According to this stack overflow thread, PJ Naughter has implemented 9 methods to emunerate com port in Windows. That code was namedEnumSerialPorts.





     As my using, I found some method would list non-existed com ports. for example:



My computer com port be :

But the output of  PJ Naughte's EnumSerialPorts be :

CreateFile method reports

COM1

COM4

COM5

COM98

COM99

QueryDosDevice method reports

COM5

COM1

COM98

COM99

COM4

GetDefaultCommConfig method reports

COM1

COM4

COM5

COM98

COM99

Device Manager (SetupAPI - GUID_DEVINTERFACE_COMPORT) reports

COM1 <通訊連接埠>

COM4 <USB Serial Port>

Device Manager (SetupAPI - Ports Device information set) reports

COM99 <Bluetooth Serial Port>

COM4 <USB Serial Port>

COM1 <通訊連接埠>

COM98 <Bluetooth Serial Port>

COM5 <USB-SERIAL CH340>

EnumPorts method reports

COM1

COM2

COM4

COM7

COM8

COM10

COM6

COM5

COM98

COM99

COM9

COM11

COM12

COM13

COM14

COM16

COM17

COM18

COM19

COM20

COM21

COM22

COM23

COM24

COM25

COM26

COM27

COM28

COM29

COM30

COM31

COM32

COM3

WMI method reports

COM1 <通訊連接埠 (COM1)>

ComDB method reports

COM1

COM3

COM4

COM5

COM6

COM7

COM8

COM9

COM22

COM23

COM24

COM25

COM26

COM27

COM28

COM29

COM30

COM31

COM32

COM98

COM99

Registry method reports

COM98

COM99

COM5

COM1

COM4

Otherwise, that code are too extrvagen, those is hard to separate into an individual function: it is too much dependency on the other functions.



I has reorganized those functions being independent forms in C(instead of C++), those are more portable and useful. I also eliminated some methods which would report unused com ports.



My code be :

/*

 Enumerating com ports in Windows 

 original by PJ Naughter, 1998 - 2013

 http://www.naughter.com/enumser.html  (Web: www.naughter.com, Email: pjna@naughter.com)

 reorganize by Gaiger Chen , Jul, 2015

 NO COPYRIGHT,  welcome to use for everyone.

*/

#include <windows.h>

#include <stdio.h>

#include <tchar.h>

#include <setupapi.h>

#include <locale.h>

#define MAX_PORT_NUM      (256)

#define MAX_STR_LEN       (256*sizeof(TCHAR))

/*assure portName be double ARRAY , not double point*/

BOOL EnumerateComPortByCreateFile(UINT *pNumber, TCHAR *pPortName, int strMaxLen)

{

 UINT i, jj;

 INT ret;

 TCHAR *pTempPortName; 

 *pNumber = 0;

 jj = 0;

 pTempPortName = (TCHAR*)HeapAlloc(GetProcessHeap(),

    HEAP_GENERATE_EXCEPTIONS|HEAP_ZERO_MEMORY,

    strMaxLen*sizeof(pTempPortName));

 ret = FALSE;

 for (i = 1; i<= 255; i++){

  HANDLE hSerial;

  _stprintf_s(pTempPortName, strMaxLen, TEXT("\\\\.\\COM%u"), i);

  hSerial = CreateFile(pTempPortName, GENERIC_READ | GENERIC_WRITE,

   0, 0, OPEN_EXISTING, 0, 0);

  if(INVALID_HANDLE_VALUE == hSerial)

   continue;

  _tcsncpy(pPortName + jj*strMaxLen, pTempPortName,

   _tcsnlen(pTempPortName, strMaxLen));

  jj++;

 }/*for [i MAX_PORT_NUM] */

 HeapFree(GetProcessHeap(), 0, pTempPortName); pTempPortName = NULL;

 *pNumber = jj;

 if(0 <jj)

  ret = TRUE;

 return ret;

}/*EnumerateComPortByCreateFile*/

BOOL EnumerateComPortQueryDosDevice(UINT *pNumber, TCHAR *pPortName, int strMaxLen)

{

 UINT i, jj;

 INT ret;

 OSVERSIONINFOEX osvi;

 ULONGLONG dwlConditionMask;

 DWORD dwChars;

 TCHAR *pDevices;

 UINT nChars;

 ret = FALSE;

 memset(&osvi, 0, sizeof(osvi));

 osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);

 osvi.dwPlatformId = VER_PLATFORM_WIN32_NT;

 dwlConditionMask = 0;

 VER_SET_CONDITION(dwlConditionMask, VER_PLATFORMID, VER_EQUAL);

 if(FALSE == VerifyVersionInfo(&osvi, VER_PLATFORMID, dwlConditionMask))

 {

   DWORD dwError = GetLastError();

  _tprintf(TEXT("VerifyVersionInfo error, %d\n", dwError));

  return -1;

 }/*if*/

 pDevices = NULL;

 nChars = 4096;

 pDevices = (TCHAR*)HeapAlloc(GetProcessHeap(),

  HEAP_GENERATE_EXCEPTIONS, nChars*sizeof(TCHAR));

 while(0 < nChars)

 {

  dwChars = QueryDosDevice(NULL, pDevices, nChars);

  if(0 == dwChars)

  {

   DWORD dwError = GetLastError();

   if(ERROR_INSUFFICIENT_BUFFER == dwError)

   {

    nChars *= 2;

    HeapFree(GetProcessHeap(), 0, pDevices);

    pDevices = (TCHAR*)HeapAlloc(GetProcessHeap(),

     HEAP_GENERATE_EXCEPTIONS, nChars*sizeof(TCHAR));

    continue;

