Link Error 2001 when linking to User32.dll

I'm trying to link an object file that uses two methods declared in winuser.h and defined in User32.dll: GetMonitorInfo and WindowFromMonitor. The source compiles to an object file just fine, but when I try to link, I get the following error output:

D3dCtx.obj : error LNK2001: unresolved external symbol xGetMonitorInfo
D3dCtx.obj : error LNK2001: unresolved external symbol xMonitorFromWindow

The thing is, I don't call "xGetMonitorInfo" or "xMonitorFromWindow". Running grep on all source files shows that only "GetMonitorInfo" and "WindowFromMonitor" are being called. I'm properly including windows.h, which includes winuser.h. I'm also properly setting my LIBPATH in the linker options, which is confirmed by verbose link output.

The following also appears in my verbose link output:

Found __imp_GetMonitorInfoA
    Referenced in nafxcw.lib(afxribboncategory.obj)
    Referenced in nafxcw.lib(afxtooltipctrl.obj)
    Referenced in nafxcw.lib(afxribbonkeytip.obj)
    Referenced in nafxcw.lib(afxfullscreenimpl.obj)
    Referenced in nafxcw.lib(afxframeimpl.obj)
    Referenced in nafxcw.lib(afxglobalutils.obj)
    Referenced in nafxcw.lib(afxdropdowntoolbar.obj)
    Referenced in nafxcw.lib(wincore.obj)
    Referenced in nafxcw.lib(afxglobals.obj)
    Referenced in nafxcw.lib(afxpopupmenu.obj)
    Referenced in nafxcw.lib(afxpropertygridtooltipctrl.obj)
    Loaded User32.lib(USER32.dll)
Found __imp_MonitorFromWindow
    Referenced in nafxcw.lib(wincore.obj)
    Loaded User32.lib(USER32.dll)

Furthermore, GetMonitorInfo is defined in winuser.h as:

WINUSERAPI
BOOL
WINAPI
GetMonitorInfoA(
    __in HMONITOR hMonitor,
    __inout LP开发者_Python百科MONITORINFO lpmi);
WINUSERAPI
BOOL
WINAPI
GetMonitorInfoW(
    __in HMONITOR hMonitor,
    __inout LPMONITORINFO lpmi);
#ifdef UNICODE
#define GetMonitorInfo  GetMonitorInfoW
#else
#define GetMonitorInfo  GetMonitorInfoA
#endif // !UNICODE

When I change all reference to "GetMonitorInfo" to "GetMonitorInfoA", I only get

D3dCtx.obj : error LNK2001: unresolved external symbol xMonitorFromWindow

as my linker error output. Unfortunately, MonitorFromWindow doesn't seem to have multiple versions available.

I should note that I am using the 64bit versions of the libraries, link, and cl.

What's going on here, and how can I successfully link my program?

I don't know whether you were able to find solution to this or not But I had the same problem and the reason this was happening was that I had a file included named multimon.h

Looks like in case of 64 bit compilation, due to Macro definitions, the definitions of these functions are coming from two sources and probably one from multimon.h is overriding and is wrong.

I solved it by just commenting out this include and it has started to link fine.

//#include <multimon.h>