Asp.net mvc 在控制器内正确处理存储库对象
我很难弄明白这一点。我已经实现了存储库和工作单元模式,作为数据库的数据访问抽象。我使用依赖注入将它们注入控制器。问题是当控制器被释放时,它会释放存储库,但当我刷新页面时,存储库中的DbContext对象为null(我认为不应该为null)。类的实现如下所示 这是数据库存储库类:Asp.net mvc 在控制器内正确处理存储库对象,asp.net-mvc,dependency-injection,repository-pattern,dispose,Asp.net Mvc,Dependency Injection,Repository Pattern,Dispose,我很难弄明白这一点。我已经实现了存储库和工作单元模式,作为数据库的数据访问抽象。我使用依赖注入将它们注入控制器。问题是当控制器被释放时,它会释放存储库,但当我刷新页面时,存储库中的DbContext对象为null(我认为不应该为null)。类的实现如下所示 这是数据库存储库类: public class ConferenceCrawlyDbRepository : IConferenceCrawlyDbRepository { private ConferenceCrawlyDbCont
public class ConferenceCrawlyDbRepository : IConferenceCrawlyDbRepository
{
private ConferenceCrawlyDbContext _context = null;
private static ConferenceCrawlyDbRepository _instance = null;
public IRepository<AcademicDegree> AcademicDegrees { get; private set; }
public IRepository<Conference> Conferences { get; private set; }
public IRepository<ConferenceComment> ConferenceComments { get; private set; }
public IRepository<ConferenceRating> ConferenceRatings { get; private set; }
public IRepository<ConnectionConferenceRecommendation> ConnectionConferenceRecommendation { get; private set; }
public IRepository<Country> Countries { get; private set; }
public IRepository<ImportantDate> ImportantDates { get; private set; }
public IRepository<Topic> Topics { get; private set; }
public IRepository<UserProfile> UserProfiles { get; private set; }
public IRepository<UserProfileSettings> UserProfileSettings { get; private set; }
public IRepository<UsersConnection> UserConnections { get; private set; }
public IRepository<Venue> Venues { get; private set; }
private ConferenceCrawlyDbRepository(ConferenceCrawlyDbContext context)
{
_context = context;
AcademicDegrees = new Repository<AcademicDegree>(context);
Conferences = new Repository<Conference>(context);
ConferenceComments = new Repository<ConferenceComment>(context);
ConferenceRatings = new Repository<ConferenceRating>(context);
ConnectionConferenceRecommendation = new Repository<ConnectionConferenceRecommendation>(context);
Countries = new Repository<Country>(context);
ImportantDates = new Repository<ImportantDate>(context);
Topics = new Repository<Topic>(context);
UserProfiles = new Repository<UserProfile>(context);
UserProfileSettings = new Repository<UserProfileSettings>(context);
UserConnections = new Repository<UsersConnection>(context);
Venues = new Repository<Venue>(context);
}
public static ConferenceCrawlyDbRepository Instance
{
get
{
if (_instance == null)
_instance = new ConferenceCrawlyDbRepository(new ConferenceCrawlyDbContext());
return _instance;
}
}
public bool CommitChanges()
{
try
{
return _context.SaveChanges() > 0;
}
catch
{
// TODO: Add logging
return false;
}
}
public void Dispose()
{
if (_context != null)
_context.Dispose();
}
public class Repository<TEntity> : IRepository<TEntity> where TEntity : class
{
private ConferenceCrawlyDbContext _context = null;
private DbSet<TEntity> _dbSet = null;
public Repository(ConferenceCrawlyDbContext context)
{
_context = context;
_dbSet = context.Set<TEntity>();
}
public DbSet<TEntity> DbSet
{
get
{
return _dbSet;
}
}
public bool Add(TEntity entity)
{
try
{
DbSet.Add(entity);
return true;
}
catch (Exception ex)
{
// TODO: Add logging
return false;
}
}
public bool Update(TEntity entity)
{
try
{
var entry = _context.Entry<TEntity>(entity);
DbSet.Attach(entity);
entry.State = EntityState.Modified;
return true;
}
catch(Exception ex)
{
// TODO: Add logging
return false;
}
}
public bool Remove(TEntity entity)
{
try
{
DbSet.Remove(entity);
return true;
}
catch (Exception ex)
{
// TODO: Add logging
return false;
}
}
public IQueryable<TEntity> GetAll()
{
return DbSet;
}
public IQueryable<TEntity> Find(Expression<Func<TEntity, bool>> predicate)
{
return DbSet.Where(predicate);
}
public TEntity FindById(params object[] keys)
{
return DbSet.Find(keys);
}
public bool Contains(Expression<Func<TEntity, bool>> predicate)