   }/*if ERROR_INSUFFICIENT_BUFFER == dwError*/

   _tprintf(TEXT("QueryDosDevice error, %d\n", dwError));

   return -1;

  }/*if */

  //printf("dwChars = %d\n", dwChars);

  i = 0;

  jj = 0;

  while (TEXT('\0') != pDevices[i] )

  {

   TCHAR* pszCurrentDevice;

   size_t nLen;

   pszCurrentDevice = &(pDevices[i]);

   nLen = _tcslen(pszCurrentDevice);

   //_tprintf(TEXT("%s\n"), &pTargetPathStr[i]);

   if (3 < nLen)

            {

              if ((0 == _tcsnicmp(pszCurrentDevice, TEXT("COM"), 3))

      && FALSE != isdigit(pszCurrentDevice[3]) )

              {

                //Work out the port number

    _tcsncpy(pPortName + jj*strMaxLen,

     pszCurrentDevice, MAX_STR_LEN);

    jj++; 

              }

            }

   i += (nLen + 1);

  }

  break;

 }/*while*/

 if(NULL != pDevices)

  HeapFree(GetProcessHeap(), 0, pDevices); 

 *pNumber = jj;

 if(0 < jj)

  ret = TRUE;

 return ret;

}/*EnumerateComPortByQueryDosDevice*/

BOOL EnumerateComPortByGetDefaultCommConfig(UINT *pNumber, TCHAR *pPortName,

  int strMaxLen)

{

 UINT i, jj;

 INT ret;

 TCHAR *pTempPortName; 

 pTempPortName = (TCHAR*)HeapAlloc(GetProcessHeap(),

  HEAP_GENERATE_EXCEPTIONS| HEAP_ZERO_MEMORY, strMaxLen);

 *pNumber = 0;

 jj = 0;

 ret = FALSE;

 for (i = 1; i<=255; i++){    

  //Form the Raw device name

  COMMCONFIG cc;

  DWORD dwSize ;

  dwSize = sizeof(COMMCONFIG);

  _stprintf_s(pTempPortName, strMaxLen/2, TEXT("COM%u"), i);

  if (FALSE == GetDefaultCommConfig(pTempPortName, &cc, &dwSize))

    continue;

  _tcsncpy(pPortName + jj*strMaxLen, pTempPortName,

   _tcsnlen(pTempPortName, strMaxLen));

  jj++;

 }/*for [1 255] */

 HeapFree(GetProcessHeap(), 0, pTempPortName);

  pTempPortName = NULL;

 *pNumber = jj;

 if(0 <jj)

  ret = TRUE;

 return ret;

}/*EnumerateComPortByGetDefaultCommConfig*/

BOOL EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT(UINT *pNumber,

   TCHAR *pPortName, int strMaxLen, TCHAR *pFriendName)

{

 UINT i, jj;

 INT ret;

 TCHAR *pTempPortName;

 HMODULE hLibrary;

 TCHAR szFullPath[_MAX_PATH];

 GUID guid;

 HDEVINFO hDevInfoSet;

 typedef HKEY (__stdcall SetupDiOpenDevRegKeyFunType)

  (HDEVINFO, PSP_DEVINFO_DATA, DWORD, DWORD, DWORD, REGSAM);

 //typedef BOOL (__stdcall SetupDiClassGuidsFromNameFunType)

 // (LPCTSTR, LPGUID, DWORD, PDWORD);

 typedef BOOL (__stdcall SetupDiDestroyDeviceInfoListFunType)

  (HDEVINFO);

 typedef BOOL (__stdcall SetupDiEnumDeviceInfoFunType)

  (HDEVINFO, DWORD, PSP_DEVINFO_DATA);

 typedef HDEVINFO (__stdcall SetupDiGetClassDevsFunType)

  (LPGUID, LPCTSTR, HWND, DWORD);

 typedef BOOL (__stdcall SetupDiGetDeviceRegistryPropertyFunType)

  (HDEVINFO, PSP_DEVINFO_DATA, DWORD, PDWORD, PBYTE, DWORD, PDWORD);

 SetupDiOpenDevRegKeyFunType* SetupDiOpenDevRegKeyFunPtr;

 SetupDiGetClassDevsFunType *SetupDiGetClassDevsFunPtr;

 SetupDiGetDeviceRegistryPropertyFunType *SetupDiGetDeviceRegistryPropertyFunPtr;

 SetupDiDestroyDeviceInfoListFunType *SetupDiDestroyDeviceInfoListFunPtr;

 SetupDiEnumDeviceInfoFunType *SetupDiEnumDeviceInfoFunPtr; 

 BOOL bMoreItems;

 SP_DEVINFO_DATA devInfo;

 ret = FALSE;

 jj = 0;

 szFullPath[0] = _T('\0'); 

 //Get the Windows System32 directory

 if(0 == GetSystemDirectory(szFullPath, _countof(szFullPath)))

 {

  _tprintf(TEXT("CEnumerateSerial::UsingSetupAPI1 failed, Error:%u\n"),

   GetLastError());

  return FALSE;

 }/*if*/

 //Setup the full path and delegate to LoadLibrary

#pragma warning(suppress: 6102) //There is a bug with the SAL annotation of GetSystemDirectory in the Windows 8.1 SDK

 _tcscat_s(szFullPath, _countof(szFullPath), _T("\\"));

 _tcscat_s(szFullPath, _countof(szFullPath), TEXT("SETUPAPI.DLL"));

 hLibrary = LoadLibrary(szFullPath);

