0

I'm using Visual Studio 6.0 for a VC++ project. There are about 38 projects included in the workspace. I need to use the functions present in one of the projects, say X project... in another project say Y.

One way to do is to add all the .cpp files and .h files present in project X to project Y. This works. But I'm looking for a solution where I can include all the files of the project X, in project Y without actually adding the files physically. Some kind of settings must be there which should help me do this. I tried including all the related DLL's and .lib files present in X to Y, and when I execute, I get the error: unresolved external symbol"public:virtual__ blah blah...

user741196
  • 49
  • 8

2 Answers2

0

When you want to use a function of project X in project Y than the project X must be a kind of library (static library or DLL). To do so, you have to

  • change the include search path of project Y so that it includes the directory where the header files of project X reside.

  • add the library X.lib to the linker "additional libaries" of project Y. If X is a DLL project th X.lib import library is added, if X is a LIB project, the project output is immediately the X.lib to be added to project Y.

The latter step can be done be defined "project depencies" in the workspace. But I recommend to do this with linker settings.

Added the .cpp files to the project Y is a bad idea. The project X is designed to compile its files.

Edit: If X is a DLL project then it must export the symbols that you want to use.

Community
  • 1
  • 1
harper
  • 13,345
  • 8
  • 56
  • 105
  • Hi, project X is dll project. So in the project Y Settings-Link-Input-Additional Library path: I entered X.lib, doesnt seem to work.It gives me unresolved external symbol error. However, if I add the .cpp file from X project, the error goes off. What mistake am I doing here ? – user741196 May 10 '11 at 05:47
  • If Y is a DLL project, the Y.lib will define the **exported** symbols. Therefore you need to **export** the symbols that you want to be accessible when the DLL is loaded. – harper May 10 '11 at 07:01
0

Add the path containing the header file that you want to use (x.h) into 

Project->Settings->C/C++->Category(Preprocessor)->Additional Include directories

Then add the path containing the .lib file for the project you want to use (x.lib) into 

Project->Settings->Linker->Category(Input)->Additional Library path

Finally, enter the name of the lib you want to use (x.lib) into 

Project->Settings->Linker->Category(General)->Object/library modules

Then just do 

#include <x.h>

at the top of your new file in project Y to use methods from x.h

StevieG
  • 8,639
  • 23
  • 31
  • For the class redefinition error - this means you're including the same header in more than one other file, this means that the compiler will have multiple copies. To get prevent this, you should use #define in the included header file to ensure its included only once. Something like #ifndef X_H# define X_H #endif – StevieG May 10 '11 at 09:27