端口转发利用“HNetCfg.NATUPnP” OLE对象失败(Port Forwarding by

我使用的是代码为转发的端口。此代码的工作在我的Windows 7罚款; 但我不能在Windows XP上使用它。

更新1对于问题（二零一二年十月十七日07：32：00Z）

这是我的源代码：

uses
  ActiveX, oleAuto;

Procedure AddUPnPEntry(Port: Integer; const Name: ShortString; LAN_IP: string);
Var
  Nat: Variant;
  Ports: Variant;
  SavedCW: Word;
Begin
  if NOT(LAN_IP = '127.0.0.1') then
  begin
    try
      Nat := CreateOleObject('HNetCfg.NATUPnP');
      Ports := Nat.StaticPortMappingCollection;

      // Error Raized From Here!!!
      ShowMessage(inttostr(Ports.count));

      Ports.Add(Port, 'TCP', Port, LAN_IP, True, name);
    except
      ShowMessage('An Error occured with adding UPnP Ports. The ' + name +
        ' port was not added to the router. Please check to see if  your ' +
        'router supports UPnP and has it enabled or disable UPnP.');
    end;
  end;
End;

procedure TForm1.Button2Click(Sender: TObject);
begin
  AddUPnPEntry(1234, 'Hello3', '192.168.1.1');
end;

OFF错误信息：

Project Project1.exe raised exception class $C0000005 with message 'access violation at 0x00504876: read of address 0x00000000'.

Answer 1:

如果您收到一个访问冲突，当您访问计数属性，这意味着该IStaticPortMappingCollection通过返回的接口IUPnPNAT.get_StaticPortMappingCollection方法是nil ，这可以通过您的设备不支持UPnP很多原因造成的，该UPnP是不在设备上启用所述的UPnP用户界面没有安装/活性，等等。

无论如何，以防止此类异常（访问冲突），则必须检查由属性或方法的返回值之前使用它，在这种情况下，你可以使用VarIsClear功能如下所示：

try
  Nat := CreateOleObject('HNetCfg.NATUPnP');
  Ports := Nat.StaticPortMappingCollection;

  if not VarIsClear(Ports) then
  begin
    //do something
    ShowMessage(inttostr(Ports.count));
    Ports.Add(Port, 'TCP', Port, LAN_IP, True, name);
  end;

except on E:Exception do
  ShowMessage('An Error occured with adding UPnP Ports. '+E.Message);
end;

Answer 2:

对于任谁看到这一点，UPnP功能是XP不同，这里是我使用：

TWindowsName = ( WINXP, WINVISTA, WIN7, WIN80, WIN81 );

var
  fWindowsName : TWindowsName;

procedure InitializeWindowsName;
var
  WinVersion  : TOSVersionInfo;

begin

  WinVersion.dwOSVersionInfoSize := sizeof ( WinVersion );
  GetVersionEx ( WinVersion );

  if WinVersion.dwMajorVersion = 5 then
    fWindowsName := WINXP    
  else if WinVersion.dwMajorVersion = 6 then
    fWindowsName := TWindowsName ( WinVersion.dwMinorVersion + 1 );

end;

procedure AddPortThroughUPnP ( const APort: WORD; const AProtocol, ALocalIP, AName: String );
var
  NAT      : Variant;
  Profile  : Variant;
  Ports    : Variant;
  Protocol : Integer;

begin

  if not fEnableUPnP then exit;

  if fWindowsName = WINXP then
  begin

    NAT      := CreateOleObject ( 'HNetCfg.FwMgr' );
    Profile  := NAT.LocalPolicy.CurrentProfile;

    if not VarIsClear ( Profile ) then
    begin

      if AProtocol = 'UDP' then Protocol := 17
      else if AProtocol = 'TCP' then Protocol := 35; 

      Ports          := CreateOLEObject('HNetCfg.FWOpenPort');
      Ports.Name     := AName;
      Ports.Port     := APort;
      Ports.Scope    := 0;
      Ports.Protocol := Protocol;
      Ports.Enabled  := True;

      Profile.GloballyOpenPorts.Add ( Ports );

    end;

  end
  else
  begin

    NAT   := CreateOleObject ( 'HNetCfg.NATUPnP' );
    Ports := NAT.StaticPortMappingCollection;

    if not VarIsClear ( Ports ) then
       Ports.Add ( APort, AProtocol, APort, ALocalIP, True, AName );

  end;

end;

人们可以跳过Windows名称的初始化，并把自己的检查算法来代替。