{
return _dbSet.Any(predicate);
}
public bool CommitChanges()
{
try
{
return _context.SaveChanges() > 0;
}
catch
{
// TODO: Add logging
return false;
}
}
public void Dispose()
{
if (_context != null)
_context.Dispose();
}
}
最后,控制器及其动作:
public class HomeController : Controller
{
private IConferenceCrawlyDbRepository _dbRepository;
private IMailService _mailService;
public HomeController(IConferenceCrawlyDbRepository dbRepository, IMailService mailService)
{
_dbRepository = dbRepository;
_mailService = mailService;
}
//
// GET: /
public ActionResult Index()
{
var countries = _dbRepository.Countries.GetAll().ToList();
return View(countries);
}
//
// GET: /Home/About
public ActionResult About()
{
return View();
}
//
// GET: /Home/Contact
public ActionResult Contact()
{
return View(new Contact());
}
//
// POST: /Home/Contact
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Contact(Contact contact)
{
if (ModelState.IsValid)
{
if (await _mailService.SendMail(contact.Email, contact.Title,
String.Format("{1}{0}{2}", Environment.NewLine, contact.Message, String.IsNullOrEmpty(contact.Name) ? "Anonimous" : contact.Name)))
{
ViewBag.SuccessMessage = "Comment has been successfully sent.";
return View(new Contact());
}
else
ViewBag.ErrorMessage = "Couldn't send your email. Please try again later";
}
return View(contact);
}
protected override void Dispose(bool disposing)
{
if (_dbRepository != null)
_dbRepository.Dispose();
base.Dispose(disposing);
}
}
公共类HomeController:控制器
{
私有IConferenceCrawlyDbRepository\u dbRepository;
私人iMail服务(邮递服务),;
公共HomeController(IConferenceCrawlyDbRepository,iMail服务邮件服务)
{
_dbRepository=dbRepository;
_mailService=mailService;
}
//
//获取:/
公共行动结果索引()
{
var countries=_dbRepository.countries.GetAll().ToList();
返回视图(国家);
}
//
//到家/大约
关于()的公共行动结果
{
返回视图();
}
//
//取得/回家/联系
公共行动结果联系人()
{
返回视图(新联系人());
}
//
//职位:/Home/联系人
[HttpPost]
[ValidateAntiForgeryToken]
公共异步任务联系人(联系人联系人)
{
if(ModelState.IsValid)
{
如果(等待)mailService.SendMail(contact.Email,contact.Title,
String.Format(“{1}{0}{2}”、Environment.NewLine、contact.Message、String.IsNullOrEmpty(contact.Name)?“Anonimous”:contact.Name)))
{
ViewBag.SuccessMessage=“评论已成功发送。”;
返回视图(新联系人());
}
其他的
ViewBag.ErrorMessage=“无法发送您的电子邮件。请稍后再试”;
}
返回视图(联系人);
}
受保护的覆盖无效处置(布尔处置)
{
if(_dbRepository!=null)
_dbRepository.Dispose();
基地。处置(处置);
}
}
当我调用存储库时,异常会在索引操作中抛出,但只有在第一次访问此控制器并且它表示存储库中的DbContext对象之后才会抛出。很明显,我做错了什么,但我想不出来。我在长时间的启动和调试代码后才发现。这很简单,因为我在ConferenceScrawlyDBRepository中处理上下文,我还应该将使用它的_实例对象设置为null,然后它将与DbContext对象一起重新创建。我现在觉得自己太蠢了…你不能在GetControllerInstance中设置一个调试点并跟踪它吗?我设置了,但这对我没有帮助。正如我所说,它很好地处理了它,但是当第二次调用它时,上下文是空的。这没有意义,因为我正在调用实例,如果该实例为空,则该实例应创建新上下文。该存储库是一个令人讨厌的对象。与直接使用EF相比,它没有增加任何价值。你为什么要用它?
public class HomeController : Controller
{
private IConferenceCrawlyDbRepository _dbRepository;
private IMailService _mailService;
public HomeController(IConferenceCrawlyDbRepository dbRepository, IMailService mailService)
{
_dbRepository = dbRepository;
_mailService = mailService;
}
//
// GET: /
public ActionResult Index()
{
var countries = _dbRepository.Countries.GetAll().ToList();
return View(countries);
}
//
// GET: /Home/About
public ActionResult About()
{
return View();
}
//
// GET: /Home/Contact
public ActionResult Contact()
{
return View(new Contact());
}
//
// POST: /Home/Contact
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Contact(Contact contact)
{
if (ModelState.IsValid)
{
if (await _mailService.SendMail(contact.Email, contact.Title,
String.Format("{1}{0}{2}", Environment.NewLine, contact.Message, String.IsNullOrEmpty(contact.Name) ? "Anonimous" : contact.Name)))
{
ViewBag.SuccessMessage = "Comment has been successfully sent.";
return View(new Contact());
}
else
ViewBag.ErrorMessage = "Couldn't send your email. Please try again later";
}
return View(contact);
}
protected override void Dispose(bool disposing)
{
if (_dbRepository != null)
_dbRepository.Dispose();
base.Dispose(disposing);
}
}