Lnk1120 1 unresolved externals c windows h

This forum has migrated to Microsoft Q&A. Visit Microsoft Q&A to post new questions.

Answered by:

Question

I am migrating my application from vc++6.0 to vc++2013

I am facing this following error

This error is pointing to parsed.dll file, and when i checked for its availability it was not found there.

Can you suggest what will be the solution for this

Answers

It should go in the main folder of your project.

Then in the sybesql.cpp file, add the following line of code somewhere (at or near the top is the usual place):

Then try compiling again. You may need additional files from the link that Wyck suggested and if so each one would get its own additional #pragma comment. line.

Another way to set it is to go in to your project’s properties, and then in the linker properties add it to the link library dependencies. See: http://msdn.microsoft.com/en-us/library/024awkd1.aspx .

If you’re having trouble understanding a specific error, then copy and paste the text of that error here and we can help you figure it out.

Unresolved external means that your code compiled (so all symbols were known at compile time) but something requires external linkage and that thing was not found. Usually this comes from including a header without linking against the associated library.

In its simplest form, here’s an example

This program will compile because there is a prototype (a declaration) of the function foo, but its implementation is not given, so it is assumed to be external. If there were a .lib file that provided the implementation of foo, then you could specify that .lib as an additional library file and it would link fine. This happens if foo is expected to come from an external static library or an external dynamic link library (by way of an import library).

So in your case, something is unresolved at link time. You haven’t disclosed what symbol is unresolved, but it’s highly relevant.

You also haven’t mentioned anything about parsed.dll. But I can only assume that you are seeing an error of an unresolved external that you suspect comes from the implib for parsed.dll. If so, then to resolve that, you need to find the import library for parsed.lib and link it into your program by specifying it as an additional library file in your project settings, or with a #pragma comment lib directive.

If parsed.dll is something you built yourself, then you can add a project reference to it and include it in your solution and specify your project to automatically link the import library from parsed.

But I’m just guessing (in those last two paragraphs) so you should really post the specific error and then I can help you with the specifics without guessing.

If you can’t find the .cpp file then use the second method instead. Include it in your project’s link library dependencies. Here’s a fuller description of how to do that (make sure you back up your project or commit all changes to version control first so that you can restore it if anything goes wrong):

1. In Visual Studio, go to Solution Explorer (you can find it in the VIEW menu if it isn’t visible) and right click on your project. In the context menu that appears, choose «Properties».
2. In the project’s Property Pages, change the «Configuration» to «All Configurations» and the «Platform» to «All Platforms». If there is only one platform there won’t be an «All Platforms» option in which case you don’t need to change that setting.
3. Then under «Configuration Properties», expand «Linker» and left click on «Input».
4. You should now see various options, one of which is «Additional Dependencies».
5. If the text box next to «Additional Dependencies» says » » then to be safe you should go back and for «Configuration» instead of using «All Configurations» switch to one of the individual configurations (e.g. «Debug») and for «Platform» switch away from «All Platforms» to one of the individual platforms (e.g. «Win32») and repeat the following steps for each combination of configuration and platform one-by-one until you have configured all of them.
6. If you left click in the text box next to «Additional Dependencies», it should become a drop down menu. Left click on the arrow button that appeared on the right and choose «Edit. «.
7. A window called «Additional Dependencies» will appear. This is where you can specify the additional .lib files that your project depends on. The inherited values box just tells you the .lib files that are automatically included for you because they contain functionality that is commonly used. You don’t need to worry about them.
8. In the text box above inherited values is where you will be entering data. There may already be some values specified in there. If so leave them alone. Enter the path to the libcs.lib file on its own separate line. Any other .lib files you need to add should also go on their own separate line. If people besides you will need to compile this, use the Macros to specify whichever portion of the path is likely to be different on their computers.
9. When all .lib files have been entered, click the «OK» button to close the «Additional Dependencies» window. If you are changing the configuration and platform combinations one-by-one, click Apply if it is not grayed-out. Then switch to the next combination and return to step 6.
10. When you have finished (either because you could set everything at once or because you went through and set the correct values for each combination of platforms and configurations) you should click the «OK» button in the project’s Property Pages window to close it.

As far as which folder the .lib file should go in, if you include it using the link library dependencies method then you can put it in any folder you want just so long as you specify the correct path to it in step 8 above.

It’s usually a good idea to put it in the directory that your project is in or one of the subdirectories in there (but not one that is used for output from the compiler such as the «debug» directory since it might get overwritten or accidentally deleted if it is in one of those directories). That way you can use the Macros mentioned in step 8 to specify the first part of the path. Usually the $(ProjectDir) macro. If it was in your project directory, then in step 8 you would just add a line that looked like this:

Unresolved external symbol _main

main.obj : error LNK2019: unresolved external symbol
Класс Circle (круг). Класс хранит Декартовы координаты центра круга, а также значения точки, на.

Unresolved external symbol main referenced in function __tmainCRTStartup
Ребята, у меня в солюшене 2 проекта. Один — статическая библиотека, другой — GUI. При компиляции.

Unresolved external symbol, unresolved token
Всем привет. У меня тут такое дело: // learncpp.cpp : main project file. #include «stdafx.h».

unresolved external symbol
Доброе время собственно не понимаю почему компилатор ругается. Файлы : main.cpp #include.

