c# - 如何实现包含复选框列表 ASP.Net Core MVC 的编辑操作？

Question

我有两个表“项目”和“办公室”，我想实现产生“项目管理”表的“多对多”关系。

我想在创建项目时定义负责办公室，我实现了创建操作但我在[HttpPost]编辑操作中遇到了问题，我通过删除“ProjectManagement”表中与当前相关的所有先前记录来解决它编辑过的项目然后重新保存新的编辑，但似乎不太好。

项目.cs

public class Project 
    {
        public int Id { get; set; } 
        public string ProjectCode { get; set; } 
        public string Donor { get; set; } 
        public DateTime StartDate { get; set; } 
        public DateTime EndtDate { get; set; }
        
    }

Office.cs

public class Office 
    {
        public int Id { get; set; } 
        public int RegionId { get; set; }
        public string OfficeName { get; set; }
        public string OfficeAddress { get; set; }
        public string Latitude_y { get; set; }
        public string Longitude_x { get; set; }
        public virtual Region Region { get; set; }
        public bool Selected { get; set; }

    }

项目管理.cs

public class ProjectManagement 
    {
        public int Id { get; set; }
        public int ProjectId { get; set; }
        public int OfficeId { get; set; }
        public virtual Project Project { get; set; }
        public virtual Office Office { get; set; }
    }

项目视图模型.cs

public class ProjectViewModel
    {
        public int Id { get; set; }
        public string ProjectCode { get; set; }
        public string Donor { get; set; }
        public DateTime StartDate { get; set; } 
        public DateTime EndtDate { get; set; }
        public string Notes { get; set; }
        public IList<SelectListItem> Offices { get; set; }
        
    }

// GET：项目/创建

public IActionResult Create()
{
    var offices = _office.Entity.GetAll();
    
    var item = offices.Select(x => new SelectListItem()
    {
        Text = x.OfficeName,
        Value = x.Id.ToString()
    }).ToList();

    var projectVM = new ProjectViewModel()
    {
        Offices = item
        
    };
    return View(projectVM);
}

// POST：项目/创建

[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Create(ProjectViewModel model)
{
    if (ModelState.IsValid)
    {
        Project project = new Project
        {
            ProjectCode = model.ProjectCode,
            Donor = model.Donor,
            StartDate = model.StartDate,
            EndtDate = model.EndtDate

        };
        _project.Entity.Insert(project);
        _project.Save();

       var officeIds = model.Offices.Where(x => x.Selected).Select(y => y.Value);
        foreach (var id in officeIds)
        {
            ProjectManagement pm = new ProjectManagement
            {
                OfficeId = int.Parse(id),
                ProjectId = project.Id
            };
            _projectManagement.Entity.Insert(pm);
            _projectManagement.Save();
        } 

        return RedirectToAction(nameof(Index));
    }

    return View(model);
}

// 获取：项目/编辑/5

        public IActionResult Edit(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var project = _project.Entity.GetById(id);
            if (project == null)
            {
                return NotFound();
            }

  var selectedoffices = _projectManagement.Entity.GetAll().Where(a => a.ProjectId == id);
            var offices = _office.Entity.GetAll();
                            
            foreach (var i in selectedoffices)
            {
                i.Office.Selected = true;
            }

            var item = offices.Select(x => new SelectListItem()
            {
                Text = x.OfficeName,
                Value = x.Id.ToString(),
                Selected = x.Selected
            }).ToList();

            

            ProjectViewModel projectViewModel = new ProjectViewModel
            {
                Id = project.Id,
                ProjectCode = project.ProjectCode,
                Donor = project.Donor,
                StartDate = project.StartDate,
                EndtDate = project.EndtDate,
                Offices = item
            };
            return View(projectViewModel);
        }

// 发布：项目/编辑/5

[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Edit(int id, ProjectViewModel model)
{
    if (id != model.Id)
    {
        return NotFound();
    }

    if (ModelState.IsValid)
    {
        try
        {

            Project project = new Project
            {
                Id = model.Id,
                ProjectCode = model.ProjectCode,
                Donor = model.Donor,
                StartDate = model.StartDate,
                EndtDate = model.EndtDate
            };

            _project.Entity.Update(project);
            _project.Save();
        }

        catch (DbUpdateConcurrencyException)
        {
            if (!ProjectExists(model.Id))
            {
                return NotFound();
            }
            else
            {
                throw;
            }
        }
        var officeIds = model.Offices.Where(x => x.Selected).Select(y => y.Value);
        var existingoffices = _projectManagement.Entity.GetAll().Where(x => x.ProjectId == id).ToList();
        foreach (var item in existingoffices)
        {
            _projectManagement.Entity.Delete(item.Id);
            _projectManagement.Save();
        }

        foreach (var i in officeIds)
        {

            ProjectManagement pm = new ProjectManagement
            {
                OfficeId = int.Parse(i),
                ProjectId = id
            };
            _projectManagement.Entity.Insert(pm);
            _projectManagement.Save();

        }

        return RedirectToAction(nameof(Index));

    }
    return View(model);
}

编辑视图：

<div class="form-group">
                @for (int i = 0; i < Model.Offices.Count; i++)
                {

                    <input type="hidden" asp-for="@Model.Offices[i].Value" />
                    <input asp-for="Offices[i].Selected" />@Model.Offices[i].Text
                }
            </div>

标签： c#asp.net-core-mvcedit