C# NetStandard library template that requires a C++ Native Library

C# NetStandard Library template that requires a C++ native library. Other C# libraries can use it as library reference or nuget reference with the same behavior.

Prerequisites

• Visual Studio 2017. C# IDE on Windows.
• Visual Studio for Mac C# IDE on MacOS.
• Monodevelop C# IDE on Linux.
• CMake. C++ cross-compile tool.

Goal

Create a C# NetStandard library that requires a C++ Native Library. It must copy the correct native library file by platform (Windows, Linux and Mac) and architecture (x86 or x64) when it is referenced by another C# library/exe. Furthermore, the C# NetStandard library must be prepared to provide a nuget package. So you can use it as reference library (development) or nuget library (release) and the behavior must be the same.

Projects

• NativeLib folder is a simple C++ library that export a Sum method.
• NativeLibWrapper folder with a C# netstandard wrapper (pinvoke).
• ConsoleApp_x86 x86 test that references NativeLibWrapper library.
• ConsoleApp_x64 x64 test that references NativeLibWrapper library.
• Nuget_x86 x86 test that references NativeLibWrapper nuget.
• Nuget_x64 x64 test that references NativeLibWrapper nuget.

C++ NativeLib

Simple C++ library that export a Sum function. This function receives two numbers and returns the sum of these numbers.

CMake

(in NativeLib folder)

mkdir Build_x86
mkdir Build_x64

cd Build_86
cmake ../
cmake --build .

cd ..
cd Build_64
cmake -A x64 ../
cmake --build .

Challenges

• Select correct native library platform (Windows, Linux or Mac) and architecture (x86 or x64).
• Copy native library file to final project.
• Provide a valid nuget package.

NativeLibWrapper anatomy

• binaries folder: Contains the native library compiled files to all platforms.
• NativeLibWrapper.targets: Target to copy correct native libraries to final project by platform. (Based on solution name).
• DllRegister.cs: Class that select the correct native library architecture (x86 or x64) in runtime (only on Windows).
• NativeLibWrapper.dll.config: DLLMap file that indicates to pinvoke methods how to select the correct native library file on mono platforms (only on Linux and Mac).
• NativeLibWrapper.cs: Class with pinvoke method to native library.

Nuget

• Open UsingNativeLib_Nuget.sln solution
• Right click the project NativeLibWrapper and select the Pack command to generate nupkg file (Visual Studio 2017)
• Add nupkg folder as a new local repository in Tool -> Options -> Nuget Package Manager -> Package Sources.

Roadmap

To add Android, iOS and UWP platforms.

Special Thanks

• jacano
• danielcaceresm