Add Windows CMake instructions

[fedorovmichael]

Hi,
I try to run the example as is and after running cmake command running the command make and getting error:
make: *** No targets specified and no makefile found

[domesticmouse]

By default, cmake on Windows generates a VSCode solution file. You should be able to pass cmake the appropriate flags to generate an appropriate Makefile, but I'm not a CMake expert.

[fedorovmichael]

but it from your example:
https://github.com/dart-lang/samples/tree/master/ffi

Readme:
Building native libraries
Each sample uses CMake to generate a Makefile. To build the native library for each sample:

cd hello_world/hello_library
cmake .
make
The make command creates a libhello.dylib (macOS), libhello.dll (Windows) or libhello.so (Linux) library file.

[MrUnfunny]

@domesticmouse By passing <-G "Unix Makefiles"> flag with cmake command, we can generate appropriate makefiles for "make" command, but using it in this way, the path of generated dynamic library will be "..\hello_library\libhello.dll" instead of "..\hello_library\Debug\hello.dll" as expected by the code. So, either we can change path in code or use visual studio to build sln file. However, the documentation for windows must be update in either case.

[function1983]

Running make in windows is not so trivial as in Linux. Here are the steps:

• Run cmake .. This will create a visual studio project structure.
• Double click on hello_library.vcxproj to open with visual studio (you should have visual studio installed, community version works just fine)
• Default build option is debug, change it to release
• Click Build or press F7

You should find 4 files including hello.dll in a newly created Release folder.

[victorruandev]

Hello! I'm trying to do what the READ.ME explains but it is not working. Somebody can help-me? I just copy the project called "Hello World", my code is exactly the same.

[domesticmouse]

Also this one @cbracken.