c# - 属性 'x' 不是实体类型 'y' 的导航属性

Question

我将 EF Core 与 ASP Core 2.0 结合使用。使用最新的身份框架。我在所有页面上得到这个异常。

InvalidOperationException: The property 'User' is not a navigation property of entity type 'Gallery'. The 'Include(string)' method can only be used with a '.' separated list of navigation property names.

ApplicationUser 看起来像:

public class ApplicationUser : IdentityUser<Guid>
{
    public ICollection<Gallery> Galleries { get; set; }
}

实体库看起来像:

public class Gallery
{
    public int Id { get; set; }
    public Guid UserId { get; set; }
    public string Title { get; set; }
    public int? ArticleId { get; set; }
    public string Photos { get; set; }
    public DateTime CreatedAt { get; set; }
    public DateTime UpdatedAt { get; set; }

    public Article Article { get; set; }
    public ApplicationUser User { get; set; }

    [NotMapped]
    public List<string> PhotosList
    {
        get { return Photos?.Split('|').ToList(); }
        set { Photos = string.Join("|", value); }
    }
}

View Controller 看起来像:

public async Task<IActionResult> All()
    {
        var databaseContext = db.Galleries.Include(x => x.Article).Include(x => x.User);

        return View(await databaseContext.ToListAsync());
    }

我不知道为什么它不会在 Article 上崩溃..

数据库是最新的。

Answer 1

添加一个ForeignKey属性

using System.ComponentModel.DataAnnotations.Schema;

...

[ForeignKey("Article")]
public int? ArticleId { get; set; }

[ForeignKey("User")]
public Guid UserId { get; set; }

你也可以把属性放在导航属性上

[ForeignKey("UserId")]
public ApplicationUser User { get; set; }

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此外，请确保您的 dbContext 继承自 IdentityDbContext<ApplicationUser, ...>