Q197671: HOWTO: How to Enumerate Monitors in Win 98 and Windows 2000

Article: Q197671
Product(s): Microsoft Windows NT
Version(s): ; WINDOWS:
Operating System(s): 
Keyword(s): kbOSWin2000 kbSDKPlatform kbGrpDSUser kbOSWin98
Last Modified: 21-OCT-2000

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The information in this article applies to:

- Microsoft Windows 2000 Advanced Server 
- Microsoft Windows 2000 Server 
- Microsoft Windows 2000 Professional 
- Microsoft Windows 98 
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and is subject to change without notice.
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SUMMARY
=======

Starting with Microsoft Windows 98 and Microsoft Windows 2000, multiple monitors
could be attached to a computer and connected to the desktop. This article
contains sample code showing how to enumerate those devices attached to the
desktop.

MORE INFORMATION
================

The following code is for a small console-mode application that enumerates the
attached display devices:

Sample Code
-----------

     #include <windows.h>
     #include <stdio.h>
     #ifndef SM_CMONITORS

         typedef HANDLE HMONITOR;

     #endif
     #ifndef DISPLAY_DEVICE_PRIMARY_DEVICE

         typedef struct _DISPLAY_DEVICE {
          DWORD  cb;
          TCHAR  DeviceName[32];
          TCHAR  DeviceString[128];
          DWORD  StateFlags;
         } DISPLAY_DEVICE, *PDISPLAY_DEVICE, *LPDISPLAY_DEVICE;
         #define DISPLAY_DEVICE_ATTACHED_TO_DESKTOP 0x00000001
         #define DISPLAY_DEVICE_MULTI_DRIVER        0x00000002
         #define DISPLAY_DEVICE_PRIMARY_DEVICE      0x00000004
         #define DISPLAY_DEVICE_VGA             0x00000010

     #endif

     main (int argc, char**argv)
     {

      int i;
     int j=0;
      BOOL (WINAPI* pEnumDisplayDevices)(PVOID,DWORD,PVOID,DWORD);

      (FARPROC)pEnumDisplayDevices = GetProcAddress(
          LoadLibrary("USER32"), "EnumDisplayDevicesA");

      if (pEnumDisplayDevices)
      {
          DISPLAY_DEVICE dd;
          ZeroMemory(&dd, sizeof(dd));
          dd.cb = sizeof(dd);

          printf("*** EnumDisplayDevices\n");

          for (i=0; (*pEnumDisplayDevices)(NULL, i, &dd, 0); i++)
          {
           j++;
              printf("    DeviceName:   '%s'\n", dd.DeviceName);
              printf("    DeviceString: '%s'\n", dd.DeviceString);
              printf("    Flags:        %08X %s%s\n",
                  dd.StateFlags,
                  ((dd.StateFlags & DISPLAY_DEVICE_ATTACHED_TO_DESKTOP) ?
  "Desktop " : ""),

                  ((dd.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE) ? "Primary

  " : ""));

             }
         }

     return j;
     }

REFERENCES
==========

MSDN VC++ Documentation

Additional query words:

======================================================================
Keywords          : kbOSWin2000 kbSDKPlatform kbGrpDSUser kbOSWin98 
Technology        : kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Serv kbwin2000ServSearch kbwin2000Search kbwin2000ProSearch kbwin2000Pro kbWin98search kbWinAdvServSearch kbWin98
Version           : :; WINDOWS:
Issue type        : kbhowto

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