我想列出 COM 埠（就像在“設備管理器”中看到的那樣），但在運行時。
我無恥地從這個網站復制了代碼（代碼顯示在帖子末尾），我想我明白了。但是，程式在第 36 行失敗，給了我錯誤：
Failed to open key 'HARDWARE\DEVICEMAP\SERIALCOMM'
Windows reports error: (0x00000002): The system cannot find the file specified.
如果我打開注冊表編輯器，我會清楚地看到該檔案夾??，當我單擊它時，我會看到我已連接到我的計算機的設備。
我已經使用 MinGW 和命令編譯了代碼gcc filename.c
有想法該怎么解決這個嗎？可能是權限問題？是否有一些 gcc 需要我能夠使用的編譯器標志？
我正在運行的代碼是這樣的：
#define WIN32_LEAN_AND_MEAN // excludes stuff frokm windows.h that we won't need here.
#include <Windows.h>
#include <string.h>
#include <tchar.h>
#include <malloc.h>
void ShowErrorFromLStatus(LSTATUS lResult)
{
LPTSTR psz;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL,
lResult,
0,
(LPTSTR)&psz,
1024,
NULL);
_tprintf(_T("Windows reports error: (0xX): %s\n"), lResult, (psz) ? psz : _T("(null)"));
if (psz)
{
LocalFree(psz);
}
}
int main()
{
DWORD nValues, nMaxValueNameLen, nMaxValueLen;
HKEY hKey = NULL;
LPTSTR szDeviceName = NULL;
LPTSTR szFriendlyName = NULL;
DWORD dwType = 0;
DWORD nValueNameLen = 0;
DWORD nValueLen = 0;
DWORD dwIndex = 0;
LSTATUS lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE, L"HARDWARE\\DEVICEMAP\\SERIALCOMM", 0, KEY_READ, &hKey);
if (ERROR_SUCCESS != lResult)
{
printf("Failed to open key \'HARDWARE\\DEVICEMAP\\SERIALCOMM\' \n");
ShowErrorFromLStatus(lResult);
return 1;
}
lResult = RegQueryInfoKey(hKey, NULL, NULL, NULL, NULL, NULL, NULL,
&nValues, &nMaxValueNameLen, &nMaxValueLen, NULL, NULL);
if (ERROR_SUCCESS != lResult)
{
_tprintf(_T("Failed to RegQueryInfoKey()\n"));
ShowErrorFromLStatus(lResult);
RegCloseKey(hKey);
return 2;
}
szDeviceName = (LPTSTR)malloc(nMaxValueNameLen sizeof(TCHAR));
if (!szDeviceName)
{
_tprintf(_T("malloc() fail\n"));
RegCloseKey(hKey);
return 3;
}
szFriendlyName = (LPTSTR)malloc(nMaxValueLen sizeof(TCHAR));
if (!szFriendlyName)
{
free(szDeviceName);
_tprintf(_T("malloc() fail\n"));
RegCloseKey(hKey);
return 3;
}
_tprintf(_T("Found %d serial device(s) registered with PnP and active or available at the moment.\n"), nValues);
for (DWORD dwIndex = 0; dwIndex < nValues; dwIndex)
{
dwType = 0;
nValueNameLen = nMaxValueNameLen sizeof(TCHAR);
nValueLen = nMaxValueLen sizeof(TCHAR);
lResult = RegEnumValueW(hKey, dwIndex,
szDeviceName, &nValueNameLen,
NULL, &dwType,
(LPBYTE)szFriendlyName, &nValueLen);
if (ERROR_SUCCESS != lResult || REG_SZ != dwType)
{
_tprintf(_T("SerialPortEnumerator::Init() : can't process registry value, index: %d\n"), dwIndex);
ShowErrorFromLStatus(lResult);
continue;
}
_tprintf(_T("Found port \'%s\': Device name for CreateFile(): \'\\.%s\'\n"), szFriendlyName, szDeviceName);
}
free(szDeviceName);
free(szFriendlyName);
RegCloseKey(hKey);
return 0;
}
編輯
I'm now calling RegOpenKeyEx with _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"), and in the call to RegEnumValueW on line 81, I casted szDeviceName to a LPWSTR. gcc no longer gives any errors or warnings. However, when running the program, all that comes out is
Found 1 serial device(s) registered with PnP and active or available at the moment.
