c# - 试图搭建一个 View ，我得到 "unable to retrieve Metadata for"和 'validation error' 'entity type has no key defined'

Question

我有一个程序，我试图找出我的 friend 没有得到的问题。我正在尝试从我的 Controller 搭建一个 View ，我得到了一个

error "Unable to retrieve metadata for 'GradedWork.Controllers.CourseAddForm'. 
One or more validation errors were detected during model generation: 

GradedWork.Model.CourseAddForm : EntityType 'CourseAddForm' has no key defined. Define the 
key for this EntityType. CourseAddForm: EntityType: EntitySet 'CourseAddForm' is based on 
type 'CourseAddForm' that has no keys defined.'

我正在尝试使用 CourseAddForm View 模型类构建一个创建 View ，但我总是遇到此错误。

我的 CourseAddForm 类不应该带有关键字段，我的 friend 没有我遇到的这个问题。

我的 View 模型类:

namespace GradedWork.Controllers
{
public class CourseList
{
    [Key]
    public int Id { get; set; }

    [Display(Name = "Name")]
    public string Name { get; set; }

}

public class CourseAddForm
{


    [Display(Name = "Course Code")]
    public int CourseCode { get; set; }

    // [Required]
    [Display(Name = "Name")]
    public string Name { get; set; }

    //  [Required]
    [Display(Name = "Semester")]
    public string Semester { get; set; }

    // [Required]
    [Display(Name = "Section Id")]
    public string SectionId { get; set; }

    [Display(Name = "Teacher")]
    public ICollection<TeacherList> Teacher { get; set; }

    [Display(Name = "Student")]
    public ICollection<StudentList> Students { get; set; }

    [Display(Name = "Graded Works")]
    public ICollection<GradedWorkList> GradedWorks { get; set; }


    public CourseAddForm()
    {
        this.Teacher = new List<TeacherList>();
        this.Students = new List<StudentList>();
        this.GradedWorks = new List<GradedWorkList>();

    }

}

public class CourseAdd
{

    [Display(Name = "Course Code")]
    public int CourseCode { get; set; }

    // [Required]
    [Display(Name = "Name")]
    public string Name { get; set; }

    //  [Required]
    [Display(Name = "Semester")]
    public string Semester { get; set; }

    // [Required]
    [Display(Name = "Section Id")]
    public string SectionId { get; set; }

    [Display(Name = "Teacher")]
    public ICollection<Teacher> Teacher { get; set; }

    [Display(Name = "Student")]
    public ICollection<Student> Students { get; set; }

    [Display(Name = "Graded Works")]
    public ICollection<GradedWorks> GradedWorks { get; set; }


    public CourseAdd()
    {
        this.Teacher = new List<Teacher>();
        this.Students = new List<Student>();
        this.GradedWorks = new List<GradedWorks>();

    }

}

public class CourseBase : CourseAdd
{
    [Key]
    public int Id { get; set; }

}
}

我正在尝试搭建的 Controller 方法

public ActionResult Create()
    {
        var addForm = new CourseAddForm();

        foreach (var item in m.GetAllTeachersAsList())
        {
            addForm.Teacher.Add(item);
        }

        foreach (var item in m.GetAllStudentsAsList())
        {
            addForm.Students.Add(item);
        }

        foreach (var item in m.GetAllGradedWorkAsList())
        {
            addForm.GradedWorks.Add(item);
        }

        return View(addForm);
    }

    //
    // POST: /Course/Create
    [HttpPost]
    public ActionResult Create(CourseAdd newItem)
    {
        if (ModelState.IsValid)
        {

            var addedItem = m.AddCourse(newItem);

            if (addedItem == null)
            {
                return RedirectToAction("Index");
            }

            else
            {
                return RedirectToAction("Details", new { id = addedItem.Id });
            }


        }

        else
        {
            var addForm = Mapper.Map<CourseAddForm>(newItem);

            foreach (var item in m.GetAllTeachersAsList())
            {
                addForm.Teacher.Add(item);
            }

            foreach (var item in m.GetAllStudentsAsList())
            {
                addForm.Students.Add(item);
            }

            foreach (var item in m.GetAllGradedWorkAsList())
            {
                addForm.GradedWorks.Add(item);
            }

            return View(addForm);
        }
    }

我的连接字符串:

<connectionStrings>
<add name="DataContext" connectionString="Data Source=(LocalDb)\v11.0;AttachDbFilename=|DataDirectory|\StoreName.mdf;Initial Catalog=StoreName;Integrated Security=True" providerName="System.Data.SqlClient" />

Answer 1

我所要做的就是删除脚手架中的 datacontext 选项，它就可以工作了......