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2004-08-07 01:03:44 AM
cppbuilder35
I have an app that will let the user assign hardware to different serial
ports. I just want to to find out what serial ports Windows thinks it has.
What is the best way to do this?
Russ G
 

Hi
Having played with a couple of enumerators,
and versions of windows,
here's a simple and most robust version I have found
// Search for existant com ports
TStringList * results = new TStringList;
results->Clear(); // make sure it's empty before using
enumerate( results );
// Build the menu choices
for( int index = 0; index < results->Count; index++ ) {
TMenuItem *NewMenuItem = new TMenuItem(Options);
NewMenuItem->Caption = results->Strings[index];
NewMenuItem->Name = results->Strings[index];
NewMenuItem->OnClick = COMPortClick;
Options->Add( NewMenuItem );
};
results->Clear();
delete results;
void __fastcall TMainForm::enumerate( TStringList * results )
{
AnsiString PortName;
for ( int i = 1; i < 256; i++ )
{
//Form the Raw device name
PortName.printf("COM%i", i);
//Try to open the port
BOOL bSuccess = FALSE;
HANDLE hPort = ::CreateFile(PortName.c_str(), 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 app had the
port open or a general failure
if (dwError == ERROR_ACCESS_DENIED || dwError ==
ERROR_GEN_FAILURE || dwError == ERROR_SHARING_VIOLATION)
bSuccess = TRUE;
}
else
{
//The port was opened successfully
bSuccess = TRUE;
//Don't forget to close the port, since we are going to do
nothing with it anyway
CloseHandle(hPort);
}
//Add the port number to the array which will be returned
if (bSuccess)
results->Add(PortName);
//results->Add(PortName);
}
}
Have Fun
Stephan
"Russell G" < XXXX@XXXXX.COM >wrote in message