How to get fully qualified domain name on Windows in Delphi

问题

I need to get a fully qualified domain name for a Windows machine on a domain in Delphi.

I've tried to use LookupAccountSid but it gives me only the netbios domain name, in my case it is "intranet" but I need the full "intranet.companyname.com"

Any Ideas?

回答1:

Try the GetUserNameEx Windows API function.

const
  NameUnknown            = 0;
  NameFullyQualifiedDN   = 1;
  NameSamCompatible      = 2;
  NameDisplay            = 3;
  NameUniqueId           = 6;
  NameCanonical          = 7;
  NameUserPrincipal      = 8;
  NameCanonicalEx        = 9;
  NameServicePrincipal   = 10;
  NameDnsDomain          = 12;

function GetUserNameExString(ANameFormat: DWORD): string;
var
  Buf: array[0..256] of Char;
  BufSize: DWORD;
  GetUserNameEx: function (NameFormat: DWORD; lpNameBuffer: LPSTR;
    var nSize: ULONG): BOOL; stdcall;
begin
  Result := '';
  BufSize := SizeOf(Buf) div SizeOf(Buf[0]);
  GetUserNameEx := GetProcAddress(GetModuleHandle('secur32.dll'), 'GetUserNameExA');
  if Assigned(GetUserNameEx) then
    if GetUserNameEx(ANameFormat, Buf, BufSize) then
      Result := Buf;
end;

using the NameDnsDomain format for example, will result www.mydomain.com\user_name if you are logged into "www.mydomain.com" domain.

Since I now implemented this for my own needs in our application, @iPath's comment was quit right. better use GetComputerNameEx, and specify one of the COMPUTER_NAME_FORMAT for your own needs.

A Delphi implementation would look like this (Unicode version):

interface
...
type
  COMPUTER_NAME_FORMAT = (
    ComputerNameNetBIOS,
    ComputerNameDnsHostname,
    ComputerNameDnsDomain,
    ComputerNameDnsFullyQualified,
    ComputerNamePhysicalNetBIOS,
    ComputerNamePhysicalDnsHostname,
    ComputerNamePhysicalDnsDomain,
    ComputerNamePhysicalDnsFullyQualified,
    ComputerNameMax);

function GetComputerNameExString(ANameFormat: COMPUTER_NAME_FORMAT): WideString;

implementation
...
function GetComputerNameExW(NameType: COMPUTER_NAME_FORMAT; lpBuffer: LPWSTR;
  var nSize: DWORD): BOOL; stdcall; external kernel32 name 'GetComputerNameExW';

function GetComputerNameExString(ANameFormat: COMPUTER_NAME_FORMAT): WideString;
var
  nSize: DWORD;
begin
  nSize := 1024;
  SetLength(Result, nSize);
  if GetComputerNameExW(ANameFormat, PWideChar(Result), nSize) then
    SetLength(Result, nSize)
  else
    Result := '';
end;

回答2:

NetGetJoinInformation should work fine.

MSDN:

http://msdn.microsoft.com/en-us/library/windows/desktop/aa370423(v=vs.85).aspx

Example:

type
  PWKSTA_INFO_100 = ^WKSTA_INFO_100;

  WKSTA_INFO_100 = packed record
    wki100_platform_id: DWord;
    wki100_computername: PWChar;
    wki100_langroup: PWChar;
    wki100_ver_major: DWord;
    wki100_ver_minor: DWord;
  end;

  TNetSetupJoinStatus =
  (
    NetSetupUnknownStatus,
    NetSetupUnjoined,
    NetSetupWorkgroupName,
    NetSetupDomainName
  );

  TNetApiBufferFreeFunction = function(ABuffer: Pointer): DWORD; stdcall;
  TNetWkstaGetInfoFunction  = function(const AServername: PWChar; const ALevel: DWord; const ABufptr: Pointer): DWORD; stdcall;
  TNetGetJoinInformationFunction = function(const AServerName: PWChar; out ANameBuffer: PWChar; out ABufferType: TNetSetupJoinStatus): DWORD; stdcall;

const
  NERR_SUCCESS = 0;

function GetLocalComputerDomainName: string;
var
  NetApiBuffer: Pointer;
  NetApi: THandle;
  NetApiBufferFree: TNetApiBufferFreeFunction;
  NetWkstaGetInfo: TNetWkstaGetInfoFunction;
  NetGetJoinInformation: TNetGetJoinInformationFunction;
  NetSetupJoinStatus: TNetSetupJoinStatus;
  NameBuffer: PWideChar;
begin
  Result := '';
  NetApi := LoadLibrary('netapi32.dll');
  if NetApi <> 0 then
  begin
    NetApiBufferFree      := TNetApiBufferFreeFunction(     GetProcAddress(NetApi, 'NetApiBufferFree'));
    NetGetJoinInformation := TNetGetJoinInformationFunction(GetProcAddress(NetApi, 'NetGetJoinInformation'));
    NetWkstaGetInfo       := TNetWkstaGetInfoFunction(      GetProcAddress(NetApi, 'NetWkstaGetInfo'));
    if @NetApiBufferFree <> nil then
    begin
      if @NetSetupJoinStatus <> nil then
      begin
        if NetGetJoinInformation(nil, NameBuffer, NetSetupJoinStatus) = NERR_SUCCESS then
        begin
          if NetSetupJoinStatus = NetSetupDomainName then
          begin
            Result := NameBuffer;
          end;
          NetApiBufferFree(NameBuffer);
        end;
      end;
    end;
    FreeLibrary(NetApi);
  end;
end;

回答3:

I tried all of the above, but without success. In the end, I settled for simply grabbing the environment variable.

uses jclSysInfo;

function GetDomain:string;
begin
     result:=GetEnvironmentVariable('USERDNSDOMAIN');
end;

Tested on Server 2008 R2 - works fine. Returns "server.home.lan". Results in an empty string on a Windows 7 non-domain connected PC.

回答4:

The only correct api to use is DsGetDcName. Because NetGetJoinInformation is still from the 'lanmanager age' so, the domain is LM compliant.

The code here is C, but you are smart enough to do the same in Delphi :)

PDOMAIN_CONTROLLER_INFOW pdomInfo ;
auto result1 = ::DsGetDcNameW(nullptr, nullptr, nullptr, nullptr, DS_DIRECTORY_SERVICE_PREFERRED | DS_RETURN_DNS_NAME, &pdomInfo);
if (result1 == ERROR_SUCCESS) {
auto retVal = SysAllocString(pdomInfo->DomainName);
                ::NetApiBufferFree(pdomInfo);
}

来源：https://stackoverflow.com/questions/8446940/how-to-get-fully-qualified-domain-name-on-windows-in-delphi

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