如何在 ASP.NET Core 3.1 中显示连接模型的属性值

Question

我在查看公司列表中显示用户名（创建公司的人）时遇到问题。

这是模型“User.cs”的一部分：

using System;
using System.Collections.Generic;

public partial class User
{
    public User()
    {
        // init here
    }
    // Connections with other Models are here as ICollection

    public int Id { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
    public DateTime Created { get; set; }
}

这里是模型“Company.cs”：

using System;
using System.Collections.Generic;

public partial class Company
{
    public Company()
    {
        Accounts = new HashSet<Accounts>();
        CompanyHistory= new HashSet<CompanyHistory>();
        Earnings= new HashSet<Earnings>();
        Expences= new HashSet<Expences>();
    }
    // other properties those aren't important
    public int? UserID { get; set; } // here is User ID

    // Other connections those aren't important
    public virtual User UserNavigation { get; set; } // Here is connection with Users
}

这是控制器“CompamyController.cs”的一部分：

public class CompanyController : Controller
{
    private readonly MyDBContext _dbContext;
    public PoslodavacController(MyDBContext dbContext)
    {
        _dbContext = dbContext;
    }

    public IActionResult ViewCompanies()
    {
        return View(_dbContext.Company);
    }
    
    // other code irrelevant for this problem/solution
}

这是查看“ViewCompanies.cshtml”：

@model IEnumerable<MyDatabase.Models.Company>
@using MyDatabase.Models;
@{
    ViewData["Title"] = "ViewCompanies";
    Layout = "_Layout";
}

<h1>ViewCompanies</h1>

<p>
    <a asp-action="Create">Create New</a>
</p>
<table class="table">
    <thead>
        <tr>
            <!-- other html -->
            <th>
                <p>User Name</p>
            </th>
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model)
        {
            <tr>
                <!-- Other html data -->
                <td>
                <!-- ATENTION HERE: @item.KorisnikNavigation is always null so the Name is not retrieved-->
                    <a asp-route-id="@item.User" asp-controller="User" asp-action="Details">@item.UserNavigation?.Name</a>
                </td>
            </tr>
        }
    </tbody>
</table>

我不知道为什么@item.KorisnikNavigation 为空。 我错过了 Company 构造函数中的一些代码吗？如果有，需要的代码是什么？

谢谢！

Answer 1

修正动作

public IActionResult ViewCompanies()
    {
var model=_dbContext.Set<Company>().Include(i=> i.UserNavigation ).ToArray();
        return View(model);
    }