 SetupDiOpenDevRegKeyFunPtr =

  (SetupDiOpenDevRegKeyFunType*)GetProcAddress(hLibrary, "SetupDiOpenDevRegKey");

#if defined _UNICODE

 SetupDiGetClassDevsFunPtr =

  (SetupDiGetClassDevsFunType*)GetProcAddress(hLibrary, "SetupDiGetClassDevsW");

 SetupDiGetDeviceRegistryPropertyFunPtr = (SetupDiGetDeviceRegistryPropertyFunType*)

  GetProcAddress(hLibrary, "SetupDiGetDeviceRegistryPropertyW");

#else

 SetupDiGetClassDevsFunPtr =

  (SetupDiGetClassDevsFunType*)GetProcAddress(hLibrary, "SetupDiGetClassDevsA");

 SetupDiGetDeviceRegistryPropertyFunPtr = (SetupDiGetDeviceRegistryPropertyFunType*)

  GetProcAddress(hLibrary, "SetupDiGetDeviceRegistryPropertyA");

#endif

  SetupDiDestroyDeviceInfoListFunPtr = (SetupDiDestroyDeviceInfoListFunType*)

  GetProcAddress(hLibrary, "SetupDiDestroyDeviceInfoList");

 SetupDiEnumDeviceInfoFunPtr = (SetupDiEnumDeviceInfoFunType*)

  GetProcAddress(hLibrary, "SetupDiEnumDeviceInfo");

 guid = GUID_DEVINTERFACE_COMPORT;

 hDevInfoSet = SetupDiGetClassDevsFunPtr(&guid, NULL, NULL,

  DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);

 if (INVALID_HANDLE_VALUE == hDevInfoSet)

 {

  //Set the error to report

  _tprintf(TEXT("error lpfnSETUPDIGETCLASSDEVS, %d"), GetLastError());

  return FALSE;

 }/*if */

 //bMoreItems = TRUE;

 devInfo.cbSize = sizeof(SP_DEVINFO_DATA);

 i = 0;

 jj = 0;

 do

 {

  HKEY hDeviceKey;

  BOOL isFound;

  isFound = FALSE;

  bMoreItems = SetupDiEnumDeviceInfoFunPtr(hDevInfoSet, i, &devInfo); 

  if(FALSE == bMoreItems)

   break;   

  i++;

  hDeviceKey = SetupDiOpenDevRegKeyFunPtr(hDevInfoSet, &devInfo,

   DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_QUERY_VALUE);

  if (INVALID_HANDLE_VALUE != hDeviceKey)

  {

   int nPort;

   size_t nLen;

   LPTSTR pszPortName;

   nPort = 0;

   pszPortName = NULL;

   {

    //First query for the size of the registry value

    DWORD dwType;

    DWORD dwDataSize;

    LONG err;

    DWORD dwAllocatedSize;

    DWORD dwReturnedSize;

    dwType = 0; dwDataSize = 0; 

    err = RegQueryValueEx(hDeviceKey, TEXT("PortName"), NULL,

     &dwType, NULL, &dwDataSize);

    if (ERROR_SUCCESS != err)

     continue;    

    //Ensure the value is a string

    if (dwType != REG_SZ)

     continue;

    //Allocate enough bytes for the return value

    dwAllocatedSize = dwDataSize + sizeof(TCHAR);

    /* +sizeof(TCHAR) is to allow us to NULL terminate

     the data if it is not null terminated in the registry

    */

    pszPortName = (LPTSTR)LocalAlloc(LMEM_FIXED, dwAllocatedSize); 

    if (pszPortName == NULL)

     continue;

    //Recall RegQueryValueEx to return the data

    pszPortName[0] = _T('\0');

    dwReturnedSize = dwAllocatedSize;

    err = RegQueryValueEx(hDeviceKey, TEXT("PortName"), NULL,

     &dwType, (LPBYTE)pszPortName, &dwReturnedSize);

    if (ERROR_SUCCESS != err)

    {

     LocalFree(pszPortName);

     pszPortName = NULL;

     continue;

    }

    //Handle the case where the data just returned is the same size as the allocated size. This could occur where the data

    //has been updated in the registry with a non null terminator between the two calls to ReqQueryValueEx above. Rather than

    //return a potentially non-null terminated block of data, just fail the method call

    if (dwReturnedSize >= dwAllocatedSize)

     continue;        

    //NULL terminate the data if it was not returned NULL terminated because it is not stored null terminated in the registry

    if (pszPortName[dwReturnedSize/sizeof(TCHAR) - 1] != _T('\0'))

     pszPortName[dwReturnedSize/sizeof(TCHAR)] = _T('\0');

   }/*local varable*/

   //If it looks like "COMX" then

   //add it to the array which will be returned

   nLen = _tcslen(pszPortName);

   if (3 < nLen)

   {

     if (0 == _tcsnicmp(pszPortName, TEXT("COM"), 3))

     {

     if(FALSE == isdigit(pszPortName[3]) )

      continue;

    //Work out the port number

     _tcsncpy(pPortName + jj*strMaxLen, pszPortName,

     _tcsnlen(pszPortName, strMaxLen));

    //_stprintf_s(&portName[jj][0], strMaxLen, TEXT("%s"), pszPortName);

     } else

     {

      continue;

     }/*if 0 == _tcsnicmp(pszPortName, TEXT("COM"), 3)*/

   }/*if 3 < nLen*/

   LocalFree(pszPortName);

   isFound = TRUE;   

   //Close the key now that we are finished with it

   RegCloseKey(hDeviceKey);

  }/*INVALID_HANDLE_VALUE != hDeviceKey*/

  if(FALSE == isFound)

   continue;

