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devnode.c
资源名称：VC++USB.rar　[点击查看]
上传用户：hnzyys
上传日期：2015-09-10
资源大小：423k
文件大小：4k
源码类别：

通讯编程

开发平台：

Visual C++

devnode.c：源码内容
  1. /*++
  3. Copyright (c) 1998-1998 Microsoft Corporation
  5. Module Name:
  7.     DEVNODE.C
  9. --*/
  11. //*****************************************************************************
  12. // I N C L U D E S
  13. //*****************************************************************************
  15. #include <windows.h>
  16. #include <basetyps.h>
  17. //typedef DWORD LOG_CONF; // Logical configuration.
  18. #include "cfgmgr32.h"
  20. #include <string.h>
  22. //*****************************************************************************
  23. // G L O B A L S
  24. //*****************************************************************************
  26. CHAR buf[512];  // XXXXX How big does this have to be? Dynamically size it?
  28. //*****************************************************************************
  29. //
  30. // DriverNameToDeviceDesc()
  31. //
  32. // Returns the Device Description of the DevNode with the matching DriverName.
  33. // Returns NULL if the matching DevNode is not found.
  34. //
  35. // The caller should copy the returned string buffer instead of just saving
  36. // the pointer value.  XXXXX Dynamically allocate return buffer?
  37. //
  38. //*****************************************************************************
  40. PCHAR DriverNameToDeviceDesc (PCHAR DriverName)
  41. {
  42.     DEVINST     devInst;
  43.     DEVINST     devInstNext;
  44.     CONFIGRET   cr;
  45.     ULONG       walkDone = 0;
  46.     ULONG       len;
  48.     // Get Root DevNode
  49.     //
  50.     cr = CM_Locate_DevNode(&devInst,
  51.                            NULL,
  52.                            0);
  54.     if (cr != CR_SUCCESS)
  55.     {
  56.         return NULL;
  57.     }
  59.     // Do a depth first search for the DevNode with a matching
  60.     // DriverName value
  61.     //
  62.     while (!walkDone)
  63.     {
  64.         // Get the DriverName value
  65.         //
  66.         len = sizeof(buf);
  67.         cr = CM_Get_DevNode_Registry_Property(devInst,
  68.                                               CM_DRP_DRIVER,
  69.                                               NULL,
  70.                                               buf,
  71.                                               &len,
  72.                                               0);
  74.         // If the DriverName value matches, return the DeviceDescription
  75.         //
  76.         if (cr == CR_SUCCESS && strcmp(DriverName, buf) == 0)
  77.         {
  78.             len = sizeof(buf);
  79.             cr = CM_Get_DevNode_Registry_Property(devInst,
  80.                                                   CM_DRP_DEVICEDESC,
  81.                                                   NULL,
  82.                                                   buf,
  83.                                                   &len,
  84.                                                   0);
  86.             if (cr == CR_SUCCESS)
  87.             {
  88.                 return buf;
  89.             }
  90.             else
  91.             {
  92.                 return NULL;
  93.             }
  94.         }
  96.         // This DevNode didn't match, go down a level to the first child.
  97.         //
  98.         cr = CM_Get_Child(&devInstNext,
  99.                           devInst,
  100.                           0);
  102.         if (cr == CR_SUCCESS)
  103.         {
  104.             devInst = devInstNext;
  105.             continue;
  106.         }
  108.         // Can't go down any further, go across to the next sibling.  If
  109.         // there are no more siblings, go back up until there is a sibling.
  110.         // If we can't go up any further, we're back at the root and we're
  111.         // done.
  112.         //
  113.         for (;;)
  114.         {
  115.             cr = CM_Get_Sibling(&devInstNext,
  116.                                 devInst,
  117.                                 0);
  119.             if (cr == CR_SUCCESS)
  120.             {
  121.                 devInst = devInstNext;
  122.                 break;
  123.             }
  125.             cr = CM_Get_Parent(&devInstNext,
  126.                                devInst,
  127.                                0);
  130.             if (cr == CR_SUCCESS)
  131.             {
  132.                 devInst = devInstNext;
  133.             }
  134.             else
  135.             {
  136.                 walkDone = 1;
  137.                 break;
  138.             }
  139.         }
  140.     }
  142.     return NULL;
  143. }