IIS中与数据服务器的连接失败

Question

我在asp.net-mvc-4中开发了一个网站Visual Studio-2010，该网站从位于其他位置的另一个SQL数据服务器获取数据。我使用端口443进行连接和用户登录以获取数据。网站在调试模式下工作正常，它从数据服务器中提取数据但是当我通过windows IIS上传网站时，它不会与数据服务器建立任何连接，因此无法获取数据。它失败了

 if (c.TryLogOn(AccountData.LogInUserName, AccountData.PW))

完整的方法是

 try {
            using (Client c = AccountData.c)
            //using (TcpClient c = new TcpClient())                       
            {

                if (c.TryLogOn(AccountData.LogInUserName, AccountData.PW))
                {
                    imc.Search.Base.Query.Query q = new imc.Search.Base.Query.Query();

                    AddAttributeListForFahrzeug(q);

                    AttributeValuesCollection values = c.FindInstances(q);

                    if (tempVehicleType == "all")
                    {
                        foreach (object[] av in values)
                        {
                            Fahrzeug d = NewFahrzeug(av);
                            d.VehicleType = tempVehicleType;
                            returnValue.Add(d);
                        }
                    }
                    else
                    {
                        foreach (object[] av in values)
                        {
                            Fahrzeug d = NewFahrzeug(av);
                            if (d.FzgBeschreibung == tempVehicleType)
                            {
                                d.VehicleType = tempVehicleType;
                                returnValue.Add(d);
                            }
                            //d.VehicleType = tempVehicleType;

                        }
                    }
                    c.LogOff();
                }
            }
        } catch ( Exception ){
        }

与客户的连接

static public AccountSettings GetAccountData()
    {
        AccountSettings AccountData = new AccountSettings();
        System.Security.SecureString Pw = new System.Security.SecureString();


        string PwWord = "**********";            
        string LogInUserName = "username";
        foreach (char ch in PwWord)
        {
            Pw.AppendChar(ch);
        }

        //AccountData.c = new Client("abc.xyz.zhg.com", 443, true, ConnectionMode.Internet);
        AccountData.c = new Client("abc.xyz.zhg.com", 1199, false, ConnectionMode.Remote);

        AccountData.PW = Pw;
        AccountData.LogInUserName = LogInUserName;

        return (AccountData);

    }

然后

 AccountSettings AccountData = GetAccountData();