The registry is the official way to detect if a specific version of the Framework is installed.
Which registry keys are needed change depending on the Framework version you are looking for:
Framework Version Registry Key
------------------------------------------------------------------------------------------
1.0 HKLM\Software\Microsoft\.NETFramework\Policy\v1.0\3705
1.1 HKLM\Software\Microsoft\NET Framework Setup\NDP\v1.1.4322\Install
2.0 HKLM\Software\Microsoft\NET Framework Setup\NDP\v2.0.50727\Install
3.0 HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.0\Setup\InstallSuccess
3.5 HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.5\Install
4.0 Client Profile HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Client\Install
4.0 Full Profile HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Full\Install
Generally you are looking for:
"Install"=dword:00000001
except for .NET 1.0, where the value is a string (REG_SZ
) rather than a number (REG_DWORD
).
Determining the service pack level follows a similar pattern:
Framework Version Registry Key
------------------------------------------------------------------------------------------
1.0 HKLM\Software\Microsoft\Active Setup\Installed Components\{78705f0d-e8db-4b2d-8193-982bdda15ecd}\Version
1.0[1] HKLM\Software\Microsoft\Active Setup\Installed Components\{FDC11A6F-17D1-48f9-9EA3-9051954BAA24}\Version
1.1 HKLM\Software\Microsoft\NET Framework Setup\NDP\v1.1.4322\SP
2.0 HKLM\Software\Microsoft\NET Framework Setup\NDP\v2.0.50727\SP
3.0 HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.0\SP
3.5 HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.5\SP
4.0 Client Profile HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Client\Servicing
4.0 Full Profile HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Full\Servicing
[1] Windows Media Center or Windows XP Tablet Edition
As you can see, determining the SP level for .NET 1.0 changes if you are running on Windows Media Center or Windows XP Tablet Edition. Again, .NET 1.0 uses a string value while all of the others use a DWORD.
For .NET 1.0 the string value at either of these keys has a format of #,#,####,#. The last # is the Service Pack level.
While I didn't explicitly ask for this, if you want to know the exact version number of the Framework you would use these registry keys:
Framework Version Registry Key
------------------------------------------------------------------------------------------
1.0 HKLM\Software\Microsoft\Active Setup\Installed Components\{78705f0d-e8db-4b2d-8193-982bdda15ecd}\Version
1.0[1] HKLM\Software\Microsoft\Active Setup\Installed Components\{FDC11A6F-17D1-48f9-9EA3-9051954BAA24}\Version
1.1 HKLM\Software\Microsoft\NET Framework Setup\NDP\v1.1.4322
2.0[2] HKLM\Software\Microsoft\NET Framework Setup\NDP\v2.0.50727\Version
2.0[3] HKLM\Software\Microsoft\NET Framework Setup\NDP\v2.0.50727\Increment
3.0 HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.0\Version
3.5 HKLM\Software\Microsoft\NET Framework Setup\NDP\v3.5\Version
4.0 Client Profile HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Version
4.0 Full Profile HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Version
[1] Windows Media Center or Windows XP Tablet Edition
[2] .NET 2.0 SP1
[3] .NET 2.0 Original Release (RTM)
Again, .NET 1.0 uses a string value while all of the others use a DWORD.
Additional Notes
for .NET 1.0 the string value at either of these keys has a format of #,#,####,#
. The #,#,####
portion of the string is the Framework version.
for .NET 1.1, we use the name of the registry key itself, which represents the version number.
Finally, if you look at dependencies, .NET 3.0 adds additional functionality to .NET 2.0 so both .NET 2.0 and .NET 3.0 must both evaulate as being installed to correctly say that .NET 3.0 is installed. Likewise, .NET 3.5 adds additional functionality to .NET 2.0 and .NET 3.0, so .NET 2.0, .NET 3.0, and .NET 3. should all evaluate to being installed to correctly say that .NET 3.5 is installed.
.NET 4.0 installs a new version of the CLR (CLR version 4.0) which can run side-by-side with CLR 2.0.
Update for .NET 4.5
There won't be a v4.5
key in the registry if .NET 4.5 is installed. Instead you have to check if the HKLM\Software\Microsoft\NET Framework Setup\NDP\v4\Full
key contains a value called Release
. If this value is present, .NET 4.5 is installed, otherwise it is not. More details can be found here and here.
If I understand correctly, your list has the same type parameter as the container class itself. If this is the case, then:
Type typeParameterType = typeof(T);
If you are in the lucky situation of having object
as a type parameter, see Marc's answer.
Best Answer
This actually has a surprisingly tricky answer.
First of all, to get this functionality that is outline in the following post you will need either the latest version of fxcop or VS 2008 SP1.
Once you have that installed there is a new rule (in VS 2008 Team System) called Portability Rules -> Use only API from targeted framework.
But that is not enough
Fxcop is currently shipping with dodgy wpf rules:
Quote from the last line in the above post:
So you will need to crack open cmd in admin and fix up those files if you want this to work.
Once that is done, it seems to work fine.