Question

我正在使用mvc 4.5并尝试创建Events页面，每个Event都会有Event Attendees列表;我添加了类MyEvent和类Attendee

public class MyEvent
{
    public MyEvent()
    { 
       Attendees = new List<Attendee>();              
    }

    [Required]            
    public int Id { get; set; }

    [Required]
    [Display(Name = "Date")]
    public DateTime EventDate { get; set; }

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

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

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

    public List<Attendee> Attendees { get; set; }

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

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

public class Attendee
{
    public int Id { get; set; }
    public string Name { get; set; }

    public Attendee(String name)
    {
        this.Name = name;
    }        
}

EF创建了表MyEvents，Attendees和Attendees的Fk MyEvent_Id指向了MyEvent表的Id;问题我无法在代码中访问MyEvent_Id，而我可以访问其余列（Id和Name），另一个问题是MyEvent Entity的Attendees列表似乎一遍又一遍地更新并且只包含最后一个attndee;我希望能够让所有与活动相关的与会者都能够显示所有活动参与者

Answer 1

听起来您正在尝试从参加者访问MyEvent对象，但是您缺少导航属性来访问您的事件对象。您的参加者类应该看起来像这样

public class Attendee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int MyEventID { get; set; }

    public virtual MyEvent MyEvent { get; set; }

    public Attendee(String name)
    {
        this.Name = name;
    }        
}

你的第二个问题对我来说并不是很清楚。实际框架通常仅在您实际访问实体时从数据库中读取参加者。您应该能够毫无问题地遍历参加者列表。

无法访问实体frameork创建的表中的外键

1 个答案: