无法在 ASP.NET MVC 中转换数据初始化程序？

Question

我正在学习教程：http://www.asp.net/mvc/overview/getting-started/getting-started-with-ef-using-mvc/creating-an-entity-framework-data-model-for-an-asp-net-mvc-application。我在 SchoolInitializer.cs 中添加了我的数据，但是，我收到以下错误：

Object of type 'ContosoUniversity.DAL.SchoolInitializer' cannot be converted to type 'System.Data.Entity.IDatabaseInitializer`1[ContosoUniversity.DAL.SchoolContext]'.

Web.config:

<contexts>
      <context type="ContosoUniversity.DAL.SchoolContext, ContosoUniversity">
        <databaseInitializer type="ContosoUniversity.DAL.SchoolInitializer, ContosoUniversity" />
      </context>
</contexts>

SchoolInitializer.cs：本教程声明了 Seed() 覆盖。当我添加 "override" 时，它显示

Error 1 'ContosoUniversity.DAL.SchoolInitializer.Seed(ContosoUniversity.DAL.SchoolContext)': no suitable method found to override

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using ContosoUniversity.Models;

namespace ContosoUniversity.DAL
{
    //When accessing DB initially for every run. If there's a difference between database to the model (SchoolContext, Entity Class)
    //Drops and recreates Database with data in SchoolInitializer

    //In Web.config: add <context> </context> to let Entity Framework use SchoolInitializer 
    public class SchoolInitializer
    {
        protected void Seed(SchoolContext context)
        {
            var students = new List<Student>
            {
                new Student{FirstMidName="Carson",LastName="Alexander",EnrollmentDate=DateTime.Parse("2005-09-01")},
                new Student{FirstMidName="Meredith",LastName="Alonso",EnrollmentDate=DateTime.Parse("2002-09-01")},
                new Student{FirstMidName="Arturo",LastName="Anand",EnrollmentDate=DateTime.Parse("2003-09-01")},
                new Student{FirstMidName="Gytis",LastName="Barzdukas",EnrollmentDate=DateTime.Parse("2002-09-01")},
                new Student{FirstMidName="Yan",LastName="Li",EnrollmentDate=DateTime.Parse("2002-09-01")},
                new Student{FirstMidName="Peggy",LastName="Justice",EnrollmentDate=DateTime.Parse("2001-09-01")},
                new Student{FirstMidName="Laura",LastName="Norman",EnrollmentDate=DateTime.Parse("2003-09-01")},
                new Student{FirstMidName="Nino",LastName="Olivetto",EnrollmentDate=DateTime.Parse("2005-09-01")}
            };

            //Add entities to DbSet (entity set)
            students.ForEach(s => context.Students.Add(s));
            context.SaveChanges();
            var courses = new List<Course>
            {
                new Course{CourseID=1050,Title="Chemistry",Credits=3,},
                new Course{CourseID=4022,Title="Microeconomics",Credits=3,},
                new Course{CourseID=4041,Title="Macroeconomics",Credits=3,},
                new Course{CourseID=1045,Title="Calculus",Credits=4,},
                new Course{CourseID=3141,Title="Trigonometry",Credits=4,},
                new Course{CourseID=2021,Title="Composition",Credits=3,},
                new Course{CourseID=2042,Title="Literature",Credits=4,}
            };
            courses.ForEach(s => context.Courses.Add(s));
            context.SaveChanges();
            var enrollments = new List<Enrollment>
            {
                new Enrollment{StudentID=1,CourseID=1050,Grade=Grade.A},
                new Enrollment{StudentID=1,CourseID=4022,Grade=Grade.C},
                new Enrollment{StudentID=1,CourseID=4041,Grade=Grade.B},
                new Enrollment{StudentID=2,CourseID=1045,Grade=Grade.B},
                new Enrollment{StudentID=2,CourseID=3141,Grade=Grade.F},
                new Enrollment{StudentID=2,CourseID=2021,Grade=Grade.F},
                new Enrollment{StudentID=3,CourseID=1050},
                new Enrollment{StudentID=4,CourseID=1050,},
                new Enrollment{StudentID=4,CourseID=4022,Grade=Grade.F},
                new Enrollment{StudentID=5,CourseID=4041,Grade=Grade.C},
                new Enrollment{StudentID=6,CourseID=1045},
                new Enrollment{StudentID=7,CourseID=3141,Grade=Grade.A},
            };
            enrollments.ForEach(s => context.Enrollments.Add(s));
            context.SaveChanges();
        }
    }
}

Answer 1

替换下一行

public class SchoolInitializer

与

public class SchoolInitializer: DropCreateDatabaseIfModelChanges<SchoolContext>

或与

public class SchoolInitializer: DropCreateDatabaseAlways<SchoolContext>

无法在 ASP.NET MVC 中转换数据初始化程序？

Data Initializer Cannot be converted in ASP.NET MVC?

c#

asp.net

asp.net-mvc

entity-framework