c# - 将 ASPNET MVC RC1 迁移到 RC2 后出现 Entity Framework Core 错误

Question

我正在按照以下视频和帖子将我的应用程序从 ASPNET MVC RC1 迁移到 RC2:

• https://www.youtube.com/watch?v=FPf3D9CqRDk

• https://www.wildermuth.com/2016/05/17/Converting-an-ASP-NET-Core-RC1-Project-to-RC2

到目前为止，我设法让我的应用程序编译，但它在运行时中断，显示以下与 Entity Framework 相关的错误:

An exception of type 'System.InvalidOperationException' occurred in Microsoft.EntityFrameworkCore.dll but was not handled in user code

Additional information: Cannot remove key {Id} from entity type Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityUser because it is referenced by a foreign key in entity type Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityUserClaim<string>. All foreign keys must be removed or redefined before the referenced key can be removed.

下面是我在上下文类中使用的代码:

public class AppContext : IdentityDbContext
{
    public DbSet<Entity1> Entities1 { get; set; }
    public DbSet<Entity2> Entities2 { get; set; }
    public DbSet<Entity3> Entities3 { get; set; }
    public DbSet<ApplicationUser> ApplicantionUsers { get; set; }

    public AppContext(DbContextOptions<AppContext> options) : base(options)
    {
        ChangeTracker.AutoDetectChangesEnabled = false;
        Database.EnsureCreated();
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("the connection string...");
        base.OnConfiguring(optionsBuilder);
    }
}

代码在 AppContext 构造函数中中断(第一行)。我尝试删除该行，但它在下一行中断了。如果我删除 DbSet，代码会通过，但不会创建表。

我尝试向 ApplicationUser 类添加一个公共(public)字符串 Id 属性(尽管它应该从 IdentityUser 继承它)但是得到了同样的错误。下面是 ApplicationUser 类的代码:

using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;

namespace AppNamespace
{
    public class ApplicationUser : IdentityUser
    {
        public enum Gender { Male, Female }

        public enum UserStatus { Inactive, Active }

        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Passport { get; set; }

        public Gender Gender { get; set; }
        public DateTime Birthday { get; set; }
        public UserStatus Status { get; set; }
        public int ReferenceNumber { get; private set; }
        public int Referral { get; set; }
        public bool AcceptedTermsAndConditions { get; set; }

        public string Telephone { get; set; }
        public string Mobile { get; set; }

        public string AddressLine { get; set; }
        public string ZipCode { get; set; }
        public string City { get; set; }
        public string State { get; set; }
        public Country Country { get; set; }

        public ApplicationUser()
        {
        }
    }
}

谢谢， 贡萨洛

Answer 1

好的，问题是上下文在从 IdentityDbContext 派生时没有提供 ApplicationUser。 这解决了问题:

public class AppContext : IdentityDbContext<ApplicationUser>
{ 
    ...
}