Question

我尝试使用枚举类（link）代替枚举和＆＃34;查找表＆＃34;。

我有这个场景，在我的视图中显示一个简单的列表，我想在枚举类而不是StatusId中显示TaskStatus名称，但是我得到了这个错误＆＃34; InvalidOperationException：实体类型＆＃39; TaskStatus＆＃39;需要定义主键。＆＃34;

我的方法是不是错了？

<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正在尝试将TaskStatus类视为另一个实体而不能，因为它没有主键，因为错误消息指出。

如果您已经设置使用Enum类，请在标题＆＃34; Encapsulated primitives（又名NodaTime / Enumeration类问题）＆＃34;

标题下查看here。

尝试将代码更改为以下内容：

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; }
}

AutoMapping枚举类

1 个答案: