堆栈溢出问题，Asp.net MVC

Question

我在公共场合收到“System.StackOverflowException 未处理”

VolunteerDBEntities() : base("name=VolunteerDBEntities", "VolunteerDBEntities")
        {
            OnContextCreated();
        }

当我更改此内容时会发生这种情况：

   public class OrganizationService : IOrganizationService
    {

        private IValidationDictionary _validationDictionary;
        private IOrganizationRepository _repository;

        public OrganizationService(IValidationDictionary validationDictionary)
            : this(validationDictionary, new OrganizationRepository())
        { }


        public OrganizationService(IValidationDictionary validationDictionary, IOrganizationRepository repository)
        {
            _validationDictionary = validationDictionary;
            _repository = repository;
        }
...}

对此：

public class OrganizationService : IOrganizationService
    {

        private IValidationDictionary _validationDictionary;
        private IOrganizationRepository _repository;
        private ISessionService _session;

        public OrganizationService(IValidationDictionary validationDictionary)
            : this(validationDictionary, new OrganizationRepository(), new SessionService())
        { }


        public OrganizationService(IValidationDictionary validationDictionary, IOrganizationRepository repository, ISessionService session)
        {
            _validationDictionary = validationDictionary;
            _repository = repository;
            _session = session;
        }
...}

我对此一无所知。我将其设置为单元测试，每当我向该服务添加类变量时，它就会崩溃。我可以将类变量添加到另一个服务中，或者创建一个复制该类变量但减去接口的服务，并且它可以工作。有什么想法吗？

会话服务构造：

   public class SessionService: ISessionService 
    {
        private IMembershipService _membershipService;
        private IVolunteerService _volunteerService;
        private IMessageService _messageService;

          public SessionService() 
            : this(new AccountMembershipService(null), new VolunteerService(null), new MessageService())
        {}


          public SessionService(IMembershipService membershipservice, IVolunteerService volunteerservice, IMessageService messageservice)
        {
            _membershipService = membershipservice;
            _volunteerService = volunteerservice;
            _messageService = messageservice;
        }

其他服务构造：

private IValidationDictionary _validationDictionary; 私人 IVolunteerRepository _repository; 私有 IOrganizationService _orgservice；

public VolunteerService(IValidationDictionary validationDictionary) 
    : this(validationDictionary, new VolunteerRepository(), new OrganizationService(null))
{}


public VolunteerService(IValidationDictionary validationDictionary, IVolunteerRepository repository, IOrganizationService orgservice)
{
    _validationDictionary = validationDictionary;
    _repository = repository;
    _orgservice = orgservice;

}



public class AccountMembershipService : IMembershipService
{
    private readonly System.Web.Security.MembershipProvider _provider;
    private IValidationDictionary _validationDictionary;
    private IVolunteerService _volservice;
    private IEmailService _emailservice;

    public AccountMembershipService(IValidationDictionary validationDictionary)
        : this(validationDictionary, null, new VolunteerService(null), new EmailService())
    {
    }

   public AccountMembershipService(IValidationDictionary validationDictionary, System.Web.Security.MembershipProvider provider, VolunteerService volservice, EmailService emailservice )
    {
        _validationDictionary = validationDictionary;
        _provider = provider ?? Membership.Provider;
       _volservice = volservice;
       _emailservice = emailservice;
    }

Answer 1

您正在递归地创建对象集。

您的代码“闻起来”带有生产中的测试逻辑，因为您隐式创建了所有对象。

相反，我鼓励使用依赖注入或其他解决方案，这样你就不会在你的构造函数。

在最坏情况中，只需使用ServiceLocator模式。

最后一个选项对您来说是最简单的方法，因为您已经有太多的东西绑定在一起。您的代码如下所示：

   public class OrganizationService : IOrganizationService
    {

        private IValidationDictionary _validationDictionary;
        private IOrganizationRepository _repository;

        public OrganizationService() {
            _validationDictionary = ServiceLocator.Get<IValidationDictionary>();
            _repository = ServiceLocator.Get<IOrganizationRepository>();
        }
    }

让我们在此处查看对 IOrganizationRepository 的依赖关系。

我们不需要知道它的确切类型。所以我们不在乎。 ServiceLocator 是唯一关心的主体。

通常它只是一个静态类（但请记住多线程和同步！）。

它可以像这样实现（我不想指出现有的实现，因为它太简单了）：

public static class ServiceLocator {
    static Func<T, object> _resolver;

    public static Setup(Func<T, object> resolver) {
        _resolver = resolver;
    }

    public static TService Get<TService>() {
        if (_resolver == null) throw InvalidOperationException("Please Setup first.");
        return (TService)_resolver.Invoke(typeof(TService));
    }
}

然后在您的测试设置中（可能在基本测试类上）只需执行以下操作：

ServiceLocator.Setup(what => {
    if (what == typeof(IOrganizationRepository))
        return organisationRepository = organisationRepository ?? new OrganizationRepository(); // Singleton
    throw new NotSupportedException("The service cannot be resolved: " + what.Name);
});

在生产中您将实例化它不同。

当然，使用 CastleWindsor、Microsoft Unity 或其他依赖注入框架会更容易。

希望这会有所帮助。