asp.net-core - 在 Asp.Net Core 中使用 SelectList 创建视图时显示值而不是 id

Question

我正在开发 Asp.Net Core 应用程序。我有 4 个相关的表。

城市、街道、房屋和警报装置

该应用程序用于管理警报安装。

房子属于街道和城市，它们是相关的。House 具有 DoorNr 属性...

当我尝试创建新的警报安装时。它向我展示了我通过 ID 可用的房屋，但我需要它来显示完整地址。问题是房屋类只有 StreetId（来自 Street Class）和 DoorNr。我怎样才能让它显示完整的地址？

            public partial class AlarmInstall
            {
                public int AlarmInstallId { get; set; }
                public int HouseId { get; set; }
                public string Model { get; set; }

                public virtual House House { get; set; }
            }

            public partial class House
            {
                public House()
                {
                    AlarmInstall = new HashSet<AlarmInstall>();
                }

                public int HouseId { get; set; }
                public int StreetId { get; set; }
                public string DoorNr { get; set; }
                public int CityId { get; set; }

                public virtual City City { get; set; }
                public virtual Street Street { get; set; }
                public virtual ICollection<AlarmInstall> AlarmInstall { get; set; }
            }

            public partial class Street
            {
                public Street()
                {
                    House = new HashSet<House>();
                }

                public int StreetId { get; set; }
                public string StreetName { get; set; }

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

            public partial class City
            {
                public City()
                {
                    House = new HashSet<House>();
                }

                public int CityId { get; set; }
                public string CityName { get; set; }

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

我的 AlarmsInstallController 有以下代码：

            // GET: AlarmInstalls/Create
            public IActionResult Create()
            {
                ViewData["HouseId"] = new SelectList(_context.House, "HouseId", "HouseId");
                return View();
            }

            // POST: AlarmInstalls/Create

            [HttpPost]
            [ValidateAntiForgeryToken]
            public async Task<IActionResult> Create([Bind("AlarmInstallId,HouseId,Model")] AlarmInstall alarmInstall)
            {
                if (ModelState.IsValid)
                {
                    _context.Add(alarmInstall);
                    await _context.SaveChangesAsync();
                    return RedirectToAction(nameof(Index));
                }
                ViewData["HouseId"] = new SelectList(_context.House, "HouseId", "DoorNr", alarmInstall.HouseId);
                return View(alarmInstall);
            }

我的视图有以下代码：

            <form asp-action="Create">
                <div asp-validation-summary="ModelOnly" class="text-danger"></div>
                <div class="form-group">
                    <label asp-for="HouseId" class="control-label"></label>
                    <select asp-for="HouseId" class ="form-control" asp-items="ViewBag.HouseId"></select>
                </div>

这是我的 HouseId 选择列表...

            ViewData["HouseId"] = new SelectList(_context.House, "HouseId", "HouseId");

我需要显示完整的地址，由 streetName（来自 StreetClass）和 DoorNr 组成，而不是 HouseId，我应该在我的代码中更改什么？

提前感谢您的帮助！！！

标签： asp.net-core

Answer 1

在google的帮助下自己解决...

    public IActionResult Create()
    {
        //   ViewData["HouseId"] = new SelectList(_context.House, "HouseId", "HouseId");

        var fullAddress = _context.House
                            .Select(h => new { HouseId = h.HouseId, FullAddress = h.Street.StreetName
                           + ", " + h.DoorNr })
                            .ToList();

        ViewBag.HouseId = new SelectList(fullAddress, "HouseId", "FullAddress");