Use 64-bit Native .DLL in C# Unit Test

Question

I have a 64 bit native library built from a vcxproj file auto generated by CMake. Part of the CMake build scripts auto generates Swig files in csharp. I build the .cs files generated by Swig using the .csproj labeled Articaft 1 below. I then have a C# Unit Test project Artifact 2 below which references the .dll generated from Articaft 1 . Articafct 2 also copies the dll produced by the 64 bit native library build.

If I compile the native library as a 32 bit library everything works okay, but if I go to use the 64 bit native library in the C# Unit Test project, the test fails with:

C:\Users\mehoggan\Devel\QuadKeys\UnitTestCSharp\TestBingSystem.cs:line 13
Result Message: 
Test method QuadKeyTests.TestBingSystem.TestCtor threw exception: 
System.TypeInitializationException: The type initializer for 'QuadKeyNS.SwigQuadKeyPINVOKE' threw an exception. ---> System.TypeInitializationException: The type initializer for 'SWIGExceptionHelper' threw an exception. ---> System.BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)

How do I get my C# unit tests to use the 64 bit version of the library?

---

Artifact 1

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
    <PropertyGroup>
        <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
        <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
        <ProjectGuid>f7fe6699-ce1d-443b-b6e9-05eb4e135ac6</ProjectGuid>
        <OutputType>Library</OutputType>
        <AppDesignerFolder>Properties</AppDesignerFolder>
        <RootNamespace>QuadKeyCSharp</RootNamespace>
        <AssemblyName>QuadKeyCSharp</AssemblyName>
        <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
        <FileAlignment>512</FileAlignment>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
        <DebugSymbols>true</DebugSymbols>
        <DebugType>full</DebugType>
        <Optimize>false</Optimize>
        <OutputPath>bin\Debug\</OutputPath>
        <DefineConstants>DEBUG;TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
        <DebugType>pdbonly</DebugType>
        <Optimize>true</Optimize>
        <OutputPath>bin\Release\</OutputPath>
        <DefineConstants>TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
    </PropertyGroup>
    <ItemGroup>
        <Reference Include="System"/>
        <Reference Include="System.Core"/>
        <Reference Include="System.Xml.Linq"/>
        <Reference Include="System.Data.DataSetExtensions"/>
        <Reference Include="Microsoft.CSharp"/>
        <Reference Include="System.Data"/>
        <Reference Include="System.Net.Http"/>
        <Reference Include="System.Xml"/>
    </ItemGroup>
    <ItemGroup>
        <Compile Include=".\csharp\*.cs" />
        <Compile Include="AssemblyInfo.cs" />
    </ItemGroup>
    <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

---

Artifact 2

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
        <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
        <ProjectGuid>{1306B89A-7ED0-4A90-B7A2-6A39ABD9016C}</ProjectGuid>
        <OutputType>Library</OutputType>
        <AppDesignerFolder>Properties</AppDesignerFolder>
        <RootNamespace>UnitTestCSharp</RootNamespace>
        <AssemblyName>UnitTestCSharp</AssemblyName>
        <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
        <FileAlignment>512</FileAlignment>
        <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
        <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">10.0</VisualStudioVersion>
        <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
        <ReferencePath>$(ProgramFiles)\Common Files\microsoft shared\VSTT\$(VisualStudioVersion)\UITestExtensionPackages</ReferencePath>
        <IsCodedUITest>False</IsCodedUITest>
        <TestProjectType>UnitTest</TestProjectType>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
        <DebugSymbols>true</DebugSymbols>
        <DebugType>full</DebugType>
        <Optimize>false</Optimize>
        <OutputPath>bin\Debug\</OutputPath>
        <DefineConstants>DEBUG;TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
        <DebugType>pdbonly</DebugType>
        <Optimize>true</Optimize>
        <OutputPath>bin\Release\</OutputPath>
        <DefineConstants>TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
    </PropertyGroup>
    <ItemGroup>
        <Reference Include="QuadKeyCSharp">
            <HintPath>..\Swig\bin\$(Configuration)\QuadKeyCSharp.dll</HintPath>
        </Reference>
    <Reference Include="System" />
    </ItemGroup>
    <Choose>
        <When Condition="('$(VisualStudioVersion)' == '10.0' or '$(VisualStudioVersion)' == '') and '$(TargetFrameworkVersion)' == 'v3.5'">
            <ItemGroup>
                <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
            </ItemGroup>
        </When>
        <Otherwise>
            <ItemGroup>
                <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework" />
            </ItemGroup>
        </Otherwise>
    </Choose>
    <ItemGroup>
        <Compile Include="*.cs" />
    </ItemGroup>
    <ItemGroup>
        <Content Include="SwigQuadKey.dll" />
    </ItemGroup>
    <Choose>
        <When Condition="'$(VisualStudioVersion)' == '10.0' And '$(IsCodedUITest)' == 'True'">
            <ItemGroup>
                <Reference Include="Microsoft.VisualStudio.QualityTools.CodedUITestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
                    <Private>False</Private>
                </Reference>
                <Reference Include="Microsoft.VisualStudio.TestTools.UITest.Common, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
                    <Private>False</Private>
                </Reference>
                <Reference Include="Microsoft.VisualStudio.TestTools.UITest.Extension, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
                    <Private>False</Private>
                </Reference>
                <Reference Include="Microsoft.VisualStudio.TestTools.UITesting, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
                    <Private>False</Private>
                </Reference>
            </ItemGroup>
        </When>
    </Choose>
    <Import Project="$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets" Condition="Exists('$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets')" />
    <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
    <PropertyGroup>
        <PostBuildEvent>copy "$(ProjectDir)..\build\QuadKey\$(Configuration)\QuadKey.dll" "$(ProjectDir)bin\$(Configuration)\SwigQuadKey.dll" /Y</PostBuildEvent>
    </PropertyGroup>
</Project>

Answer 1

You are running VSTest as a 32-bit process. In the Test menu of Visual Studio, you will find a setting that tells VSTest to run as a 32- or 64-bit process. Just change it to 64-bit and leave your unit test assembly as AnyCPU.

Answer 2

You'll have to specify that the C# project should only run as a 64 bit program. Change the "AnyCPU" target to "x64" (I think; I'm going off of memory). This will then tell the managed compiler to generate 64 bit code instead of 32 bit.