自动映射枚举 Class

Question

我正在尝试使用枚举 classes (link) 而不是枚举和 "lookup tables".

我有这种情况，它在我的视图中显示一个简单的列表，我想在其中显示枚举 class 中的 TaskStatus 名称而不是 StatusId，但我收到此错误 "InvalidOperationException: The entity type 'TaskStatus' requires a primary key to be defined."

难道我的做法全错了吗？

<table clss="table">
    @foreach(var item in Model)
    {
        <tr>
            <td>@item.Id</td>
            <td>@item.Name</td>
            <td>@item.Status</td>
        </tr>
    }
</table>

public class Tasks : BaseEntity
{
    public string Name { get; set; }
    public DateTime? StartDate { get; set; }
    public DateTime? DueDate { get; set; }
    public byte StatusId { get; set; }
    public string AssignedTo { get; set; }

    public virtual TaskStatus Status { get; set; }
}

public class IndexVm
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime? StartDate { get; set; }
    public DateTime? DueDate { get; set; }
    public byte StatusId { get; set; }

    public TaskStatus Status { get; set; } 
}

public class TaskStatus : Enumeration<TaskStatus, int>
{
    public static readonly TaskStatus NotStarted           = new TaskStatus(1, "Not Started");
    public static readonly TaskStatus InProgress           = new TaskStatus(2, "In Progress");
    public static readonly TaskStatus Completed            = new TaskStatus(3, "Completed");
    public static readonly TaskStatus WaitingOnSomeoneElse = new TaskStatus(4, "Waiting on someone else");
    public static readonly TaskStatus Deferred             = new TaskStatus(5, "Deferred");

private TaskStatus(int value, string displayName) : base(value, displayName) { }
}

public class MappingProfile : Profile
{
    public MappingProfile()
    {
        CreateMap<Tasks, IndexVm>()
            .ForMember(vm => vm.Status, conf => conf.MapFrom(ol => ol.Status.DisplayName));
    }
}

Answer 1

您的问题与Automapper无关。您收到的错误消息来自 EntityFramework。因为您在实体中定义了 Status 属性，所以 EF 试图将 TaskStatus class 视为另一个实体，但它不能，因为它没有主键作为错误消息状态。

如果您对使用 Enum 死心塌地 class请看一下标题 "Encapsulated primitives (aka the NodaTime/Enumeration class problem)"

下的 here

尝试将您的代码更改为如下内容：

public class IndexVm
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime? StartDate { get; set; }
    public DateTime? DueDate { get; set; }
    public byte StatusId { get; set; }

    [NotMapped]
    public TaskStatus Status { 
        get { //Return the value of StatusVal converted to an Enumeration 
        set { //Set the value of StatusVal after converting from an Enumeration } 
    } 
    public int StatusVal { get; set; }
}

自动映射枚举 Class

AutoMapping Enumeration Class

enumeration

automapper