如何在Visual Studio中使用C ++ shlwapi库？

Question

I wanted to make a simple program for classifying files by their extensions, but when tried to compile got the error

Severity Code Description Project File Line Error LNK2019 unresolved external symbol __imp__PathFileExistsW@4 referenced in function "void __cdecl classifyFiles(void)" (?classifyFiles@@YAXXZ)

My code is where PathFileExists is called is this:

void classifyFiles() {
    for (int i = 0; i < files.max_size(); i++) {
        //if each folder doesn't exist, create folder
        LPCWSTR folderName = (L"\\" + extensions.at(i)).c_str();
        if (!PathFileExistsW(folderName)) {
            CreateDirectory(folderName, NULL);
        };
        LPCWSTR destination = (extensions.at(i) + files.at(i)).c_str();
        //move file
        MoveFile(files.at(i).c_str(), destination);
    }
}

I googled a little and it seems it is not enough with including the Shlwapi.h header and also need to link the library. But I can't find any answer about how to do it in Visual Studio.

Note: I am also having problem finding were are each menu and everything (this is my first time with Visual Studio), so please make it clear where to find what and if possible include screenshots.

References: https://msdn.microsoft.com/en-us/library/windows/desktop/bb773584(v=vs.85).aspx

Answer 1

Add shlwapi.lib to your dependency list:

Configuration Properties -> Linker -> Input -> Additional Dependencies

Answer 2

There are two things I did for the build to succeed: Add
#pragma comment(lib, "Shlwapi.lib")
after the includes. In my specific case changing the following line of code made a difference, for some reason, even if they are the same. Changing:

if (!PathFileExistsW(folderName))

To:

if (PathFileExistsW(folderName) == FALSE)

For some reason using the value of PathFileExists like the first outputted a linking error even if everything else was in order. The next day I tested it again and it worked both ways. Maybe it was my imagination and was making some mistake.

Answer 3

首先，您需要添加VC ++目录，然后需要设置链接器输入。