I have one guide integrating software files to my program on c++. Steps are:
-Add /Resources/xxx-io/include/ directory to your project include directories settings
-Add /Resources/xxx-io/lib/ directory to your project library directories settings
-Include xxx.h in your software code
Link executables with xxx.lib
What dose the last one mean? I'm building simple win console program with visual studio 2015 c++ that communicates with software. I have linked the lib and includes and included header, but that last one is mystery.
To say simply, it means that you should go to Project properities -> Linker -> Input and add there library, to which you want your executable to link to.
If you want to learn what does it actually mean, read some articles on how .libs work. To say shortly, .lib library is compiled code, that is inserted into your program.
Related
I've been programming in Python for over a year now but am just learning C++ and am unfamiliar with how to go about using external libraries, CMake and github for that matter. I'm trying to use an external library called cpr - https://github.com/whoshuu/cpr. So far I've followed the instructions in the 'Usage' section of that link up to, but not including, the "add_subdirectory(cpr)" bit.
So far I've got the source code for cpr in the Visual Studio project folder of my C++ project. In the project properties I've then added into Include Directories (under VC++ Directories) "$(SolutionDir)site_libs\cpr\include" and I've added the same thing into Additional Include Directories (under C/C++ -> All Options). This means that the following code compiles just fine:
#include <cpr/cpr.h>
int main(int argc, char** argv) {
auto r =
cpr::Get(cpr::Url{"https://api.github.com/repos/whoshuu/cpr/contributors"},
cpr::Authentication{"user", "pass"},
cpr::Parameters{{"anon", "true"}, {"key", "value"}});
r.status_code; // 200
r.header["content-type"]; // application/json; charset=utf-8
r.text; // JSON text string
}
However this code isn't working when it comes to building, due to link errors. I'm pretty sure the thing I'm missing is the actual .lib file for it to find where these functions etc are defined (nothing for cpr is set in the Linker -> Input property). So I'm wondering - how do I create this .lib file / is that even the right thing to do / what is this "add_subdirectory(cpr)" and where/how do I run it... basically what do I do to make this whole thing work..?! I've tried compiling cpr with CMake but it throws a load of errors about 'CMakeLists.txt' not present in certain folders.
Apologies if I've used any incorrect terminology here, only been learning C++ for a couple of days now. Any help massively appreciated!
If the library does not come as a binary distribution (that is with the .lib already built) you are going to need to build it as a separate project from the code you want to use the library, that step will build the .lib file. If a .sln is included with the distribution use that otherwise you may well have to create your own (or add it as a project to an existing solution).
Once you have a .lib add the directory under the VC++ directories of the project settings and add the actual .lib file name under Linker->Input on the Additional Dependencies line.
To build the library if the distribution does not include the needed VS files you will need to create a project at minimum (it can be part of the solution for your program), right click on the solution node in solution explorer and select Add->New Project, from there select Visual C++->Windows Desktop and either Dynamic Link Library or Static Library as you desire.
Go to the Project menu and select Project Dependencies, change your program to depend on the new project, this will set build order so your program project builds after the library.
You may need to disable the use of pre-compiled headers, right click on the new project node select Properties, go to C/C++->precompiled headers and change Precompiled Headers->Precompiled Header to Not using precompiled headers.
Next add the header and source files to the project and attempt building.
If this succeeded you will have a .lib suitable for use in the additional dependencies of your program project as already described.
I am a beginner on C++ and trying to learn about including libraries, and I haven't found documentation about it.
What are the ways of including libraries to a C++ project (Visual Studio). How do I implement them and which is the best way?
I was trying to include the SQLite library to a project. I tried to:
Include the header file in the include folder of the Visual Studio installation folder. It did appear in the External dependencies of my project, so I can do #include <sqlite3.h> without problems, but I don't know where I should put the implementation (a C file) and how to link it (is it in the linker>Input>Additional dependencies?).
Is it necessary that in order to include a library the file should be a .lib? Because I can't find the .lib for SQLite 3, do I have to include it in the lib folder of my Visual Studio installation?
Note: I am interested on the management of including a library in general. The SQLite 3 part is only because I took it as an example in order to learn how to add them.
A library is added in two steps
Adding headers path to the project
Adding .lib reference
In the first step, you must specify in the project where library headers are header. Usually, the path is specified in the project properties -> C++ -> Additional include directories, and them including files with relative paths.
