不支持LINQ到实体

Question

我试图用控制器列出一些食品项目。我对另一个程序集中的数据使用UnitOfWork的存储库模式，并在BaseApiController中引用它。Data属性是我的UnitOfWork实例。

var result = Data.Food
            .FindAll()
            .Select(FoodItemViewModel.Create);
return result;

这里是我的ViewModel:

public static Expression<Func<FoodItem, FoodItemViewModel>> Create
    {
        get
        {
            return fi => new FoodItemViewModel
            {
                Id = fi.Id,
                Description = fi.Description,
                DiaryEntries = fi.DiaryEntries
                .Select(s => new DiaryEntityViewModel()
                {
                    Id = s.Id,
                    Quantity = s.Quantity
                }
            };
        }
    }

但我得到的是:

"在LINQ to中不支持指定的类型成员'DiaryEntries'实体。只有初始化式、实体成员和实体导航支持属性。"

My DiaryEntries成员在ViewModel是

IEnumerable<DiaryEntityViewModel>

，并且我的Data实例中的DiaryEntries成员是

IRepository<DiaryEntry>

和DiaryEntry是我的模型类

下面是我的FoodItem模型类:

public class FoodItem
    {
        private IEnumerable<Measure> measures;
        private IEnumerable<DiaryEntry> diaryEntries;
        public FoodItem()
        {
            this.measures = new HashSet<Measure>();
            this.diaryEntries = new HashSet<DiaryEntry>();
        }
        public int Id { get; set; }
        public string Description { get; set; }
        public virtual IEnumerable<DiaryEntry> DiaryEntries
        {
            get
            {
                return this.diaryEntries;
            }
            set
            {
                this.diaryEntries = value;
            }
        }
        public virtual IEnumerable<Measure> Measures
        {
            get
            {
                return this.measures;
            }
            set
            {
                this.measures = value;
            }
        }
    }

Answer 1

将您的FoodItem类更改为下面的类型， IEnumerable<T>不支持作为导航集合的类型:

public class FoodItem
{
    public FoodItem()
    {
        this.Measures = new HashSet<Measure>();
        this.DiaryEntries = new HashSet<DiaryEntry>();
    }
    public int Id { get; set; }
    public string Description { get; set; }
    public virtual ICollection<DiaryEntry> DiaryEntries
    {
        get;
        set;
    }
    public virtual ICollection<Measure> Measures
    {
        get;
        set;
    }
}