How to copy OpenCV DLL files into cmake debug/release folder? - opencv

Question

I need to copy
C:\opencv-3.4.0.-opencl\bin\Debug\*.dll =>
myproj\build\bin\Debug\*.dll
and also
C:\opencv-3.4.0.-opencl\bin\Release\*.dll =>
myproj\build\bin\Release\*.dll
I'd like to do it in one command for Build/Release if possible.

Answer 1

You can copy files on a post-build command. A step through tutorial can be found here.
The basic concept is that you can use batch file commands, as a post-build step in Visual Studio to do basically anything you want as you build.
A further tutorial can be found here
For CMAKE
The easiest way is to follow the advice above but instead of putting it in the post-build options in VS just add a custom command

Answer 2

You can try using CPack to handle multiple configuration at one go. See an example in the following tutorial
https://cmake.org/cmake/help/latest/guide/tutorial/index.html#packaging-debug-and-release-step-12
By default, CMake’s model is that a build directory only contains a
single configuration, be it Debug, Release, MinSizeRel, or
RelWithDebInfo. It is possible, however, to setup CPack to bundle
multiple build directories and construct a package that contains
multiple configurations of the same project.
Then you will need to use either of the following method for each configuration to copy the files you need
configure_file
https://cmake.org/cmake/help/latest/command/configure_file.html
or
add_custom_command
https://cmake.org/cmake/help/latest/command/add_custom_command.html
Here is an example from reddit
https://www.reddit.com/r/cmake/comments/gmewhu/copy_one_file_in_src_directory_to_build_directory/
# Copy <filename> to build directory
set(copy_source_dir "${CMAKE_SOURCE_DIR}/src/<path>")
set(copy_dest_dir "${CMAKE_BINARY_DIR}/Build/<path>/$<CONFIG>")
set(copy_file_name "<filename>")
add_custom_command(
TARGET ${PROJECT_NAME} POST_BUILD
COMMAND ${CMAKE_COMMAND} -E make_directory ${copy_dest_dir}
)
add_custom_command(
TARGET ${PROJECT_NAME} POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy "${copy_source_dir}/${copy_file_name}" "${copy_dest_dir}/${copy_file_name}"
COMMENT "Copying ${copy_file_name} to build directory"
)