Building VS2008 projects in VS2005

Today I got reminded of one issue, that I did not mention in the previous post on VS2005 solutions and projects conversion to VS2005 (mostly because I was not aware of that at the time :).

As it is .Net projects created in VS2005 can be built both in 2005 and 2008 without any changes to the project file. However, should you create a new project in VS2008 (even one targeting .Net 2.0), you will not be able to build it in VS2005. The reason is that VS2008 project is created compliant with MSBuild 3.5, in which $(MSBuildBinPath) property (location of all system target files) is deprecated, and $(MSBuildToolsPath) is used instead. Thus VS2008 will use MSBuildToolsPath to specify the location of Microsoft.CSharp.targets file, and the project will promptly blow in VS2005 on build.

As far as I know, there is no elegant solution to this problem (short of changing the project file). Probably the easiest solution would be to create the projects in VS2005 (that is, if you want to have .Net 2.0 projects that can be opened in both versions of Visual Studio). If you do modify the project files, here is the snippet I use to make sure that the project can be built in both flavours of Visual Studio:

<!-- VS2008 original import (sans condition 

     which is added for VS2005 benefit) -->

<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" 

        Condition="$(MSBuildToolsPath) != ''" />

<!-- VS2005 import - added for VS2005 compatibility 

     (since there is no ToolsPath there) -->

<Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" 

        Condition="$(MSBuildToolsPath) == ''" />

Footnote: once you decide to use .Net 3.5 in your project on VS2008, then obviously your project wont build in VS2005 no matter the modifications.