ASP.Net Core 3 排序外键下拉选择列表

Question

我有两个不同的 ASP.net Core 3 应用程序正在运行，它们的表使用外键链接到其他表。在 CRUD 页面中，下拉列表正常工作并显示数据，但数据按主键的顺序排序，主键通常是整数索引键。我希望弄清楚如何根据显示的值按排序顺序显示这些下拉列表。我还没有找到任何可以完成这项工作的命令。任何帮助，将不胜感激。项目的外键是 Street 和 TownProperty。我会附上代码文件；

Projects Controller.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using TOGProjects.Models;

namespace TOGProjects.Controllers
{
    public class ProjectsController : Controller
    {
        private readonly TOGProjectsContext _context;

        public ProjectsController(TOGProjectsContext context)
        {
            _context = context;
        }

        // GET: Projects
        public async Task<IActionResult> Index()
        {
            var tOGProjectsContext = _context.Projects.Include(p => p.Street).Include(p => p.TownProperty);
            return View(await tOGProjectsContext.ToListAsync());
        }

        // add Search ablity on the Index Page
        [HttpGet]
        public async Task<IActionResult> Index(String Projectsearch)
        {
            ViewData["GetProjectDetails"] = Projectsearch;

            var projectquery = _context.Projects
                                    .Include(s => s.Street)
                                    .Include(s => s.TownProperty)
                                    .AsQueryable();



            if (!String.IsNullOrEmpty(Projectsearch))
            {
                projectquery = projectquery.Where(x => x.ProjectDescription.Contains(Projectsearch) || x.Pwnum.Contains(Projectsearch));
            }
            return View(await projectquery.AsNoTracking().ToListAsync());
        }

        // GET: Projects/Details/5
        public async Task<IActionResult> Details(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var projects = await _context.Projects
                .Include(p => p.Street)
                .Include(p => p.TownProperty)
                .FirstOrDefaultAsync(m => m.ProjectId == id);
            if (projects == null)
            {
                return NotFound();
            }

            return View(projects);
        }

        // GET: Projects/Create
        public IActionResult Create()
        {
            ViewData["StreetId"] = new SelectList(_context.StreetNames, "StreetId", "Streets");
            ViewData["TownPropertyId"] = new SelectList(_context.TownProperties, "TownPropertyId", "TownPropertyName");
            return View();
        }

        // POST: Projects/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Create([Bind("ProjectId,ProjectDescription,DateStarted,Pwnum,StreetId,StateProjectNumber,TownPropertyId,CapitalAccount")] Projects projects)
        {
            if (ModelState.IsValid)
            {
                _context.Add(projects);
                await _context.SaveChangesAsync();
                return RedirectToAction(nameof(Index));
            }
            ViewData["StreetId"] = new SelectList(_context.StreetNames, "StreetId", "Streets", projects.StreetId);
            ViewData["TownPropertyId"] = new SelectList(_context.TownProperties, "TownPropertyId", "TownPropertyName", projects.TownPropertyId);
            return View(projects);
        }

        // GET: Projects/Edit/5
        public async Task<IActionResult> Edit(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var projects = await _context.Projects.FindAsync(id);
            if (projects == null)
            {
                return NotFound();
            }
            ViewData["StreetId"] = new SelectList(_context.StreetNames, "StreetId", "Streets", projects.StreetId);
            ViewData["TownPropertyId"] = new SelectList(_context.TownProperties, "TownPropertyId", "TownPropertyName", projects.TownPropertyId);
            return View(projects);
        }

        // POST: Projects/Edit/5
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Edit(int id, [Bind("ProjectId,ProjectDescription,DateStarted,Pwnum,StreetId,StateProjectNumber,TownPropertyId,CapitalAccount")] Projects projects)
        {
            if (id != projects.ProjectId)
            {
                return NotFound();
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(projects);
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!ProjectsExists(projects.ProjectId))
                    {
                        return NotFound();
                    }
                    else
                    {
                        throw;
                    }
                }
                return RedirectToAction(nameof(Index));
            }
            ViewData["StreetId"] = new SelectList(_context.StreetNames, "StreetId", "Streets", projects.StreetId);
            ViewData["TownPropertyId"] = new SelectList(_context.TownProperties, "TownPropertyId", "TownPropertyName", projects.TownPropertyId);
            return View(projects);
        }

