Qt: windows functions are unresolved external symb

Question

I'm trying to compile a simple helloworld-like non-Qt C++ application using te WinAPI in QtCreator. Here's the code:

#include <windows.h>

int main()
{
    HWND cons = GetConsoleWindow();
    SetWindowText(cons, L"I am the console window");
    MessageBox(cons, L"Hello world!", L"I am the MessageBox", MB_OK | MB_ICONERROR);
    return 0;
}

Looks very simple, but when I've tried to build it, the compilation fails with:

main.obj:-1: error: LNK2019: unresolved external symbol __imp__MessageBoxW@16 referenced in function _main
main.obj:-1: error: LNK2019: unresolved external symbol __imp__SetWindowTextW@8 referenced in function _main

I started to seek, and I found this, but it wasn't helping me at all, because when I had written this:

LIBS += -L"C:\\Program Files (x86)\\Microsoft SDKs\\Windows\\v7.0A\\Lib"

and even this:

LIBS += -L"C:\\Program Files (x86)\\Microsoft SDKs\\Windows\\v7.0A\\Lib\\shell32.lib"

in my .pro, these "symbols" still stand unresolved. I ran qmake after each change to the .pro-file contents. So, any ideas?

Answer 1

-L sets the search paths for DLLs, but it doesn't actually link anything. The actual linking is done via -l. Setting the search path for system libraries shouldn't be necessary, but you'll need to link against user32:

win32:LIBS += -luser32

Answer 2

Additional to Frank's answer (which helped me very much, thanks for that!) I would like to add that this is only required vor MSVC, MinGW doesn't seem to need that line. Which was for me the most confusing part, I first thought I had problems with the msvc toolchain.

My inclusion now looks like this to reflect this fact:

msvc: LIBS += -luser32