.
You could even go back to an older version of .NET if you want - obviously then you'll need code changes to remove any new features you've used.
I've upgraded multiple projects from 2.0 to 3.5, and then from 3.5 to 4. I never had a single problem with the upgrades. I did like to first upgrade the solution from 2005 to 2010 first and then actually change the framework version, but you may get better mileage with a different method.