{
The NetGetDCName function returns the name of the primary domain controller (PDC).
It does not return the name of the backup domain controller (BDC) for the specified domain.
Also, you cannot remote this function to a non-PDC server.
Windows 2000/XP: Applications that support DNS-style names should call the function.
Domain controllers in this type of environment have a multi-master
directory replication relationship.
Therefore, it may be advantageous for your application to use a DC that is not the PDC.
You can call the DsGetDcName function to locate any DC in the domain;
NetGetDCName returns only the name of the PDC.
}
type
EAccessDenied = Exception;
EInvalidOwner = Exception;
EInsufficientBuffer = Exception;
ELibraryNotFound = Exception;
NET_API_STATUS = Integer;
const
NERR_Success = 0;
var
NTNetGetDCName: function (Server, Domain: pWideChar; var DC: pWideChar): NET_API_STATUS; stdcall;
NTNetGetDCNameA: function (Server, Domain: PChar; var DC: PChar): NET_API_STATUS; stdcall;
NTNetApiBufferFree: function (lpBuffer: Pointer): NET_API_STATUS; stdcall;
procedure NetCheck(ErrCode: NET_API_STATUS);
begin
if ErrCode <> NERR_Success then
begin
case ErrCode of
ERROR_ACCESS_DENIED:
raise EAccessDenied.Create('Access is Denied');
ERROR_INVALID_OWNER:
raise EInvalidOwner.Create('Cannot assign the owner of this object.');
ERROR_INSUFFICIENT_BUFFER:
raise EInsufficientBuffer.Create('Buffer passed was too small');
else
raise Exception.Create('Error Code: ' + IntToStr(ErrCode) + #13 +
SysErrorMessage(ErrCode));
end;
end;
end;
function GetPDC(szSystem: string): string;
{ if szSystem = '' return the PDC else return DC for that domain }
const
NTlib = 'NETAPI32.DLL';
Win95lib = 'RADMIN32.DLL';
var
pAnsiDomain: PChar;
pDomain: PWideChar;
System: array[1..80] of WideChar;
ErrMode: Word;
LibHandle: THandle;
begin
Result := '';
LibHandle := 0;
try
if Win32Platform = VER_PLATFORM_WIN32_NT then
begin
ErrMode := SetErrorMode(SEM_NOOPENFILEERRORBOX);
LibHandle := LoadLibrary(NTlib);
SetErrorMode(ErrMode);
if LibHandle = 0 then
raise ELibraryNotFound.Create('Unable to map library: ' +
NTlib); @NTNetGetDCName := GetProcAddress(Libhandle, 'NetGetDCName');
@NTNetApiBufferFree := GetProcAddress(Libhandle,
'NetApiBufferFree');
try
if szSystem <> '' then
NetCheck(NTNetGetDCName(nil, StringToWideChar(szSystem, @System, 80), pDomain))
else
NetCheck(NTNetGetDCName(nil, nil, pDomain));
Result := WideCharToString(pDomain);
finally
NetCheck(NTNetApiBufferFree(pDomain));
end;
end
else
begin
ErrMode := SetErrorMode(SEM_NOOPENFILEERRORBOX);
LibHandle := LoadLibrary(Win95lib);
SetErrorMode(ErrMode);
if LibHandle = 0 then
raise ELibraryNotFound.Create('Unable to map library: ' +
Win95lib); @NTNetGetDCNameA := GetProcAddress(Libhandle, 'NetGetDCNameA');
@NTNetApiBufferFree := GetProcAddress(LibHandle, 'NetApiBufferFree');
try
if szSystem <> '' then
NetCheck(NTNetGetDCNameA(nil, PChar(szSystem), pAnsiDomain))
else
NetCheck(NTNetGetDCNameA(nil, nil, pAnsiDomain));
Result := StrPas(pAnsiDomain);
finally
NetCheck(NTNetApiBufferFree(pAnsiDomain));
end;
end;
finally
if LibHandle <> 0 then
begin
FreeLibrary(Libhandle); // free handle if it has been allocated
end;
end;
end;
// Example call, Beispielaufruf:
procedure TForm1.Button1Click(Sender: TObject);
begin
try
Screen.Cursor := crHourGlass;
label1.Caption := GetPDC('');
finally
Screen.Cursor := crDefault;
end;
end;