  //If the port was a serial port, then also try to get its friendly name

  {

   TCHAR szFriendlyName[1024];

   DWORD dwSize;

   DWORD dwType;

   szFriendlyName[0] = _T('\0');

   dwSize = sizeof(szFriendlyName);

   dwType = 0;

   if( (TRUE == SetupDiGetDeviceRegistryPropertyFunPtr(hDevInfoSet, &devInfo,

       SPDRP_DEVICEDESC, &dwType, (PBYTE)(szFriendlyName),

       dwSize, &dwSize) ) && (REG_SZ == dwType)

   )

   {

    _tcsncpy(pFriendName + jj*strMaxLen, &szFriendlyName[0],

     _tcsnlen(&szFriendlyName[0], strMaxLen));

   }

   else

   {

    _stprintf_s(pFriendName + jj*strMaxLen, strMaxLen, TEXT(""));

   }/*if SetupDiGetDeviceRegistryPropertyFunPtr */

  }/*local variable */

  jj++;

 }while(1);

 *pNumber = jj;

 if(0 <jj)

  ret = TRUE;

 return ret;

}/*EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT*/

BOOL EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort(UINT *pNumber,

  TCHAR *pPortName, int strMaxLen, TCHAR *pFriendName)

{

 UINT i, jj;

 INT ret;

 TCHAR *pTempPortName;

 HMODULE hLibrary;

 TCHAR szFullPath[_MAX_PATH];

 GUID *pGuid;

 DWORD dwGuids;

 HDEVINFO hDevInfoSet;

 typedef HKEY (__stdcall SetupDiOpenDevRegKeyFunType)

  (HDEVINFO, PSP_DEVINFO_DATA, DWORD, DWORD, DWORD, REGSAM);

 typedef BOOL (__stdcall SetupDiClassGuidsFromNameFunType)

  (LPCTSTR, LPGUID, DWORD, PDWORD);

 typedef BOOL (__stdcall SetupDiDestroyDeviceInfoListFunType)

  (HDEVINFO);

 typedef BOOL (__stdcall SetupDiEnumDeviceInfoFunType)

  (HDEVINFO, DWORD, PSP_DEVINFO_DATA);

 typedef HDEVINFO (__stdcall SetupDiGetClassDevsFunType)

  (LPGUID, LPCTSTR, HWND, DWORD);

 typedef BOOL (__stdcall SetupDiGetDeviceRegistryPropertyFunType)

  (HDEVINFO, PSP_DEVINFO_DATA, DWORD, PDWORD, PBYTE, DWORD, PDWORD);

 SetupDiOpenDevRegKeyFunType* SetupDiOpenDevRegKeyFunPtr;

 SetupDiClassGuidsFromNameFunType *SetupDiClassGuidsFromNameFunPtr;

 SetupDiGetClassDevsFunType *SetupDiGetClassDevsFunPtr;

 SetupDiGetDeviceRegistryPropertyFunType *SetupDiGetDeviceRegistryPropertyFunPtr; 

 SetupDiDestroyDeviceInfoListFunType *SetupDiDestroyDeviceInfoListFunPtr;

 SetupDiEnumDeviceInfoFunType *SetupDiEnumDeviceInfoFunPtr; 

 BOOL bMoreItems;

 SP_DEVINFO_DATA devInfo;

 ret = FALSE;

 jj = 0;

 szFullPath[0] = _T('\0'); 

 //Get the Windows System32 directory

 if(0 == GetSystemDirectory(szFullPath, _countof(szFullPath)))

 {

  _tprintf(TEXT("CEnumerateSerial::UsingSetupAPI1 failed, Error:%u\n"),

   GetLastError());

  return FALSE;

 }/*if*/

 //Setup the full path and delegate to LoadLibrary

#pragma warning(suppress: 6102) //There is a bug with the SAL annotation of GetSystemDirectory in the Windows 8.1 SDK

 _tcscat_s(szFullPath, _countof(szFullPath), _T("\\"));

 _tcscat_s(szFullPath, _countof(szFullPath), TEXT("SETUPAPI.DLL"));

 hLibrary = LoadLibrary(szFullPath);

 SetupDiOpenDevRegKeyFunPtr =

  (SetupDiOpenDevRegKeyFunType*)GetProcAddress(hLibrary, "SetupDiOpenDevRegKey");

#if defined _UNICODE

 SetupDiClassGuidsFromNameFunPtr = (SetupDiClassGuidsFromNameFunType*)

  GetProcAddress(hLibrary, "SetupDiGetDeviceRegistryPropertyW");

 SetupDiGetClassDevsFunPtr =

  (SetupDiGetClassDevsFunType*)GetProcAddress(hLibrary, "SetupDiGetClassDevsW");

 SetupDiGetDeviceRegistryPropertyFunPtr

  = (SetupDiGetDeviceRegistryPropertyFunType*)GetProcAddress(hLibrary, "SetupDiGetDeviceRegistryPropertyW");

#else

 SetupDiClassGuidsFromNameFunPtr = (SetupDiClassGuidsFromNameFunType*)

  GetProcAddress(hLibrary, "SetupDiClassGuidsFromNameA");

 SetupDiGetClassDevsFunPtr = (SetupDiGetClassDevsFunType*)

  GetProcAddress(hLibrary, "SetupDiGetClassDevsA");

 SetupDiGetDeviceRegistryPropertyFunPtr = (SetupDiGetDeviceRegistryPropertyFunType*)

  GetProcAddress(hLibrary, "SetupDiGetDeviceRegistryPropertyA");

#endif

  SetupDiDestroyDeviceInfoListFunPtr = (SetupDiDestroyDeviceInfoListFunType*)

  GetProcAddress(hLibrary, "SetupDiDestroyDeviceInfoList");

 SetupDiEnumDeviceInfoFunPtr = (SetupDiEnumDeviceInfoFunType*)

  GetProcAddress(hLibrary, "SetupDiEnumDeviceInfo");

 //First need to convert the name "Ports" to a GUID using SetupDiClassGuidsFromName

 dwGuids = 0;

 SetupDiClassGuidsFromNameFunPtr(TEXT("Ports"), NULL, 0, &dwGuids);

 if(0 == dwGuids)

  return FALSE;

 //Allocate the needed memory

 pGuid = (GUID*)HeapAlloc(GetProcessHeap(),

  HEAP_GENERATE_EXCEPTIONS, dwGuids * sizeof(GUID));

 if(NULL == pGuid)

  return FALSE;

 //Call the function again

 if (FALSE == SetupDiClassGuidsFromNameFunPtr(TEXT("Ports"),

   pGuid, dwGuids, &dwGuids))

 {

  return FALSE;

 }/*if*/

 hDevInfoSet = SetupDiGetClassDevsFunPtr(pGuid, NULL, NULL,

  DIGCF_PRESENT /*| DIGCF_DEVICEINTERFACE*/);

 if (INVALID_HANDLE_VALUE == hDevInfoSet)

 {

  //Set the error to report

  _tprintf(TEXT("error SetupDiGetClassDevsFunPtr, %d"), GetLastError());

  return FALSE;

 }/*if */

 //bMoreItems = TRUE;

 devInfo.cbSize = sizeof(SP_DEVINFO_DATA);

 i = 0;

 jj = 0;

 do

 {

  HKEY hDeviceKey;

  BOOL isFound;

  isFound = FALSE;

  bMoreItems = SetupDiEnumDeviceInfoFunPtr(hDevInfoSet, i, &devInfo);

  if(FALSE == bMoreItems)

   break;   

  i++;

  hDeviceKey = SetupDiOpenDevRegKeyFunPtr(hDevInfoSet, &devInfo,

   DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_QUERY_VALUE);

  if (INVALID_HANDLE_VALUE != hDeviceKey)

  {

   int nPort;

   size_t nLen;

   LPTSTR pszPortName;

   nPort = 0;

   pszPortName = NULL;

   {

    //First query for the size of the registry value

    DWORD dwType;

    DWORD dwDataSize;

    LONG err;

    DWORD dwAllocatedSize;

    DWORD dwReturnedSize;

    dwType = 0; dwDataSize = 0; 

    err = RegQueryValueEx(hDeviceKey, TEXT("PortName"), NULL,

     &dwType, NULL, &dwDataSize);

    if (ERROR_SUCCESS != err)

     continue;    

    //Ensure the value is a string

    if (dwType != REG_SZ)

     continue;

    //Allocate enough bytes for the return value

    dwAllocatedSize = dwDataSize + sizeof(TCHAR);

    /* +sizeof(TCHAR) is to allow us to NULL terminate

     the data if it is not null terminated in the registry

    */

    pszPortName = (LPTSTR)LocalAlloc(LMEM_FIXED, dwAllocatedSize); 

    if (pszPortName == NULL)

     continue;

    //Recall RegQueryValueEx to return the data

    pszPortName[0] = TEXT('\0');

    dwReturnedSize = dwAllocatedSize;

    err = RegQueryValueEx(hDeviceKey, TEXT("PortName"), NULL,

     &dwType, (LPBYTE)pszPortName, &dwReturnedSize);

    if (ERROR_SUCCESS != err)

    {

     LocalFree(pszPortName);

     pszPortName = NULL;

     continue;

    }

    //Handle the case where the data just returned is the same size as the allocated size. This could occur where the data

    //has been updated in the registry with a non null terminator between the two calls to ReqQueryValueEx above. Rather than

    //return a potentially non-null terminated block of data, just fail the method call

    if (dwReturnedSize >= dwAllocatedSize)

     continue;        

    //NULL terminate the data if it was not returned NULL terminated because it is not stored null terminated in the registry

    if (pszPortName[dwReturnedSize/sizeof(TCHAR) - 1] != _T('\0'))

     pszPortName[dwReturnedSize/sizeof(TCHAR)] = _T('\0');

   }/*local varable*/

   //If it looks like "COMX" then

   //add it to the array which will be returned

   nLen = _tcslen(pszPortName);

   if (3 < nLen)

   {

     if (0 == _tcsnicmp(pszPortName, TEXT("COM"), 3))

     {

     if(FALSE == isdigit(pszPortName[3]) )

      continue;

    //Work out the port number

     _tcsncpy(pPortName + jj*strMaxLen, pszPortName,

     _tcsnlen(pszPortName, strMaxLen));

    //_stprintf_s(&portName[jj][0], strMaxLen, TEXT("%s"), pszPortName);

     }

     else

     {

      continue;

     }/*if 0 == _tcsnicmp(pszPortName, TEXT("COM"), 3)*/

   }/*if 3 < nLen*/

   LocalFree(pszPortName);

   isFound = TRUE;  

   //Close the key now that we are finished with it

   RegCloseKey(hDeviceKey);

  }/*INVALID_HANDLE_VALUE != hDeviceKey*/

  if(FALSE == isFound)

   continue;

  //If the port was a serial port, then also try to get its friendly name

  {

   TCHAR szFriendlyName[1024];

   DWORD dwSize;