Found port 'C': Device name for CreateFile(): '\.\'
And the port I have connected (COM3) does not show up.
Any other advice?
uj5u.com熱心網友回復：
感謝Simon Mourier和Ian Abbott！
如編輯中所述，呼叫RegOpenKeyEx并_T("HARDWARE\\DEVICEMAP\\SERIALCOMM")轉換szDeviceName為已LPWSTR修復的所有錯誤。
%ls此外，在對第 92 行的呼叫中使用識別符號可以_tprintf()正確列印名稱。
最終的作業代碼如下所示：
#define WIN32_LEAN_AND_MEAN // excludes stuff frokm windows.h that we won't need here.
#include <Windows.h>
#include <string.h>
#include <tchar.h>
#include <malloc.h>
#include <stdio.h>
void ShowErrorFromLStatus(LSTATUS lResult)
{
LPTSTR psz;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL,
lResult,
0,
(LPTSTR)&psz,
1024,
NULL);
_tprintf(_T("Windows reports error: (0xX): %s\n"), lResult, (psz) ? psz : _T("(null)"));
if (psz)
{
LocalFree(psz);
}
}
int main()
{
DWORD nValues, nMaxValueNameLen, nMaxValueLen;
HKEY hKey = NULL;
LPTSTR szDeviceName = NULL;
LPTSTR szFriendlyName = NULL;
DWORD dwType = 0;
DWORD nValueNameLen = 0;
DWORD nValueLen = 0;
DWORD dwIndex = 0;
LSTATUS lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"), 0, KEY_READ, &hKey);
if (ERROR_SUCCESS != lResult)
{
printf("Failed to open key \'HARDWARE\\DEVICEMAP\\SERIALCOMM\' \n");
ShowErrorFromLStatus(lResult);
return 1;
}
lResult = RegQueryInfoKey(hKey, NULL, NULL, NULL, NULL, NULL, NULL,
&nValues, &nMaxValueNameLen, &nMaxValueLen, NULL, NULL);
if (ERROR_SUCCESS != lResult)
{
_tprintf(_T("Failed to RegQueryInfoKey()\n"));
ShowErrorFromLStatus(lResult);
RegCloseKey(hKey);
return 2;
}
szDeviceName = (LPTSTR)malloc(nMaxValueNameLen sizeof(TCHAR));
if (!szDeviceName)
{
_tprintf(_T("malloc() fail\n"));
RegCloseKey(hKey);
return 3;
}
szFriendlyName = (LPTSTR)malloc(nMaxValueLen sizeof(TCHAR));
if (!szFriendlyName)
{
free(szDeviceName);
_tprintf(_T("malloc() fail\n"));
RegCloseKey(hKey);
return 3;
}
_tprintf(_T("Found %d serial device(s) registered with PnP and active or available at the moment.\n"), nValues);
for (DWORD dwIndex = 0; dwIndex < nValues; dwIndex)
{
dwType = 0;
nValueNameLen = nMaxValueNameLen sizeof(TCHAR);
nValueLen = nMaxValueLen sizeof(TCHAR);
lResult = RegEnumValueW(hKey, dwIndex,
(LPWSTR)szDeviceName, &nValueNameLen,
NULL, &dwType,
(LPBYTE)szFriendlyName, &nValueLen);
if (ERROR_SUCCESS != lResult || REG_SZ != dwType)
{
_tprintf(_T("SerialPortEnumerator::Init() : can't process registry value, index: %d\n"), dwIndex);
ShowErrorFromLStatus(lResult);
continue;
}
_tprintf(_T("Found port \'%ls\': Device name for CreateFile(): \'\\.%ls\'\n"), szFriendlyName, szDeviceName);
}
free(szDeviceName);
free(szFriendlyName);
RegCloseKey(hKey);
return 0;
}
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