Question

我已经搜索过并尝试过针对我的问题的十几种解决方案，但是无法解决这个问题。

我在这里压缩了类定义，但这里是主要部分。

public class ApplicationUser : IdentityUser
{
    public ApplicationUser()
    {
        this.Device = new HashSet<Device>();
    }
    public virtual ICollection<Device> Devices { get; set; }
}

public class Device
{
    public Device()
    {
    }
    public int      Id { get; set; }
    public string   DeviceId { get; set; }
    public virtual ApplicationUser  User { get; set; }
}

UserController.cs：

public async Task<ActionResult> SaveDevice(string id, string selection)
{
    var selectedDevice = db.Devices.Where(u => u.DeviceId.Equals(selection));
    var user = await UserManager.FindByIdAsync(id);
    user.Devices.Add(selectedDevice.First());

==> here everything looks ok, device data can be seen from the user data
==> in comments different things that I have tried so far, without getting anything to work
    //db.Entry(user).Property(p => p.Devices).IsModified = true;
    //db.Entry(user).Reference(p => p.Devices).IsLoaded = true;
    //db.Entry(user).Collection(p => p.Devices).IsLoaded = true;
    //db.Entry(user).State = EntityState.Modified;
    db.Users.Attach(user);
    db.SaveChanges();

    return RedirectToAction("Index");
}

==＆GT;现在，当我返回用户详细信息视图时，设备数据为空，因此没有任何内容存储到db

如何使用MVC 5将ICollection数据保存到数据库

0 个答案: