从视图

Question

当调用一个显示我已扩展的ASP.NET的ApplicationUser类的属性的视图时，当代码尝试渲染我潜入ApplicationUser类的行时，我收到以下错误：

@model BaseballStatTracker.Models.ApplicationUser

@foreach (var stats in Model.GameStatistics)
{
    <tr>
        <td>
            @Html.DisplayFor(modelItem => stat.Game.GameTime)
        </td>
    </tr>
}

...的原因：

从“Game”属性中访问的任何属性都会导致错误，并且Razor在编辑视图时没有指出存在问题。只需访问GameStatistics上的常规属性即可正常运行。

我有两种情况;标准的ApplicationDbContext和我的GamesContext包含Game和GameStatistics实体。我已根据以下内容覆盖了GamesContext上的OnModelCreating方法：

protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Game>().HasKey(i => i.GameId);
            modelBuilder.Entity<Game>().HasOptional(i => i.HomeTeam).WithMany(i => i.HomeGames).HasForeignKey(i => i.HomeTeamId);
            modelBuilder.Entity<Game>().HasOptional(i => i.AwayTeam).WithMany(i => i.AwayGames).HasForeignKey(i => i.AwayTeamId);
            modelBuilder.Entity<Game>().HasOptional(i => i.Diamond).WithMany(i => i.Games).HasForeignKey(i => i.DiamondId);

            modelBuilder.Entity<GameStatistics>().HasKey(i => i.GameStatisticsId);
            modelBuilder.Entity<GameStatistics>().HasRequired(i => i.Game).WithMany(i => i.GameStatistics).HasForeignKey(i => i.GameId);
            modelBuilder.Entity<GameStatistics>().HasRequired(i => i.Player).WithMany(i => i.GameStatistics).HasForeignKey(i => i.PlayerId);
...
}

ApplicationUser，Game和GameStatistics类如下所示：

ApplicationUser：

public class ApplicationUser : IdentityUser
    {
        public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
        {
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
            // Add custom user claims here
            return userIdentity;
        }

        [Required]
        [Display(Name = "First Name")]
        [StringLength(155, ErrorMessage = "First Name can only be max 155 characters in length.")]
        public string FirstName { get; set; }

        [Display(Name = "Last Name")]
        [StringLength(155, ErrorMessage = "Last Name can only be max 155 characters in length.")]
        public string LastName { get; set; }

        [Display(Name = "Full Name")]
        public string FullName
        {
            get
            {
                return FirstName + " " + LastName;
            }
        }

        [Display(Name = "Player Number")]
        public int PlayerNumber { get; set; }

        [Display(Name = "Team")]
        public virtual Guid TeamId { get; set; }
        public virtual Team Team { get; set; }

        public virtual ICollection<GameStatistics> GameStatistics { get; set; }
    }

游戏：

public class Game
    {
        [Key]
        public Guid GameId { get; set; }

        public string GameName { get
            {
                return AwayTeam.Name + " @ " + HomeTeam.Name + ", " + GameDate.Value.Date.ToLongDateString();
            } }

        [DataType(DataType.Date)]
        [Display(Name = "Game Date")]
        public DateTime? GameDate { get; set; }

        [DataType(DataType.Time)]
        [Display(Name = "Game Time")]
        public DateTime? GameTime { get; set; }

        [Display(Name = "Game Location")]
        public virtual Guid? DiamondId { get; set; }
        public virtual Diamond Diamond { get; set; }

        [Display(Name = "Home Team")]
        public virtual Guid? HomeTeamId { get; set; }
        public virtual Team HomeTeam { get; set; }

        [Display(Name = "Away Team")]
        public virtual Guid? AwayTeamId { get; set; }
        public virtual Team AwayTeam { get; set; }

        public virtual ICollection<GameStatistics> GameStatistics { get; set; }
    }

GameStatistics：

public class GameStatistics
    {
        [Key]
        public Guid GameStatisticsId { get; set; }

        public Guid GameId { get; set; }
        public virtual Game Game { get; set; }

        public string PlayerId { get; set; }
        public virtual ApplicationUser Player { get; set; }

        public int AtBats { get; set; }

        public int Hits { get; set; }

        public int Walks { get; set; }
    }

我已经尝试重做OnModelCreate方法，但我无法看到我对Game＆lt; -GameStatistics关系做错了什么。任何帮助将非常感激。提前谢谢 -

Answer 1

在HomeTeam和AwayTeam属性上为我的游戏模型添加了几个“反向属性”注释后，此问题得以解决。我也不再使用OnModelCreating覆盖并切换到完全使用注释。代码更改的相关部分是：

    [Display(Name = "Home Team")]
    public virtual Guid? HomeTeamId { get; set; }

    [ForeignKey("HomeTeamId")]
    [InverseProperty("HomeGames")] // Added this - 
    public virtual Team HomeTeam { get; set; }

    [Display(Name = "Away Team")]
    public virtual Guid? AwayTeamId { get; set; }

    [ForeignKey("AwayTeamId")]
    [InverseProperty("AwayGames")] // Added this - 
    public virtual Team AwayTeam { get; set; }

我不确定为什么我无法在数据上下文中设置相同的结果 - 我确信这只是我的误解，但我很想知道原因。如果EF通过配置不知道逆特性是什么？

我曾尝试更改配置设置但没有效果 - 但是我首先看不出它有什么问题。尽管如此，它现在正在使用数据注释。