Вот Вам пример простейшей программы:

Решение

Доброго времени суток . прошу помощи вот по такому вопросу . читаю книгу Юрия Щупака Win32 API . там есть пример программы hello, world . и вот компилятор выдаёт мне две ошибки

Error 1 error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup MSVCRTD.lib

Error 2 fatal error LNK1120: 1 unresolved externals C:\Users\STRELOK\Documents\Visual Studio 2008\Projects\Hello World 1\Debug\Hello World 1.exe

в свойствах ставлю мультибайт . среда 2008 года .

Используется Unicode-версия класса окна (WNDCLASSEX), а полю ws.lpszClassName присваиваешь ANSI строку . . . Еще есть некоторые ошибки. Так будет правильнее:

Решение

Доброго времени суток . прошу помощи вот по такому вопросу . читаю книгу Юрия Щупака Win32 API . там есть пример программы hello, world . и вот компилятор выдаёт мне две ошибки

Error 1 error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup MSVCRTD.lib

Error 2 fatal error LNK1120: 1 unresolved externals C:\Users\STRELOK\Documents\Visual Studio 2008\Projects\Hello World 1\Debug\Hello World 1.exe

в свойствах ставлю мультибайт . среда 2008 года .

Используется Unicode-версия класса окна (WNDCLASSEX), а полю ws.lpszClassName присваиваешь ANSI строку . . . Еще есть некоторые ошибки. Так будет правильнее:

По поводу char-строк.

Макрос _T() работает так: если проект использует ANSI строки, то он оставляет строки без изменений, а если проект использует UNICODE строки, то он преобразовывает ANSI строку в UNICODE.

По умолчанию в последних версиях VS стоит «Use Unicode Character Set». Если ты переключил на «Use Multi-Byte Character Set» (а ты переключил ), то никакого преобразования нет. По факту избыточный код.

Хм. почитал тему, но вопрос собственно аналогичный вопросу топикстартера.

Вообще ситуация какая-то странная, толи перегрев, толит ещё что в голове у меня не так:

в проекте Visual Studio 2010 прописан Project Properties->C\C++->General->Additional Include Directories = $(SolutionDir)list\, вот, в данном каталоге лежат файлики mylist.h & mylist.cpp, в них расписаны шаблоны классов для динамических списков моего проекта.

Добавляю в эти файлики в заголовочный, допустим, функцию int vvv();, в файл исходного кода int vvv() , в итоге получаю:

LNK1120: 1 unresolved externals and LNK2019: unresolved external symbol

I’ve been getting these two errors and I cant seem to find a solution that works.

LNK1120: 1 unresolved externals

Error 1 error LNK2019: unresolved external symbol «public: __thiscall Vector3D::Vector3D(class Vector3D const &)» (??0Vector3D@@QAE@ABV0@@Z) referenced in function «public: class Vector3D __thiscall Vertex::GetPosition(void)» (?GetPosition@Vertex@@QAE?AVVector3D@@XZ)

I think its to do with my Matrix operator and the constructor in my Vector 3d class Any help will be much appreciated as I am quite new to C++

3 Answers 3

It says that the linker cannot find an implementation of Vector3D(const Vector3D& rhs); . This constructor is declared in your vector class, but not defined.

Do you have an implementation of the constructor somewhere in a .cpp file, and is this file known to your compiler?

C/C++ compilation works like that: At first, you have a number of so called «compilation units» — normally, every .cpp -file is one such compilation unit. Your program consists of all these separate units linked together (the «linking» process, happens after compilation). Every function that is called somewhere has to be defined exactly once in some compilation unit, unless it is defined inline (like the other methods of your class). If a method is declared, but not defined, the compiler will not complain — only the linker will. Imagine the compilation units having «sockets» and «connectors» which fit to the corresponding «sockets» of other units. The compilation process just creates these units assuming a particular «socket» shape (as given by declarations), whereas the linker actually tries to connect each «socket» with it’s «connector». So you see how the compilation process may suceed, but the linking not.

Linker errors can be tricky to solve, especially if you’re not that experienced yet. There can be many causes for them:

• Missing implementation/definition
• Definition exists, but somehow is not compiled (because the file is not passed to the compiler etc.)
• Different versions of libraries etc.

Edit: Apart from that, you should pass the vector by const reference, and create newVector by invoking it’s constructor, instead of creating a default constructed object and then assigning. And the final construction in the return statement is not needed as well. Improved code:

Visual C fatal error LNK1120: 1 unresolved externals

Don’t know whats wrong, all help will be greatly appreciated. I’m thinking I am having a problem with a file source, but am not sure.

4 Answers 4

You need to look at the line above LNK1120 , the LNK2019 error tells you what is wrong.

Inside of your void display(class student) function you are calling a function named decimals that is not defined anywhere in your source code or in a library.

This problem appeared to me when I added .c file instead of .cpp so check the name of the files as well

Make sure the external variable able to access in your current file. For Testing easy way is declare same name local variable for testing your logic working not , later change try to access external variable.

LNK 2019 error is a linker error which generally means some object is not available to the linker. Try clean rebuilding the project and then try to execute it.

Not the answer you’re looking for? Browse other questions tagged c++ or ask your own question.

Related

Hot Network Questions

Subscribe to RSS

To subscribe to this RSS feed, copy and paste this URL into your RSS reader.

site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2021.4.16.39093

By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.