   DWORD dwType;

   szFriendlyName[0] = _T('\0');

   dwSize = sizeof(szFriendlyName);

   dwType = 0;

   if( (TRUE == SetupDiGetDeviceRegistryPropertyFunPtr(hDevInfoSet, &devInfo,

       SPDRP_DEVICEDESC, &dwType, (PBYTE)(szFriendlyName),

       dwSize, &dwSize) ) && (REG_SZ == dwType)

   )

   {

    _tcsncpy(pFriendName + jj*strMaxLen, &szFriendlyName[0],

     _tcsnlen(&szFriendlyName[0], strMaxLen));

   }

   else

   {

    _stprintf_s(pFriendName + jj*strMaxLen, strMaxLen, TEXT(""));

   }/*if SetupDiGetDeviceRegistryPropertyFunPtr */

  }/*local variable */

  jj++;

 }while(1);

 HeapFree(GetProcessHeap(), 0, pGuid);

 *pNumber = jj;

 if(0 <jj)

  ret = TRUE;

 return ret;

}/*EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort*/

BOOL EnumerateComPortRegistry(UINT *pNumber, TCHAR *pPortName, int strMaxLen)

{

  //What will be the return value from this function (assume the worst)

 UINT jj;

 BOOL ret;

 HKEY hSERIALCOMM;

 ret = FALSE;

 if ( ERROR_SUCCESS == RegOpenKeyEx(HKEY_LOCAL_MACHINE,

  TEXT("HARDWARE\\DEVICEMAP\\SERIALCOMM"), 0, KEY_QUERY_VALUE, &hSERIALCOMM)

  )

 {

    //Get the max value name and max value lengths

  DWORD dwMaxValueNameLen;

  DWORD dwMaxValueLen;

  DWORD dwQueryInfo;

  dwQueryInfo = RegQueryInfoKey(hSERIALCOMM, NULL, NULL,

  NULL, NULL, NULL, NULL, NULL,

  &dwMaxValueNameLen, &dwMaxValueLen, NULL, NULL);

  if(ERROR_SUCCESS == dwQueryInfo)

  {

   DWORD dwMaxValueNameSizeInChars, dwMaxValueNameSizeInBytes,

    dwMaxValueDataSizeInChars, dwMaxValueDataSizeInBytes;

   DWORD *pValueName;

   DWORD *pValueData;

   dwMaxValueNameSizeInChars = dwMaxValueNameLen + 1; //Include space for the NULL terminator

   dwMaxValueNameSizeInBytes = dwMaxValueNameSizeInChars * sizeof(TCHAR);

   dwMaxValueDataSizeInChars = dwMaxValueLen/sizeof(TCHAR) + 1; //Include space for the NULL terminator

   dwMaxValueDataSizeInBytes = dwMaxValueDataSizeInChars * sizeof(TCHAR);

   //Allocate some space for the value name and value data      

   pValueName = (GUID*)HeapAlloc(GetProcessHeap(),

    HEAP_GENERATE_EXCEPTIONS| HEAP_ZERO_MEMORY, dwMaxValueNameSizeInBytes);

   pValueData = (GUID*)HeapAlloc(GetProcessHeap(),

    HEAP_GENERATE_EXCEPTIONS| HEAP_ZERO_MEMORY, dwMaxValueDataSizeInBytes);

   if(NULL != pValueName && NULL != pValueData)

   {

    //Enumerate all the values underneath HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM

    DWORD i;

    DWORD dwType;

    DWORD dwValueNameSize;

    DWORD dwDataSize;

    LONG nEnum;

    dwValueNameSize = dwMaxValueNameSizeInChars;

    dwDataSize = dwMaxValueDataSizeInBytes;

    i = 0; 

    nEnum = RegEnumValue(hSERIALCOMM, i,

     pValueName, &dwValueNameSize, NULL, &dwType,

     pValueData, &dwDataSize);

    jj = 0;

    while (ERROR_SUCCESS == nEnum)

    {

      //If the value is of the correct type, then add it to the array

     if (REG_SZ == dwType)

     {

      _stprintf_s(pPortName + jj*strMaxLen,

       strMaxLen, TEXT("%s"), pValueData);

      jj++;

     }/*if */

     //Prepare for the next time around

     dwValueNameSize = dwMaxValueNameSizeInChars;

     dwDataSize = dwMaxValueDataSizeInBytes;

     ZeroMemory(pValueName, dwMaxValueNameSizeInBytes);

     ZeroMemory(pValueData, dwMaxValueDataSizeInBytes);

     i++;

     nEnum = RegEnumValue(hSERIALCOMM, i, pValueName,

       &dwValueNameSize, NULL, &dwType, pValueData, &dwDataSize);

    }/*while*/

   }

   else

   {

    return FALSE;

   }/*if NULL != pValueName && NULL != pValueData*/

   HeapFree(GetProcessHeap(), 0, pValueName);

   HeapFree(GetProcessHeap(), 0, pValueData);

  }/*ERROR_SUCCESS == dwQueryInfo*/

  //Close the registry key now that we are finished with it

  RegCloseKey(hSERIALCOMM);

  if (dwQueryInfo != ERROR_SUCCESS)

    return FALSE;

 }/*ERROR_SUCCESS == RegOpenKeyEx*/

 *pNumber = jj;

 if(0 <jj)

  ret = TRUE;

 return ret;

}/*EnumerateComPortRegistry*/

#define TIMER_BEGIN(TIMER_LABEL) \

   { unsigned int tBegin##TIMER_LABEL, tEnd##TIMER_LABEL; \

   tBegin##TIMER_LABEL = GetTime();

