How to conditionally reference a DLL based on a compilation symbol?

Question

Visual Studio 2013.

I have an external DLL which I am referencing like this in the csproj file:

Answer 1

The conditional compilation symbols are in the DefineConstants MSBuild property. Check that this contains your symbol:

<Reference Include="NameOfDll" Condition="$(DefineConstants.Contains('Fred'))">
  <HintPath>Path\To\Dll\NameOfDll.dll</HintPath>
</Reference>

Pick a distinctive name for the symbol. Not something that could be a substring of another constant like Debug or Trace.