In the second step you must specify in properties->linker the path where libraries (.lib) are located and the name of the library. With this Visual Studio is able to link the project properly.
go to project add existing item you must then select from the browse screen the .lib file you wish to add. and BINGO it is there!
best wishes
david
I am developing software where I need to use the OpenCV libraries under NetBeans. Took 2 days to be able to run correctly a C++ Application with OpenCV.
In a C++ Application I needed to add C:/OpenCV245/build/include in project properties->Build->C++ compiler-> Include Directories and Headers. Also, Under the Linker properties-> Additional Library Directories I had to add the following directories
C:/OpenCV245/release/lib
C:/OpenCV245/build/x64/mingw/lib
and add the .dll files I specifically needed in the linker->libraries
Now when I try to create a C++ Qt application, I add the proper include directories and headers but I can't add the path to my "additional libraries"...
I tried building to see what errors would pop:
cannot find -lopencv_core245.dll
cannot find -lopencv_highgui245.dll
How do we add .dll.a files to a C++ Qt application under Netbeans?
Programming environment:
NetBeans 7.4
MinGW 3.2 Compiler c++ compiler, msys make command and qt5.1.1 qmake for Qmake Command
Qt5.1.1
OpenCV2.4.5
Windows 8 64 bit
It appears as if you are trying to link with the *.DLL files instead of *.LIB files. The right way to go is to:
In the linker->libraries settings link to the *.LIB files you need instead of the *.DLL files.
Compile your program so you get an *.EXE
Put the relevant *.DLL-files in the same folder as the *.EXE
The program is now runnable if you double-click its icon in the file browser.
It the program refuses to run from Netbeans but it works from the file browser, then that is because you need to tell Netbeans what the "current working directory" is when you launch the program in debug mode. This setting should be available in some settings dialog.
+Under Project Properties-> Build -> Qt go to Expert Custom Definitions add add the path to the appropriate .dll.a files with the LIBS +=
+Under Project Properties-> Build -> C++ Compiler in Include Directories and Headers add the appropriate path for the includes. ex: C:\OpenCV\build\include
+Under Project Properties-> Build -> Linker click on Libraries then Add Library File... ( NOT ADD LIBRARY) and add the appropriate .dll.a files that were included in the first point.
I am trying to open sdl2 in my project on Visual C++ 2012 but i keep getting this error:
error LNK1104: cannot open file 'SDL2.lib'
I added the additional libraries and include folder but no luck..
I added the link to the libraries through the linker but i get the same error..
what should i do?
I'm referencing VS 2010, but I've read before that some people have had errors when using the VC++ Directories in their project properties as opposed to the Linker->General->Additional Library Directories.
Unfortunately, there really isn't much more to do besides making sure the directories are linked properly. There really is only one answer to this question. It also may depend on the download of SDL you chose, are you donwloading the Development Library as opposed to the binary?
Watch this video https://www.youtube.com/watch?v=or1dAmUO8k0.
In summary, you want to add the path include folder here: (configuration properties> C/C++ > General> Additional Include Directories),
and add the path of the lib folder here: (configuration properties> Linker > General> Additional Library Directories)
and finally, link .lib file in: linker > input > Additional Dependencies.
It seems like you didn't add your library directory path in VC++ Directories/Library Directories.. You have to link your library directory path (Where you have save you libraries of SDL) in your program. After adding, it will definitely work
I would like to add for others experiencing this problem that its an easy mistake if you are using the Development Library to link to the lib folder. SDL needs you link to either the x86 or x64 folder in the lib folder.
If you run or compile your program before you make those required changes of SDL then you will get this error always.. so first add a c++ file then make those changes and then write something and try to run ..this time it will never give this error
It seems like VS can't find the lib files. There are two ways you can do this. One is to configure the appropriate directories in VS as TwinkleBearDev's article shows. Another is to put the libraries directly where VS would look for them, as my article shows. I don't know if the folders for VS2012 are the same though - might be slightly different.
I have been using libcurl in a C++ project.
I have added the libcurl Include and Library directory's to the VC++ Directories and added the .lib file to the Linkers Input Additional Dependencies.
Everything works fine but when I check in my code (TFS) and somebody gets it on another machine they cannot build etc due to not having libcurl installed on their machine or installed in different paths etc.
How do I add all the necessary files to my C++ Solution so that anyone getting the project from source control can build and link without error.
Thanks
The solution I went with was too add the library file to a folder within my solution, then add
$(SolutionDir)libs\curllib.lib
To the Additional Dependencies within Linker->Input
You can not add the library to the solution. you should distribute the library along the source code. Place it in a subdirectory of the project so that it goes along the whole project source. Then configure the path in Additional Library Dependencies. That way the people should be able to link appropriately when building from source.