How to make Visual Studio copy a DLL file to the output directory?
Use a post-build action in your project, and add the commands to copy the offending DLL. The post-build action are written as a batch script.
The output directory can be referenced as $(OutDir). The project directory is available as $(ProjDir). Try to use relative pathes where applicable, so that you can copy or move your project folder without breaking the post-build action.
$(OutDir) turned out to be a relative path in VS2013, so I had to combine it with $(ProjectDir) to achieve the desired effect:
xcopy /y /d "$(ProjectDir)External\*.dll" "$(ProjectDir)$(OutDir)"
BTW, you can easily debug the scripts by adding 'echo ' at the beginning and observe the expanded text in the build output window.
The details in the comments section above did not work for me (VS 2013) when trying to copy the output dll from one C++ project to the release and debug folder of another C# project within the same solution.
I had to add the following post build-action (right click on the project that has a .dll output) then properties -> configuration properties -> build events -> post-build event -> command line
now I added these two lines to copy the output dll into the two folders:
xcopy /y $(TargetPath) $(SolutionDir)aeiscontroller\bin\Release
xcopy /y $(TargetPath) $(SolutionDir)aeiscontroller\bin\Debug
(This answer only applies to C# not C++, sorry I misread the original question)
I've got through DLL hell like this before. My final solution was to store the unmanaged DLLs in the managed DLL as binary resources, and extract them to a temporary folder when the program launches and delete them when it gets disposed.
This should be part of the .NET or pinvoke infrastructure, since it is so useful.... It makes your managed DLL easy to manage, both using Xcopy or as a Project reference in a bigger Visual Studio solution. Once you do this, you don't have to worry about post-build events.
UPDATE:
I posted code here in another answer https://stackoverflow.com/a/11038376/364818