Question

声明;我是一个mvc nub。我有点卡住了，就像几天前一样，我不知道为什么现在不行。问题是我没有得到子类数据，只有“普通”属性的数据。我在Global.asax中填充了5行，而表RedayModels在DB中。数据库中的键也可以。

编辑：两个表ReWeekModel和ReDayModel都有数据。我正在使用代码优先方法。

我有这个DB：

public class ReChronoDB : DbContext
{
    public DbSet<ReWeekRowModel> WeekRows { get; set; }        
}

这是我的DbSet行

public class ReWeekRowModel
{
    public ReWeekRowModel()
    {
        CreatedDate = DateTime.Now;
        Days = new List<ReDayModel>()
        {
            new ReDayModel {DayName = DayOfWeek.Monday},
            new ReDayModel {DayName = DayOfWeek.Tuesday},
            new ReDayModel {DayName = DayOfWeek.Wednesday},
            new ReDayModel {DayName = DayOfWeek.Thursday},
            new ReDayModel {DayName = DayOfWeek.Friday},
            new ReDayModel {DayName = DayOfWeek.Saturday},
            new ReDayModel {DayName = DayOfWeek.Sunday}
        };
    }

    public DateTime CreatedDate { get; private set; }
    [Key]
    public int Id { get; set; } 
    public string Name { get; set; } 
    [DisplayName("Week #"), Range(1, 53)]
    public int WeekOfYear { get; set; } 
    [Range(2017,2075)]
    public int Year { get; set; }
    public List<ReDayModel> Days { get; set; } 
    public Priority Priority { get; set; }
    public Status Status { get; set; }
    public Category Category { get; set; } 
    public Responsible Responsible { get; set; }
    public ResponseGroup ResponseGroup { get; set; }
    public string CaseRef { get; set; } 
    [StringLength(75), DisplayName("Short Description")]
    public string Description { get; set; } 
    public string Details { get; set; } 

}

这里是子类：

public class ReDayModel
{
    [Key]
    public int Id { get; set; }
    public DayOfWeek DayName { get; set; }
    public double Hours { get; set; }
    public string Comments { get; set; }
}

最后，这是带有Index Action的控制器。

public class ReChronoController : Controller
{
    ReChronoDB _reChronoDb = new ReChronoDB();

    // GET: ReChrono
    public ActionResult Index(string responsegroup = "", string responsible = "", int week = 0, int year = 0)
    {
        CultureInfo ciCurr = CultureInfo.CurrentCulture;
        ViewBag.CurrentWeek = ciCurr.Calendar.GetWeekOfYear(DateTime.Now, CalendarWeekRule.FirstFourDayWeek,
            DayOfWeek.Monday);
        ViewBag.CurrentYear = ciCurr.Calendar.GetYear(DateTime.Today);


        var model = _reChronoDb.WeekRows.ToList();

        // For dropdownlists
        ViewBag.Years = _reChronoDb.WeekRows.Select(r => r.Year).Distinct();
        ViewBag.Weeks = _reChronoDb.WeekRows.Select(r => r.WeekOfYear).Distinct();

        var filteredmodel = ReChronoDomainLayer.FilteredWeekRows(model, responsegroup, responsible, week, year);

        return View(filteredmodel);
    }
}

当我将鼠标悬停在“model”变量上并向下钻取时，行的Days集合没有值。

编辑：这是正在执行的sql：

SELECT 
[Extent1].[Id] AS [Id], 
[Extent1].[CreatedDate] AS [CreatedDate], 
[Extent1].[Name] AS [Name], 
[Extent1].[WeekOfYear] AS [WeekOfYear], 
[Extent1].[Year] AS [Year], 
[Extent1].[Priority] AS [Priority], 
[Extent1].[Status] AS [Status], 
[Extent1].[Category] AS [Category], 
[Extent1].[Responsible] AS [Responsible], 
[Extent1].[ResponseGroup] AS [ResponseGroup], 
[Extent1].[CaseRef] AS [CaseRef], 
[Extent1].[Description] AS [Description], 
[Extent1].[Details] AS [Details]
FROM [dbo].[ReWeekRowModels] AS [Extent1]

编辑：这是上下文？

public class ReChronoDBInitializer : 
    DropCreateDatabaseIfModelChanges<ReChronoDB>
{
    protected override void Seed(ReChronoDB context)
    {
        base.Seed(context);

        var enumToLookup = new EnumToLookup();

        enumToLookup.Apply(context);

        ReChronoDomainLayer.CreateDummyEntries(context);
    }
}

似乎完全忽略了List Days集合。

我也尝试过没有过滤模型，但我把它放在这里，所以你明白为什么我在动作中有参数。

有什么想法吗？

Answer 1

首先请确保ReDayModel也是ReChronoDB的一部分：

public class ReChronoDB : DbContext
{
    public DbSet<ReWeekRowModel> WeekRows { get; set; }    
    public DbSet<ReDayModel> DayRows { get; set; }    
}

现在您的控制器操作尝试使用延迟加载，但由于Days属性的属性类型不正确而被禁用。如果要启用延迟加载，您的类应如下所示：

public class ReWeekRowModel
{
   ...
   public virtual ICollection<ReDayModel> Days { get; set; }
   ...
}

作为替代方案，您可以使用急切加载，这需要更改您的操作才能使用.Include()方法：

public class ReChronoController : Controller
{
    ...
    public ActionResult Index(string responsegroup = "", string responsible = "", int week = 0, int year = 0)
    {
       ...
       var model = _reChronoDb.WeekRows.Include(w => w.Days).ToList();
       ...
    }
}

如果您始终需要Days集合，则可能会带来更好的性能。请阅读更多here。

asp.net mvc不再从子类获取值

1 个答案: