Hi !

Thanks for a great product to work with. One question i have though is: Is there currently any way to use DO 4 with NET 4 (RC)/Visual Studio 2010(RC) ?

I tried with manual setup of the project ( ie modifying the csproj files ) and this gets you to the point where everything "seems" to work but PostSharp crashes during build because it can't find a class in System.Security that was removed in NET 4.0

So i tried upgrading to PostSharp 2 which does not seem to work at all ( replaced PostSharp in Lib and modified all paths to the new files )

.. Any ideas on this ?

This thread was imported from our support forum. The original discussion may contain more detailed answer. Original topic by Gluber2010.

asked Feb 20 '10 at 14:47

Editor's gravatar image


One Answer:

Alex (Xtensive) wrote:

No, there is no such way, and, if you'd ask, I'd immediately reply this isn't easy:

  • There must be issues with PostSharp. In short, we must migrate to its latest version to deal with .NET 4.0.

  • Some of our type names conflict with new ones in .NET 4.0 - e.g. Tuple, Action\Func<with more="" than="" 5="" args="">, etc. Important, since you must rebuild DO4 to make it work with .NET 4.0.

  • .NET 4.0 brings few nice types eliminating the need of our own analogues for them - e.g. Lazy<t> (we have Cached<t> and ThreadSafeCached<t> in Core). So good we have them, but we must switch to standard ones during migration to v4.0.

Now the good news: we're going to provide .NET 4.0-ready version of DO4 before official release of VS.NET 2010, so .NET 4.0 support must be available in the nearest (post-v4.2) release. So far we aren't fully aware of complexity of this, but since Mono support is one of our nearby goals as well, we must do this very carefully. In fact, we must leave support for .NET 3.5 as well, + try to add Mono support. Although (obviously) .NET 4.0 support has the highest priority - i.e. we must do this in time.

mahdness wrote:


Could you please provide an accurate ETA on when VS2010/.NET4 support will be released?

We need to make some very important decisions on our end, and this greatly depends on the ETA.

Would it be possible just to release basic support first, and then focus on integrating all the other things you want to do (e.g. Mono, licensing, etc.)?

Alex (Xtensive) wrote:

v4.3 RC1 is uploading to http://www.x-tensive.com/Downloads/Defa ... bjects.Net - it will take about 10 min. to complete.


  • This build supports only .NET 4.0 and VS2010; .NET 3.5 version will be available on the next week.

  • You must uninstall old DO 4.X and old PostSharp (if you installed it);

  • This version will function for 60 days or till the end of July - which is earlier. During this period we'll migrate to full-featured licensing module.

  • There is no source code - only binaries.

To upgarde to this version from v4.2, you must:

  • Uninstall old v4.2 and install v4.3

  • Upgrade your projects to VS.NET 2010

  • Remove [Persistent(...)] attribute from your AssemblyInfo.cs files and reference to its namespace (Xtensive.Storage.Aspects).

  • Probably, add "using Xtensive.Core;" to some of your files - we moved classes from our "System" namespace to this one.

  • Likely, it will be necessary to make other minor fixes. Please notify us, if you'll notice another typical case.

Good luck! Shortly I'll make a detailed post about this in my blog.

answered Feb 22 '10 at 23:04

Editor's gravatar image


Issue to track: http://code.google.com/p/dataobjectsdot ... ail?id=507

Scheduled for v4.3, our next major update.

(Feb 22 '10 at 23:04) Alex Yakunin Alex%20Yakunin's gravatar image

I was finally managed to update our installation sctipts for this version today, that means we alreayd have working installer.

So v4.3 RC will be definitely published on this week. The build will get RC status mainly because it wasn't tested publically.

(Feb 22 '10 at 23:04) Alex Yakunin Alex%20Yakunin's gravatar image

The end of "this week" is nearing :wink:

Is it ready?

(Feb 22 '10 at 23:04) ara ara's gravatar image

Yep - we're fixing minor bugs in templates, etc. So it will be available in several hours.

(Feb 22 '10 at 23:04) Alex Yakunin Alex%20Yakunin's gravatar image
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