#include <windows.h>
#include "multimon.h"    

#define MONITOR_CENTER     0x0001        // center rect to monitor
#define MONITOR_CLIP     0x0000        // clip rect to monitor
#define MONITOR_WORKAREA 0x0002        // use monitor work area
#define MONITOR_AREA     0x0000        // use monitor entire area

//
//  ClipOrCenterRectToMonitor
//
//  The most common problem apps have when running on a
//  multimonitor system is that they "clip" or "pin" windows
//  based on the SM_CXSCREEN and SM_CYSCREEN system metrics.
//  Because of app compatibility reasons these system metrics
//  return the size of the primary monitor.
//
//  This shows how you use the multi-monitor functions
//  to do the same thing.
//
void ClipOrCenterRectToMonitor(LPRECT prc, UINT flags)
{
    HMONITOR hMonitor;
    MONITORINFO mi;
    RECT        rc;
    int         w = prc->right  - prc->left;
    int         h = prc->bottom - prc->top;

    //
    // get the nearest monitor to the passed rect.
    //
    hMonitor = MonitorFromRect(prc, MONITOR_DEFAULTTONEAREST);

    //
    // get the work area or entire monitor rect.
    //
    mi.cbSize = sizeof(mi);
    GetMonitorInfo(hMonitor, &mi);

    if (flags & MONITOR_WORKAREA)
        rc = mi.rcWork;
    else
        rc = mi.rcMonitor;

    //
    // center or clip the passed rect to the monitor rect
    //
    if (flags & MONITOR_CENTER)
    {
        prc->left   = rc.left + (rc.right  - rc.left - w) / 2;
        prc->top    = rc.top  + (rc.bottom - rc.top  - h) / 2;
        prc->right  = prc->left + w;
        prc->bottom = prc->top  + h;
    }
    else
    {
        prc->left   = max(rc.left, min(rc.right-w,  prc->left));
        prc->top    = max(rc.top,  min(rc.bottom-h, prc->top));
        prc->right  = prc->left + w;
        prc->bottom = prc->top  + h;
    }
}

void ClipOrCenterWindowToMonitor(HWND hwnd, UINT flags)
{
    RECT rc;
    GetWindowRect(hwnd, &rc);
    ClipOrCenterRectToMonitor(&rc, flags);
    SetWindowPos(hwnd, NULL, rc.left, rc.top, 0, 0, SWP_NOSIZE | SWP_NOZORDER | SWP_NOACTIVATE);
}

und möchte ihn bei mir implementieren, leider bekomme ich immer diese Fehlermeldungen:

diagtestDlg.obj : error LNK2001: unresolved external symbol _xGetMonitorInfo@8
diagtestDlg.obj : error LNK2001: unresolved external symbol _xMonitorFromRect@8
Debug/diagtest.exe : fatal error LNK1120: 2 unresolved externals
Error executing link.exe.

HMONITOR hMonitor, // handle to display monitor ?

Danke schonmal Patrick