I was able to get some more specific suggestions by asking the question a different way with different tags.
It turns out there were errors in the delphi3000.com example code, and possibly errors in the JVCL code. After fixing the example code errors, I got it to work. I have not addressed the potential JVCL errors.
Here is the working code (as a simple console app) for enumerating the names of com ports:
{$APPTYPE CONSOLE}
program EnumComPortsTest;
uses
windows,
sysutils,
classes,
setupAPI,
Registry;
{$R *.RES}
var
ComPortStringList : TStringList;
(*
The function below returns a list of available COM-ports
(not open by this or an other process), with friendly names. The list is formatted as follows:
COM1: = Communications Port (COM1)
COM5: = NI Serial Port (Com5)
COM6: = NI Serial Port (Com6)
COM7: = USB Serial Port (COM7)
COM8: = Bluetooth Communications Port (COM8)
COM9: = Bluetooth Communications Port (COM9)
This code originally posted at http://www.delphi3000.com/articles/article_4001.asp?SK=
errors have been fixed so it will work with Delphi 7 and SetupAPI from JVCL
*)
function SetupEnumAvailableComPorts:TstringList;
// Enumerates all serial communications ports that are available and ready to
// be used.
// For the setupapi unit see
// http://homepages.borland.com/jedi/cms/modules/apilib/visit.php?cid=4&lid=3
var
RequiredSize: Cardinal;
GUIDSize: DWORD;
Guid: TGUID;
DevInfoHandle: HDEVINFO;
DeviceInfoData: TSPDevInfoData;
MemberIndex: Cardinal;
PropertyRegDataType: DWord;
RegProperty: Cardinal;
RegTyp: Cardinal;
Key: Hkey;
Info: TRegKeyInfo;
S1,S2: string;
hc: THandle;
begin
Result:=Nil;
//If we cannot access the setupapi.dll then we return a nil pointer.
if not LoadsetupAPI then exit;
try
// get 'Ports' class guid from name
GUIDSize := 1; // missing from original code - need to tell function that the Guid structure contains a single GUID
if SetupDiClassGuidsFromName('Ports',@Guid,GUIDSize,RequiredSize) then begin
//get object handle of 'Ports' class to interate all devices
DevInfoHandle:=SetupDiGetClassDevs(@Guid,Nil,0,DIGCF_PRESENT);
if Cardinal(DevInfoHandle)<>Invalid_Handle_Value then begin
try
MemberIndex:=0;
result:=TStringList.Create;
//iterate device list
repeat
FillChar(DeviceInfoData,SizeOf(DeviceInfoData),0);
DeviceInfoData.cbSize:=SizeOf(DeviceInfoData);
//get device info that corresponds to the next memberindex
if Not SetupDiEnumDeviceInfo(DevInfoHandle,MemberIndex,DeviceInfoData) then
break;
//query friendly device name LIKE 'BlueTooth Communication Port (COM8)' etc
RegProperty:=SPDRP_FriendlyName;{SPDRP_Driver, SPDRP_SERVICE, SPDRP_ENUMERATOR_NAME,SPDRP_PHYSICAL_DEVICE_OBJECT_NAME,SPDRP_FRIENDLYNAME,}
SetupDiGetDeviceRegistryProperty(DevInfoHandle,
DeviceInfoData,
RegProperty,
PropertyRegDataType,
NIL,0,RequiredSize);
SetLength(S1,RequiredSize);
if SetupDiGetDeviceRegistryProperty(DevInfoHandle,DeviceInfoData,
RegProperty,
PropertyRegDataType,
@S1[1],RequiredSize,RequiredSize) then begin
KEY:=SetupDiOpenDevRegKey(DevInfoHandle,DeviceInfoData,DICS_FLAG_GLOBAL,0,DIREG_DEV,KEY_READ);
if key<>INValid_Handle_Value then begin
FillChar(Info, SizeOf(Info), 0);
//query the real port name from the registry value 'PortName'
if RegQueryInfoKey(Key, nil, nil, nil, @Info.NumSubKeys,@Info.MaxSubKeyLen, nil, @Info.NumValues, @Info.MaxValueLen,
@Info.MaxDataLen, nil, @Info.FileTime) = ERROR_SUCCESS then begin
RequiredSize:= Info.MaxValueLen + 1;
SetLength(S2,RequiredSize);
if RegQueryValueEx(KEY,'PortName',Nil,@Regtyp,@s2[1],@RequiredSize)=Error_Success then begin
If (Pos('COM',S2)=1) then begin
//Test if the device can be used
hc:=CreateFile(pchar('\\.\'+S2+#0),
GENERIC_READ or GENERIC_WRITE,
0,
nil,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
0);
if hc<> INVALID_HANDLE_VALUE then begin
Result.Add(Strpas(PChar(S2))+': = '+StrPas(PChar(S1)));
CloseHandle(hc);
end;
end;
end;
end;
RegCloseKey(key);
end;
end;
Inc(MemberIndex);
until False;
//If we did not found any free com. port we return a NIL pointer.
if Result.Count=0 then begin
Result.Free;
Result:=NIL;
end
finally
SetupDiDestroyDeviceInfoList(DevInfoHandle);
end;
end;
end;
finally
UnloadSetupApi;
end;
end;
var
index : integer;
begin
ComPortStringList := SetupEnumAvailableComPorts;
if (ComPortStringList <> nil) and (ComPortStringList.Count > 0) then
for Index := 0 to ComPortStringList.Count - 1 do
writeln(ComPortStringList[Index]);
end.
