Question

我有一个名为RegisterViewModel的视图模型 -

public class RegisterViewModel
    {
        public string UserName { get; set; }
        public string Email { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
}

和两个名为User和UserDetails的模型

public class User
    {
        [Key]
        public string UserName { get; set; }
        public string Email { get; set; }

        public virtual ICollection<Role> Roles { get; set; }
        public virtual UserDetails UserDetails { get; set; }
}


 public class UserDetails
    {

        [Key]
        public string UserName { get; set; }
        public string Firstname { get; set; }
        public string Lastname { get; set; }

        [Required]
        public virtual User User { get; set; }
}

在我的用户控制器中，我的详细信息方法有以下内容 -

public ViewResult Details(string id)
        {
            User user = context.Users
                .Include (i => i.UserDetails)
                .Where(i => i.UserName == id)
                .Single();

            user.UserDetails = new UserDetails();

            RegisterViewModel viewModel = new RegisterViewModel{
                UserName = user.UserName,
                FirstName = user.UserDetails.FirstName,
                LastName = user.UserDetails.LastName,
                Salary = user.UserDetails.Salary,
                Email = user.Email,
                Roles = user.Roles
            };
            return View(viewModel);
        }

在我的详细信息视图中 -

@model TRS.ViewModels.RegisterViewModel
<table>
<tr>
    <td>User Name</td>
    <td>@Model.UserName</td>
</tr>
<tr>
    <td>Email</td>
    <td>@Model.Email</td>
</tr>
<tr>
    <td>First Name</td>
    <td>@Model.FirstName</td>
</tr>
<tr>
    <td>Last Name</td>
    <td>@Model.LastName</td>
</tr>
<tr>
    <td>Roles</td>
    <td>@foreach (Role role in Model.Roles) {
        @role.RoleName<br />
    }</td>
</tr>

但我只是从User模型获取日期，没有UserDetails的日期。所以我可以看到用户名，电子邮件和rolles，但不能看到名字或姓氏。

你能看到我在哪里出错吗？

由于

Answer 1

删除该行

user.UserDetails = new UserDetails();

这样做，您可以创建一个新的空UserDetails实例。

来自您的上下文的user.UserDetails将被该空实例替换。

修改

可能最好避免NRE

user.UserDetails = user.UserDetails ?? new UserDetails();

Answer 2

不要使用user.UserDetails = new UserDetails（）它将详细信息从db更改为新的详细信息。您可以在linq请求中获取您的viewmodel：

public ViewResult Details(string id)
    {
        var viewmodel = context.Users
            .Where(i => i.UserName == id)
            .Select(user=>new RegisterViewModel
                {
                    UserName = user.UserName,
                    FirstName = user.UserDetails.FirstName,
                    LastName = user.UserDetails.LastName,
                    Salary = user.UserDetails.Salary,
                    Email = user.Email,
                    Roles = user.Roles
                })
            .Single();


        return View(viewModel);
    }

ViewModel不显示相关数据

2 个答案: