I walked through this tutorial and tried to recreate the example I get this error:
Error 1 error LNK2019: unresolved external symbol __imp__GetXyz#0 referenced in function _main app.obj app
If I download the source from the website and run the project in visual studio it works, but If I even copy the code from the original project in my own visual studio solution it still doesn't work. I guess it must be some project settings, I don't know. What do do?
You need to add the XyzLibrary.lib to your Linker settings within project settings.
You can also do it directly in code by using #pragma comment(lib,"xyzlibrary.lib") if you are using VisualStudio.
The reason why it works in the given sample without these 2 approaches is that in the solution file, the dependencies are set from XyzExe to XyzLib, and XyzProject has 'Link Library Dependencies' in Linker settings set to true. However, I am not too keen on this approach, as I don't like to store data important for building inside solution files (for larger projects, developer's solution files can differ from build system solution files)
Seems like you are missing some external library that needs to be linked in. Whatever provides the GetXyz function is missing.
Open the Solution that works, right click the project, Properties, Linker, Input, and check what their Additional Dependencies list up. You need to add the same to your own project.
Related
I'm trying to create a native HoloLens 2 C++ application with OpenXR. In the Microsoft OpenXR-MixedReality example I discovered the XrSceneLib_uwp project which has the configuration type set as static library (.lib) in the Visual Studio properties. Accordingly to that I tried to add it as a library in my solution which also has a Core Application (C++/WinRT) in it where I want to use the functions from XrSceneLib_uwp. In my thinking it makes sens because I can use the library for example to create a holographic title scene without much effort. The problem here is that when I build my solution I'm getting linker errors and I don't know how to fix them. I'm also relatively new to Visual Studio (22 in my case) and most likely I'm just doing someting wrong in the linking process.
Linker error when I try to build:
Error LNK2019 unresolved external symbol xrGetInstanceProcAddr referenced in function "public: __cdecl `anonymous namespace'::ImplementXrApp::ImplementXrApp(struct engine::XrAppConfiguration)" (??0ImplementXrApp#?A0x934f03db##QEAA#UXrAppConfiguration#engine###Z) CoreApp3 \repos\CoreApp3\CoreApp3\XrSceneLib_uwp.lib(XrApp.obj) 1
My solution explorer
Here is what I do:
I copy and paste the shared and openxr_preview folders from the OpenXR-MixedReality .zip file in my project folder.
Add XrSceneLib_uwp.vcxproj in /shared/XrSceneLib as an existing project to my solution.
Add the path to the copied shared and openxr_preview folders in Properties->Configuration Properties->C/C++->General->Additional Include Directories.
Add also the path to XrSceneLib_uwp.vcxproj in Additional Include Directories in my main project (CoreApp).
Add reference in CoreApp to XrSceneLib_uwp (Add->Reference->Projects).
After that everything works fine and I can even build the solution. But when I try to use the library I'm getting these linker errors. I don't understand why it works in the OpenXR-MixedReality examples but not when I try to implement it on an different project. What am I missing? I assume that XrSceneLib may not have been designed to be used externally in other projects but at the same time I think it should be possible somehow.
I also tried to add Additional Library Directories and the missing object files but either I have done something wrong or it just simply does not work.
I really appreciate any help.
I think the linker is failing to find the OpenXR Loader. The sample projects in the microsoft/OpenXR-MixedReality github repo link to the OpenXR Loader using the NuGet package manager. I get the same linker error if I purposely remove the NuGet package references from the sample projects.
You can either link to the OpenXR Loader using NuGet or you can build the OpenXR Loader youself. Take a look at the "Using OpenXR in an existing project" section on the microsoft site:
https://learn.microsoft.com/en-us/windows/mixed-reality/develop/native/openxr-getting-started#using-openxr-in-an-existing-project
I have problems building my code that is using static lib detours. I am trying to do an old basic CTF. For that I want to get into detours.
Whenever I try to build my .dll file I get an issue
LNK2019 unresolved external symbol _DetourTransactionBegin#0 referenced in function _DllMain#12
Now, I have built the detours library using 3 different version of the visual studio dev console.
I have tried firing 'vcvars32.bat' and then using nmake to build the library which was able to build it, but I get the above error during linking my .dll. I have also tried building it with 'vcvarsamd64_x86.bat' and then using nmake to build it which also was able to build the library, but I still get the same error as above during linking.
I have tried the usual stuff: the include folder for detours.h is added to C++/General/Additional Include Directories.
Under Linker/Additional Library Directories I added them as follows: "C:\temp\det_retry\lib.X64";"C:\temp\det_retry\lib.X86";%(AdditionalLibraryDirectories).
And also under Linker/Input/Additional Dependencies I have the following: detours.lib;%(AdditionalDependencies)
What am I missing here? This is a blocker for me for a couple of days and I am reiterating the same steps trying to figure out what's missing but I cannot see. I'd really appreciate the input.
I am sure I am using the newest version because I have downloaded (cloned) detours from the ms github page.
It appears your "Additional Library Directories" are setup incorrectly or contain invalid entries rather. They look like actual library file entries (i.e. pointing to some specific files) versus being only directories (e.g. "my/lib/path/for/my_project/"). Visual Studio's naming conventions are somewhat cryptic but they should be directory entries only. There should be an entry to whatever directory contains the detours.lib file (e.g. "MyProject/Libs/MSDetour" ... where MSDetour is a folder with the "detours.lib" in it) and then Visual Studio should find the library and link everything correctly.
As a side note, if you are using the Visual Studio developer console for building your project/solution you might want to look into CMake ... it is, in my opinion, significantly easier to work with (less "settings" digging) and maintain in the long-run.
I'm using Microsoft Visual Studio and an SDK to develop an app. The SDK includes the files listed above. I'm coding in C++. I'm not sure what I need to include to be able to use the SDK.
I did the things below and tried building a simple hello world app but I keep getting the error LNK2019: unresolved external symbol_WinMain#16 referenced in function __tmainCRTStartup
What I've Done:
1)Right Click-Properties-Linker-Additional Library Directories-Changed path to where I have the lib folder on my computer.
2)Same but added the Inc folder that came with the SDK to C/C++ Additional Include Directories.
By doing the above I assume I am linking the lib and .h files to the project that came with the SDK. The SDK also came with .dll files which I have done nothing with. You can use a few different languages with the SDK so I'm not sure what I need to use and not use.
However, the header files are not showing up under external dependencies.
I guess I should note that I have tried to run it a couple times before this and am not sure if that could be causing an issue building it.
Thanks.
The error you're seeing has nothing to do with header files or source code. The error is due to you not choosing the correct Visual Studio project.
If you are writing a console program, and you defined a main() function as the entry point, then you should be choosing a Win32 Console Application project from Visual Studio.
The error stems from the program looking for the WinMain function, and that function exists when you choose a Win32 Project. Usually these projects are for building GUI-based Win32 apps.
I have a project that includes files from a different project. I am getting linking errors...
"unresolved external symbol "public: _cdecl classA::classA(void"
(??()classA ##QEAA#XZ) referenced in function "class classA *_cdecl
functionB(char const*)" (?functionB##YAPEAVClassA##PEBD#Z)...
and other 125 errors of the same type (after the constructor, which is the error I just listed, every function from the class I use is mentioned in one of the link errors).
The path for including the files of the second project is included in my property sheet. That project, on its own, builds fine.
I have tried to add that project to my solution, and add it as a dependency. No help. I have tried to add the dll that it creates in the project - linker - input. No help.
In Configuration properties, the Runtime Library is set to /MTd.
I have even tried to add extern "C" in front of my include. No help.
I have tried to build them with Debug or Release, x64 or Win32. I prefer Release x64 but I'll take anything.
Could you please help me - tell me what am I doing wrong, or where to look to fix this problem ? Thank you very much.
When you build the project which yours depends on, it should produce both a lib and a dll. You need to link that lib with your project. See this thread for a screenshot of how to link the lib in your project.
I found out that my dependencies in the Link - Input were being removed by the fact that I didn't explicitly specify that I can have dependencies in the property sheet. After changing the property sheet, I finally was able to create a dll.
I have the following workspace images of my project
I would like to know what are the highlighted components in Workspace ?
I tried to find out more about it by trying to access its properties but nothing was available. So I deleted them .But know if I try to build my VeCAD_EXE project I get unresolved external symbol errors for the methods defined in CAD_DLL project.
I suppose it acted as some reference to my CAD_DLL project.
But I don't know how do I get those 2 components back again :(.
Any views of how can I achieve this is highly appreciated.
Those are the dependencies that should be built before building VECAD_EXE project. Probably these project produce .lib/.dll that must be linked with main project and because they are missing you receive linking error.
To change dependencies for project go to Project -> Dependencies... menu.