问题

SUMMARY

How do I create a publisher policy assembly that targets the same framework version as the redirected assembly?

TL;DR

I have an Assembly.dll with version 1.x.y.0 and I also have a publisher policy for it named policy.1.0.Assembly.dll which redirects versions 1.0.0.0-1.x.y.0 to 1.x.y.0.

The Assembly.dll targets .NET Framework 3.5. Am I right in thinking that the policy.1.0.Assembly.dll should also target .NET Framework 3.5 for things to work correctly on all frameworks 3.5+? If yes, how do I go about creating such a publisher policy assembly? I cannot see any relevant command line switch on the Assembly Linker (AL).

Currently when I GAC the assemblies, Assembly.dll ends up in \Windows\assembly and policy.1.0.Assembly.dll ends up in \Windows\Framework.NET\assembly. ILDASM shows me that the targeted runtimes are different:

Assembly.dll:

// Metadata version: v2.0.50727
.assembly extern mscorlib
{
  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )                         // .z\V.4..
  .ver 2:0:0:0
}
.assembly extern System
{
  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )                         // .z\V.4..
  .ver 2:0:0:0
}

policy.1.0.Assembly.dll:

// Metadata version: v4.0.30319
.assembly extern mscorlib
{
  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )                         // .z\V.4..
  .hash = (B6 24 5D 64 2D 23 95 0B 50 19 B4 DC 19 4B 9A E8   // .$]d-#..P....K..
           B9 FF C0 53 )                                     // ...S
  .ver 4:0:0:0
}

回答1:

Using the Assembly Linker from C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin appears to produce a policy.1.0.Assembly.dll that targets the correct runtime:

// Metadata version: v2.0.50727
.assembly extern mscorlib
{
  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )                         // .z\V.4..
  .hash = (15 3B C0 4F 38 2D 09 20 CC A2 58 01 EE B1 AB E2   // .;.O8-. ..X.....
           D2 D0 C5 11 ) 
  .ver 2:0:0:0
}

While this appears to do what I want, it is unclear whether: