SHGetKnownFolderPath was not declared in this scope

Question

I've been studying Java-programming for about 7 months now and I've become interested in c++. I'm currently reading a c++ book too.

I'm using eclipse c++ since I'm pretty familiar with eclipse.

I have made like 6 projects (small ones) in c++ and everything has worked fine until now.

My problem is that I can not get the SHGetKnownFolderPath method to work. The complete line is red , eventhough I have imported everything, build it, tried to run it. I have checked on internet sites and I've used the same code as other people has, but still not working for me.

It says: Function SHGetKnownFolderPath could not be resolved

I'm on a windows 8 computer 64 bit. Here is the code: UPDATE

    #define WINVER 0x0600 // 0x06020000  0x06030000
#include <shlobj.h>
#include <windows.h>
#include <combaseapi.h>
#include <comutil.h> //for _bstr_t (used in the string conversion)
#include <knownfolders.h>
#include <winerror.h> //for HRESULT
#include <winnt.h>
#include <iostream>
#include <string>






using namespace std;

int main(){

    LPWSTR wszPath = NULL;
    HRESULT hr;

    hr = SHGetKnownFolderPath(FOLDERID_Documents, 0, NULL, &wszPath);// THIS LINE IS COMPLETELY RED

    if (SUCCEEDED(hr)){
    _bstr_t bstrPath(wszPath);
    std::string strPath((char*)bstrPath);
    std::cout << strPath;
    }

    CoTaskMemFree(wszPath);

return 0;
}

Here is the log:

     #pragma comment(lib, "comsuppw")
 ^
..\src\HelloWorld.cpp: In function 'int main()':
..\src\HelloWorld.cpp:21:64: error: 'SHGetKnownFolderPath' was not declared in this scope
 hr = SHGetKnownFolderPath(FOLDERID_Documents, 0, NULL, &wszPath);

There is a little arrow pointing at the last parenthesis under &wszPath)

What could possibly be wrong? I will be grateful for all answers or hints that I could get.

Answer 1

Nothing wrong with Eclipse, it is correctly processing the error output from the compiler.

Nothing wrong with the compiler, it is correctly complaining about an attempt to use a function without a preceding declaration.

The official documentation clearly tells you where to get that declaration:

Since this function requires Vista or later, you'll also need to follow the instructions at Using the Windows Headers for setting compatibility with a particular Windows version.

#define WINVER 0x0600
#include <windows.h>
#include <shlobj.h>

Once you fix your includes (not imports! C++ is not Java.) you'll then discover that having the ability to cast does not make type safety issues go away. This code is horribly broken:

_bstr_t bstrPath(wszPath);
std::string strPath((char*)bstrPath);

Casting a UTF-16 string to char* does not get you an ASCII string. You can either use wcout which understands UTF-16, or call WideCharToMultiByte to get an ASCII string that cout can accept.

Answer 2

The problem is you're using WINVER, when you should be using _WIN32_WINNT. WINVER mainly only affects very old features -- you'll generally want to define them both.

#define WINVER 0x0600
#define _WIN32_WINNT 0x0600