#define TIMER_END(TIMER_LABEL)  \

   tEnd##TIMER_LABEL = GetTime();\

   fprintf(stderr, "%s cost time = %d ms\n", \

   #TIMER_LABEL, tEnd##TIMER_LABEL - tBegin##TIMER_LABEL); \

   }

unsigned int GetTime(void)

{

 /*winmm.lib*/

 return ( unsigned int)timeGetTime();

}/*GetTime*/

int main(int argc, TCHAR argv[])

{

 TCHAR portName[MAX_PORT_NUM][MAX_STR_LEN];

 TCHAR friendlyName[MAX_PORT_NUM][MAX_STR_LEN];

 UINT i;

 UINT n;

 char* nativeLocale;

 nativeLocale = _strdup( setlocale(LC_CTYPE,NULL) );

 for(i = 0; i< MAX_PORT_NUM; i++)

  ZeroMemory(&portName[i][0], MAX_STR_LEN);

 _tprintf(TEXT("\nCreateFile method : \n"));

TIMER_BEGIN(EnumerateComPortByCreateFile);

 EnumerateComPortByCreateFile(&n, &portName[0][0], MAX_STR_LEN);

TIMER_END(EnumerateComPortByCreateFile);

 _tprintf(TEXT("sought %d:\n"), n);

 for(i = 0; i< n; i++)

  _tprintf(TEXT("\t%s\n"), &portName[i][0]);

 for(i = 0; i< MAX_PORT_NUM; i++)

  ZeroMemory(&portName[0][0], MAX_STR_LEN);

 _tprintf(TEXT("\nQueryDosDevice method : "));

TIMER_BEGIN(EnumerateComPortQueryDosDevice);

 EnumerateComPortQueryDosDevice(&n, &portName[0][0], MAX_STR_LEN);

TIMER_END(EnumerateComPortQueryDosDevice);

 _tprintf(TEXT("sought %d:\n"), n);

 for(i = 0; i< n; i++)

  _tprintf("\t%s\n", &portName[i][0]);

 for(i = 0; i< MAX_PORT_NUM; i++)

  ZeroMemory(&portName[i][0], MAX_STR_LEN);

 _tprintf(TEXT("\nGetDefaultCommConfig method : \n"));

TIMER_BEGIN(EnumerateComPortByGetDefaultCommConfig);

 EnumerateComPortByGetDefaultCommConfig(&n, &portName[0][0], MAX_STR_LEN);

TIMER_END(EnumerateComPortByGetDefaultCommConfig);

 _tprintf(TEXT("sought %d:\n"), n);

 for(i = 0; i< n; i++)

  _tprintf(TEXT("\t%s\n"), &portName[i][0]);

 for(i = 0; i< MAX_PORT_NUM; i++){

  ZeroMemory(&portName[i][0], MAX_STR_LEN);

  ZeroMemory(&friendlyName[i][0], MAX_STR_LEN);

 }/*for i[i MAX_PORT_NUM]*/

 _tprintf(TEXT("\nSetupAPI GUID_DEVINTERFACE_COMPORT method : \n")); 

TIMER_BEGIN(EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT);

 EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT(&n, &portName[0][0],

  MAX_STR_LEN, &friendlyName[0][0]);

TIMER_END(EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT);

 _tprintf(TEXT("sought %d:\n"), n);

 setlocale(LC_CTYPE, "" );

 for(i = 0; i< n; i++)

  _tprintf(TEXT("\t%s <%s> \n"), &portName[i][0],  &friendlyName[i][0]);

 setlocale(LC_CTYPE, nativeLocale);

 for(i = 0; i< MAX_PORT_NUM; i++){

  ZeroMemory(&portName[i][0], MAX_STR_LEN);

  ZeroMemory(&friendlyName[i][0], MAX_STR_LEN);

 }/*for i[i MAX_PORT_NUM]*/

 _tprintf(TEXT("\nSetupAPI SetupDiClassGuidsFromNamePort method : \n"));

TIMER_BEGIN(EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort);

 EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort(&n, &portName[0][0],

  MAX_STR_LEN, &friendlyName[0][0]);

TIMER_END(EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort);

 _tprintf(TEXT("sought %d:\n"), n);

 setlocale(LC_CTYPE, "" );

 for(i = 0; i< n; i++)

  _tprintf(TEXT("\t%s <%s> \n"), &portName[i][0],  &friendlyName[i][0]);

 setlocale(LC_CTYPE, nativeLocale);

 for(i = 0; i< MAX_PORT_NUM; i++)

  ZeroMemory(&portName[i][0], MAX_STR_LEN);

 _tprintf(TEXT("\nRegistry method : \n"));

TIMER_BEGIN(EnumerateComPortRegistry);

 EnumerateComPortRegistry(&n, &portName[0][0], MAX_STR_LEN);

TIMER_END(EnumerateComPortRegistry);

 _tprintf(TEXT("sought %d:\n"), n);

 for(i = 0; i< n; i++)

  _tprintf(TEXT("\t%s\n"), &portName[i][0]);

 return 0;

}/*main*/

The output be :

CreateFile method :

EnumerateComPortByCreateFile cost time = 35 ms

sought 5:

        \\.\COM1

        \\.\COM4

        \\.\COM5

        \\.\COM98

        \\.\COM99

QueryDosDevice method : EnumerateComPortQueryDosDevice cost time = 7 ms

sought 5:

        COM5

        COM1

        COM98

        COM99

        COM4

GetDefaultCommConfig method :

EnumerateComPortByGetDefaultCommConfig cost time = 772 ms

sought 5:

        COM1

        COM4

        COM5

        COM98

        COM99

SetupAPI GUID_DEVINTERFACE_COMPORT method :

EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT cost time = 12 ms

sought 2:

        COM1 <通訊連接埠>

        COM4 <USB Serial Port>

SetupAPI SetupDiClassGuidsFromNamePort method :

EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort cost time = 10 ms

sought 5:

        COM99 <Bluetooth Serial Port>

        COM4 <USB Serial Port>

        COM1 <通訊連接埠>

        COM98 <Bluetooth Serial Port>

        COM5 <USB-SERIAL CH340>

Registry method :

EnumerateComPortRegistry cost time = 0 ms

sought 5:

        COM98

        COM99

        COM5

        COM1

        COM4

Note that: EnumerateComPortSetupAPI_GUID_DEVINTERFACE_COMPORT

would not list CH340 port, which is on an Arduino UNO board. (But the same function could list other CH340 port, if it is not on this Arduino). Besides,  this function could not list Bluetooth virtual com ports.

     

     If you would like to use my code, I suggest you use function

BOOL EnumerateComPortSetupAPISetupDiClassGuidsFromNamePort(UINT *pNumber,

  TCHAR *pPortName, int strMaxLen, TCHAR *pFriendName)

That is the best one which balances speed and detail; but this one are most complicated in implementation. Otherwise, if you want to implement a function which could list com ports as simple as possible, I recommend use theCreateFilemethod:
that is rudimentary, but sufficient.

Methods Collection of Enumerating Com Port in Windows, by C的更多相关文章

  1. Seeking USB Serial Com Port in Windows Automatically : via PID VID

    After you read previous article, you might know how to operate a com port in Windows.    But that ex ...

  2. 将cocos2dx+lua创建的游戏port到windows phone

    在整个Port的过程中遇到的问题总结例如以下 1.一定要使用最新版本号的cocos2dx,原因大家看一下changelog就知道了,近期的cocos2dx版本号都是在修windows phone上的b ...

  3. kill 8080 port on windows

    1. 查找PID netstat -ano | findstr :yourPortNumber 2. kill进程 taskkill /PID typeyourPIDhere /F

  4. windows防火墙添加规则

    #include <windows.h> #include <crtdbg.h> #include <netfw.h> #include <objbase.h ...

  5. Serial Port Programming using Win32 API(转载)

    In this tutorial we will learn How to communicate with an external device like a microcontroller boa ...

  6. Native code on Windows Phone 8（转）

    Windows Phone 8 introduces the ability to use native code to implement Windows Phone. In this sectio ...

  7. windows下的mysql客户端mysqlworkbench链接虚拟机上CentOS的mysql服务器

    本人在虚拟机上CentOS的Linux环境下安装了mysql服务器,在本地Windows下安装了mysql的客户端mysqlworkbench ,所以就想让windows下的mysql客户端mysql ...

  8. windows环境安装weblogic服务【转】【补】

    我的环境: windows: win10 professional edition jdk: C:\Program Files\Java\jdk1.6.0_45 weblogic安装目录 (WEBLO ...

  9. mongodb在windows下的安装

    Windows下安装MongoDB 1.下载MongoDB数据库http://fastdl.mongodb.org/win32/mongodb-win32-i386-1.6.5.zip: 2.将安装文 ...

随机推荐

  1. AIX&nbsp;常用命令汇总（一）

    命令 内核 如何知道自己在运行 32 位内核还是 64 位内核? 要显示内核启用的是 32 位还是 64 位,可输入以下命令: bootinfo -K 如何知道自己在运行单处理器还是多处理器内核? / ...

  2. 2015 多校赛 第一场 1002 (hdu 5289)

    Description Tom owns a company and he is the boss. There are n staffs which are numbered from 1 to n ...

  3. Hadoop MapReduce编程 API入门系列之自定义多种输入格式数据类型和排序多种输出格式（十一）

    推荐 MapReduce分析明星微博数据 http://git.oschina.net/ljc520313/codeexample/tree/master/bigdata/hadoop/mapredu ...

  4. .net中的TreeView的数据绑定与EasyUi_tree的数据绑定

    昨天看到了.net中的TreeView,学习了一波TreeView的数据绑定,联想到EasyUi中的Tree的数据,觉得里面的逻辑差不多,就总结了一下两者的数据绑定. 前端页面和必要的JS如下 < ...

  5. 通过阅读《React 进阶之路》之学习笔记

    第一章: React 通过引入虚拟DOM.状态.单向数据流等设计理念,形成以组件为核心,用组件搭建UI的开发模式.

  6. 9) 十分钟学会android--使用Fragment建立动态UI

    为了在 Android 上为用户提供动态的.多窗口的交互体验,需要将 UI 组件和 Activity 操作封装成模块进行使用,这样我们就可以在 Activity 中对这些模块进行切入切出操作.可以用  ...

  7. 获取json的节点名称

    好几次想取json的节点名称,今天搞定了. procedure GetJsonNames(o: ISuperObject; Strs: TStrings); var ite: TSuperAvlIte ...

  8. VHDL之Aggregate

    Definition A basic operation that combines one or more values into a composite value of a record or ...

  9. Qwt--散点图/函数图

    1.Qwt库 QwtPlot是用来绘制二维图像的widget.在它的画板上可以无限制的显示绘画组件.绘画组件可以是曲线(QwtPlotCurve).标记(QwtPlotMarker).网格(QwtPl ...

  10. 【技术累积】【点】【java】【2】聊一聊似曾相识的switch语句

    闲聊 有些东西并不能像爱因斯坦老先生说的那样,书上查的到就不用去记住... 开始 java使用了C的所有流程控制语句: java中同样有switch语句: 大多数情况下,switch都可以用if替换: ...