我在C++中使用COM端口。我不能超過9較高數量的打開COM端口,例如10用於COM端口檢測這是功能:在C++中打開一個COM端口號碼高於9
WCHAR port_name[7];
WCHAR num_port[4];
for (i=1; i<256; i++)
{
bool bSuccess = false;
wcscpy(port_name,L"COM");
wcscat(port_name,_itow(i,num_port,10));
HANDLE hPort;
//Try to open the port
hPort = CreateFile(L"COM10", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
//hPort = CreateFile(port_name, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
if (hPort == INVALID_HANDLE_VALUE)
{
DWORD dwError = GetLastError();
//Check to see if the error was because some other application had the port open
if (dwError == ERROR_ACCESS_DENIED)
{
bSuccess = TRUE;
j=j+1;
}
}
else //The port was opened successfully
{
bSuccess = TRUE;
j=j+1;
CloseHandle(hPort); //closing the port
}
if (bSuccess)array_ports[j]=i;
}
我不理解爲什麼例如COM10,拋出FFFFFFFF回HANDLE hPort。
hPort = CreateFile(L"COM10", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
COM9,COM8,COM7等工作正常,
hPort = CreateFile(L"COM9", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
它有一個對這個問題的解決方案?
順便說一句,這是一個複雜的串口檢測方式。在Windows註冊表中有一個用於系統中可用串行端口的HKEY_LOCAL_MACHINE \ HARDWARE \ DEVICEMAP \ SERIALCOMM。 – pmed 2012-08-02 11:10:54