        // GET: Projects/Delete/5
        public async Task<IActionResult> Delete(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var projects = await _context.Projects
                .Include(p => p.Street)
                .Include(p => p.TownProperty)
                .FirstOrDefaultAsync(m => m.ProjectId == id);
            if (projects == null)
            {
                return NotFound();
            }

            return View(projects);
        }

        // POST: Projects/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> DeleteConfirmed(int id)
        {
            var projects = await _context.Projects.FindAsync(id);
            _context.Projects.Remove(projects);
            await _context.SaveChangesAsync();
            return RedirectToAction(nameof(Index));
        }

        private bool ProjectsExists(int id)
        {
            return _context.Projects.Any(e => e.ProjectId == id);
        }
    }
}

Projects.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;

namespace TOGProjects.Models
{
    public partial class Projects
    {
        public int ProjectId { get; set; }
        [DisplayName("Project Description")]
        [Required, StringLength(50)]
        [RegularExpression(@"(([A-za-z0-9\s\-]+))$")]
        public string ProjectDescription { get; set; }
        [DisplayName("Date Started")]
        [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
        public DateTime? DateStarted { get; set; }
        [DisplayName("Engineering Project Number")]
        public string Pwnum { get; set; }
        public int? StreetId { get; set; }
        [DisplayName("State Project Number")]
        [StringLength(15)]
        public string StateProjectNumber { get; set; }
        public int? TownPropertyId { get; set; }
        [DisplayName("Capital Account")]
        [StringLength(30)]
        public string CapitalAccount { get; set; }

        public virtual StreetNames Street { get; set; }
        [DisplayName("Town Property Name")]
        [StringLength(50)]
        public virtual TownProperties TownProperty { get; set; }
    }
}

项目索引.cshtml

@model TOGProjects.Models.Projects

@{
    ViewData["Title"] = "Edit";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h1>Edit</h1>

<h4>Projects</h4>
<hr />
<div class="row">
    <div class="col-md-4">
        <form asp-action="Edit">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <input type="hidden" asp-for="ProjectId" />
            <div class="form-group">
                <label asp-for="ProjectDescription" class="control-label"></label>
                <input asp-for="ProjectDescription" class="form-control" />
                <span asp-validation-for="ProjectDescription" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="DateStarted" class="control-label"></label>
                <input asp-for="DateStarted" class="form-control" />
                <span asp-validation-for="DateStarted" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Pwnum" class="control-label"></label>
                <input asp-for="Pwnum" class="form-control" />
                <span asp-validation-for="Pwnum" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="StreetId" class="control-label"></label>
                <select asp-for="StreetId" class="form-control" asp-items="ViewBag.StreetId"></select>
                <span asp-validation-for="StreetId" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="StateProjectNumber" class="control-label"></label>
                <input asp-for="StateProjectNumber" class="form-control" />
                <span asp-validation-for="StateProjectNumber" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="TownPropertyId" class="control-label"></label>
                <select asp-for="TownPropertyId" class="form-control" asp-items="ViewBag.TownPropertyId"></select>
                <span asp-validation-for="TownPropertyId" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="CapitalAccount" class="control-label"></label>
                <input asp-for="CapitalAccount" class="form-control" />
                <span asp-validation-for="CapitalAccount" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Save" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

<div>
    <a asp-action="Index">Back to List</a>
</div>

@section Scripts {
    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

谢谢

Answer 1

您需要将OrderBy 添加到您的数据中，如下所示。

ViewData["StreetId"] = new SelectList(_context.StreetNames.OrderBy(s => s.Streets), "StreetId", "Streets");
ViewData["TownPropertyId"] = new SelectList(_context.TownProperties.OrderBy(t => t.TownPropertyName), "TownPropertyId", "TownPropertyName");