How to add manifest to a .NET DLL?

Question

I have a c# class library project that uses a COM dll registered on the system. I now want to deploy the COM dll as a side-by-side assembly, so I don't have to register it, or interfere with other applications that might use a different version of the dll.

I have added app.manifest to the c# project using the add new item menu, but I'm not sure what to do next. In the project properties/application/icon and manifest, the manifest drop down is disabled. I don't know how to get past that. I've added a manifest file, why is it not in the dropdown list?

I have a manifest for the COM dll that works with C++ applications, and I think I keep that as is. Now I need to know how to edit the app.manifest for the c# project. I will start by adding a known good dependency element. But I need a tutorial on how to set this up, I don't see it covered anywhere.

I am using VS2008

Answer 1

You definitely can embed a manifest in a .net dll. The contents of an application manifest do not all apply to an assembly, but some do. For example, the UAC entries don't make sense for a component manifest, but assemblyIdentity does.

Using the MT.EXE tool, you can embed a manifest into a dll:

Embed:

mt.exe -manifest filename.dll.manifest -outputresource:filename.dll;#2

Extract:

mt.exe -inputresource:filename.dll;#2 -out:filename.dll.extracted.manifest

Here are more links on related info:

Another dll embed example: http://msdn.microsoft.com/en-us/library/ms235591(v=VS.100).aspx

A SxS walkthrough: http://msdn.microsoft.com/en-us/library/ms973915.aspx

Answer 2

In most applications, a manifest is typically applied to EXEs/host apps - as this is the level at which one understands how all the dependent assemblies and their capabilities mesh together.

For example, in the case of setting the UAC marker via the trustinfo/security/requestedPrivileges/requestedExecutionLevel element, the case of a dependent assembly legitimately being able to say "I say we all understand about UAC" doesn't make sense.

Answer 3

The only thing that prevents you adding a manifest to a NET dll is the Visual Studio IDE. It can be circumvented very easily by modifying the .csproj directly - add the ApplicationManifest property in an appropriate property group. Add a manifest to an exe project and examine the .csproj for details.

Much easier than using MT.exe, which will replace the existing manifest (which you usually don't want to happen).