How do I use ILMerge with .NET 4.5 in AfterBuild?

Question

We want to upgrade our solution with several projects to .NET 4.5. We already use Visual Studio 2012. We use ILMerge to merge the assemblies to a single EXE.

Our current .csproj file for the main project look like this:

<Target Name="AfterBuild" Condition=" '$(Configuration)' == 'Release' ">
    <CreateItem Include="@(ReferenceCopyLocalPaths)" Condition="'%(Extension)'=='.dll'">
        <Output ItemName="AssembliesToMerge" TaskParameter="Include" />
    </CreateItem>
    <PropertyGroup>
        <ReferenceAssemblies>C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0</ReferenceAssemblies>
    </PropertyGroup>
    <Message Importance="high" Text="Executing ILMerge...with target platform from $(ReferenceAssemblies)" />
    <Exec Command="&quot;$(SolutionDir)LIB\ILMerge.exe&quot; /out:@(MainAssembly) /internalize /targetplatform:v4,&quot;$(ReferenceAssemblies)&quot; &quot;@(IntermediateAssembly)&quot; @(AssembliesToMerge->'&quot;%(FullPath)&quot;', ' ')" />
    <Delete Files="@(ReferenceCopyLocalPaths->'$(OutDir)%(DestinationSubDirectory)%(Filename)%(Extension)')" />
</Target>

How should this look for .NET 4.5?

I've read here that there are some issues using ILMerge with .NET 4.5.

Answer 1

I can't find any good documentation on this, but as suggested by Matt Wrocks blog post and another question about ILMerge, I first tried to use the same Reference Assemblies path as for .NET 4.

This seemed to work at first, before re-targeting our NuGet packages to .NET 4.5. (Specifically Microsoft.AspNet.WebApi.Client which adds a reference to the new .NET 4.5 assembly System.Net.Http.WebRequest which before was included in the NuGet package.)

After updating reference assemblies path to .NET 4.5 it worked:

C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.5

<Target Name="AfterBuild" Condition=" '$(Configuration)' == 'Release' ">
    <CreateItem Include="@(ReferenceCopyLocalPaths)" Condition="'%(Extension)'=='.dll'">
        <Output ItemName="AssembliesToMerge" TaskParameter="Include" />
    </CreateItem>
    <PropertyGroup>
        <ReferenceAssemblies>C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5</ReferenceAssemblies>
    </PropertyGroup>
    <Message Importance="high" Text="Executing ILMerge...with target platform from $(ReferenceAssemblies)" />
    <Exec Command="&quot;$(SolutionDir)LIB\ILMerge.exe&quot; /out:@(MainAssembly) /internalize /targetplatform:v4,&quot;$(ReferenceAssemblies)&quot; &quot;@(IntermediateAssembly)&quot; @(AssembliesToMerge->'&quot;%(FullPath)&quot;', ' ')" />
    <Delete Files="@(ReferenceCopyLocalPaths->'$(OutDir)%(DestinationSubDirectory)%(Filename)%(Extension)')" />
</Target>

In most cases a path to .NET 4 assemblies would also work, but when referencing new assemblies in .NET 4.5, the path need to be updated.

Note that in the example ILMerge.exe is downloaded to a folder in the solution directory called LIB.