Delphi – Enumerating a List of systems Com Ports in Delphi

If the original is reading the registry, and you are porting the function, reading the registry looks like a perfectly valid solution to me?

By the way, Delphi has the class TRegistry from the unit registry.pas. You can use that to read and write the registry. By default you are asking for all the rights (read/write..) on vista this can be a problem, so be sure to open readonly if you are planning to read only.

Key values:

KEY_READ
KEY_WRITE 
KEY_EXECUTE
KEY_ALL_ACCESS

These are actually sets made of the basic values:

KEY_QUERY_VALUE       
KEY_SET_VALUE         
KEY_CREATE_SUB_KEY    
KEY_ENUMERATE_SUB_KEYS
KEY_NOTIFY     
KEY_CREATE_LINK
KEY_WOW64_32KEY
KEY_WOW64_64KEY
KEY_WOW64_RES

The following procedure is working correctly for me (in Windows 8.1). It is important to use the parameter KEY_READ in the TRegistry.Constructor.

procedure  EnumComPorts(const   Ports:  TStringList);

var
  nInd:  Integer;

begin  { EnumComPorts }
  with  TRegistry.Create(KEY_READ)  do
    try
      RootKey := HKEY_LOCAL_MACHINE;
      if  OpenKey('hardware\devicemap\serialcomm', False)  then
        try
          Ports.BeginUpdate();
          try
            GetValueNames(Ports);
            for  nInd := Ports.Count - 1  downto  0  do
              Ports.Strings[nInd] := ReadString(Ports.Strings[nInd]);
            Ports.Sort()
          finally
            Ports.EndUpdate()
          end { try-finally }
        finally
          CloseKey()
        end { try-finally }
      else
        Ports.Clear()
    finally
      Free()
    end { try-finally }
end { EnumComPorts };