I am going to write Qt3D application in windows.
I have also installed necessary tools , but after compilation i receive 'unresolved external symbol' error. what is the solution?
Note : my compiler is microsoft visual c++ 9.0
Are you linking-in the Qt3D library? If you don't - that's the reason for your issue. Open your project and add the neccessary .lib file into the list of libraries (and don't forget to either use a full, preferably relative, path or to add additional library path to the project's library path list)
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I'm using several libraries built through vcpkg (such as civet-web and prometheus-cpp), against my Visual C++ projects. When building x86 all is perfect, in x64 I get a bunch of linker errors:
error LNK2001: unresolved external symbol __CxxFrameHandler4
Searching online all references to this symbol/error are about specific projects, I cannot find what __CxxFrameHandler4 is and what problem this error is highlighting. I don't know if it's a problem with the way vcpkg is building the library, or a problem in my project or how to start looking for a solution.
I did find this blog article but it is in reference to a preview of VS2019, I cannot find any settings related to it: https://devblogs.microsoft.com/cppblog/making-cpp-exception-handling-smaller-x64/
If anyone can explain what this is all about it would be a big help.
I faced the same issues when trying to install and use cpr with vcpkg. I wanted to use cpr library in a VS2015 project.
Reason: I had VS2019 installed. vcpkg uses latest version of toolset Visual Studio.
Resolution: Add your own triplet or change existing such a way that your specified toolset is used. Adding did not work in my case so I changed existing "triplet" files in triplet folder in vcpkg. I wanted vcpkg to use toolset that comes with VS2015 (It's V140)
Content of x86-windows.cmake file
set(VCPKG_TARGET_ARCHITECTURE x86)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)
set(VCPKG_PLATFORM_TOOLSET "v140")
set(VCPKG_DEP_INFO_OVERRIDE_VARS "v140")
Content of x64-windows.cmake file
set(VCPKG_TARGET_ARCHITECTURE x64)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)
set(VCPKG_PLATFORM_TOOLSET "v140")
set(VCPKG_DEP_INFO_OVERRIDE_VARS "v140")
A more general answer is that this happens if you are mixing objects that were built with different platform toolsets, e.g.,
Visual C++ 2015 (v140)
Visual C++ 2017 (v141)
Typically, you (or someone else) may have built a dependency of your project with a different compiler version (platform toolset), and the fix it to change the platform toolset of either your project or the dependency (or use the correct build of the dependency, if you used a pre-built package)
I think you pointed out the right article which is
https://devblogs.microsoft.com/cppblog/making-cpp-exception-handling-smaller-x64/
I faced a similar issue in linking 64-bit library built with VC143 toolset with a 64-bit Application built with VC141 toolset.
After adding the following properties to VC143 built static library project, I was able to build the application. This disables the new feature mentioned in the above article (Exception Handling Smaller)
VS2019->Properties->C/C++->Command Line add '-d2FH4-'
VS2019->Properties->Linker->Command Line add '-d2:-FH4-'
I am using visual studio 2010 under Win7-64bit to build an application with openCV. I finished development and build the release version without error. I also successfully run the program in debug mode. I then move the .exe file to other directory in the same computer. I run it in cmd.exe and I got error warning: Error opening file <../../modules/highgui/src/cap_ffmpeg_implhpp:537>
I guess there are some dependence with some libraries of openCV but I don't how to solve it. My final task is that I can use that .exe in another computer under Win7 directly. How to do it?
I found a similar question here. But I don't have .dll file built, so what should I do to solve this problem?
Building an OpenCV app with shared libs (DLLs) require the DLLs to be available (same folder or in lookup path) to the exe when it is run.
If you are using static linking then you don't need any of the OpenCV DLLs to be reachable. However, due to licensing issues, ffmpeg is linked dynamically even when the rest of the libs are linked statically, and thus, you need to have the ffmpeg DLL available for the exe. It is called something like opencv_ffmpeg*.dll.
Note that this is only needed if you are using highgui related functionality.
I dont have visual studio 2008 installed.I am using 2012 and i rebuild this projects by cleaning.I checked the project settings and controlled the additional libraries and unfortunately I couldnt find any lib link has this name...in project just .h files of date_time are used but no lib linking. I configured new version of boost but STILL it wants this lib ? so is there any way I can solve this problem ?
With Visual Studio, boost use an auto linking system.
Special code in Boost header files detects your compiler options and
uses that information to encode the name of the correct library into
your object files; the linker selects the library with that name from
the directories you've told it to search.
date_time is one of boost modules that need a library (which is not header only).
So, you have to build them, using bjam (and --toolset=msvc-9.0), or retrieve them already built for your system.
Other option: disable auto linking. Just define
BOOST_DATE_TIME_NO_LIB
And link manually.
I am trying to use the DevIl image library in Windows in my project, using MSVS2010. I have downloaded the sdk "DevIL 1.7.8 SDK for 32-bit Windows" from http://openil.sourceforge.net/download.php and put in a folder where all my others libraries are. I have configured my project to include its headers and to link with the .lib provided. I have copied the dll provided to the folder my .exe is. It compiles and links with no problem but when i try to execute it i have an error popup saying something like "procedure entry point _ilGetData#0 could not be located in DevIl.dll" (translation from spanish). I have followed the same steps as in all libraries i am using with no problems, so i don´t know where the problem is.
Thanks for you help.
I believe the problem is that the binaries were built with an older version of Visual Studio... you may have to build the library yourself.
Can someone link me a good guide for using libraries in a c or c++ project?
Right now I'm trying to add OpenCV to a newly created project. I've added all the directories I can think of in "Project and Solutions -> VC++ Directories" and to make sure I've dragged and dropped all the .lib and .dll files into the project.
The project builds but when I run the simple "Hello, World program" it gives me this error message:
"cv.exe unable to locate component.
This application has failed to start because cv200.dll was not found. Re-installing the application may fix this problem."
How can I really add this cv200.dll? I've dragged&dropped it into the project..
Thanks!
You need to make sure that cv200.dll is in the DLL search path at run time. The easiest way to do this is to put it in the same directory as the built executable. Dragging and dropping a DLL or LIB file into your project has no effect.
MSDN has a good description of the full DLL search order when loading libraries at runtime.
By default during installation OpenCV create env. variable path \bin.
All dll assumed to be in that dir. However you are using OpenCV 2.0, and OpenCV 2.0 installation doesn't include lib and dll files for Visual Studio. You seems already built all dll's and lib's. If you installed OpenCV correctly just move all dll's into \bin (for example C:\Program Files\OpenCV\bin)
If for some reason you are missing some dll or libs here is instruction how to build them
http://mirror2image.wordpress.com/2009/10/20/switching-to-opencv-2-0-with-vs2005/