cpp-lib-and-dll-on-visual-studio (2/2)

cpp-lib-and-dll-on-visual-studio (2/2)

• previous post covers
  • what LIB and DLL files are
  • how to make LIB files
  • how to use LIB files
• this post covers
  • how to make DLL files
  • how to use DLL files
  • difference between LIB and DLL
• environment
  • Windows 10 / Home
  • Visual Studio 2017 / Community

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make-dll

• open Visual Studio and make an empty solution

• add a new project by selecting Windows Desktop Wizard

• select Dynamic Link Library (.dll) in Application type: combo box
• uncheck Precompiled Header radio button

• you will get the screen like this

• make a header file and fill with the code above

• the macro determines whether the program will export DLL or import DLL

• fill the rest of the header

• make a source file and fill with the code above

• build solution and check the generated LIB and DLL files in output directory

use-dll

• open or make any project easy to include the library
• I recommend you to make Empty Project for convenience

• prepare any c/cpp file in the project

• you should add the LIB project path into Additional Include Directories in project property window
  • the path will be used for including header files
• in my case, the path is D:\Code\VS2017\practice-dll\MathLibrary

• now you can include the header file

• you should add the LIB output path into Additional Library Directories in project property window
  • the path will be used for setting range of including LIB file
• in my case, the path is D:\Code\VS2017\practice-dll\Debug

• you should add the LIB file name into Additional Dependencies in project property window
  • the name will be used for including certain LIB file
• in my case, the name is MathLibrary.lib

• write the code above and build the solution

• check the generated executable file in output directory

• copy the DLL file into where the executable file is

• debug or run the program and you can see the result

wrap-up

• references are here

  • for LIB
    • https://docs.microsoft.com/en-us/cpp/windows/walkthrough-creating-and-using-a-static-library-cpp?view=vs-2017
  • for DLL
    • https://docs.microsoft.com/ko-kr/cpp/build/walkthrough-creating-and-using-a-dynamic-link-library-cpp?view=vs-2017

• in using LIB

  • the program using library includes LIB file before executing itself
    • this is why LIB method wastes the memory
  • need for 3 main settings
    • header file path
    • LIB file path
    • LIB file name
  • structure
    • $Executable(Program → Header → .lib)$
    • LIB file contains implementation
    • the program using LIB can run by itself

• in using DLL

  • the program using library includes DLL file after executing itself
    • this can help the program get lighter
  • need for 4 main settings
    • 3 main settings for LIB method
    • locating DLL file into the same path with the executable file
  • structure
    • $Executable(Program → Header → .lib) → .dll$
    • LIB file just indicates DLL file and DLL file contains implementation
    • the program using DLL cannot run by itself