Question

我正在使用Entity Framework Core构建一个简单的Web应用程序。对于这个应用程序，我创建了一个名为Company的模型，其中包括基本业务信息+联系人列表（销售代表）。

这是我的模特：

public class Company
{
    [Key]
    public int ID { get; set; }
    public string Name { get; set; }
    public string Promo { get; set; } 
    public virtual List<Contact> Contacts { get; set; }       
}

public class Contact
{
    [Key]
    public int ContactID { get; set; }
    [ForeignKey("Company")]
    public int CompanyID { get; set; }
    public virtual Company Company { get; set; }
    public string ContactName { get; set; }
    public string ContactNumber { get; set; }
}

这是控制器的index（）方法：

// GET: Companies
    public async Task<IActionResult> Index()
    {
        List<Company> viewModelData = await _context.Companies
            .Include(c => c.Contacts)
            .ToListAsync();
        return View(viewModelData);
    }

编辑方法：

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

            var company = await _context.Companies
                .Include(v => v.Contacts)
                .FirstOrDefaultAsync(m => m.ID == id);
            if (company == null)
            {
                return NotFound();
            }
            return View(company);
        }

        // POST: Companies/Edit/5

        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Edit(int? id, [Bind("ID,Name,Promo,Contacts")] Company company)
        {
            if (id == null)
            {
                return NotFound();
            }

            var companyToUpdate = await _context.Companies
                .Include(v => v.Contacts)
                .FirstOrDefaultAsync(m => m.ID == id);
            if (await TryUpdateModelAsync<Company>(
                companyToUpdate,
                "",
                i => i.Name, i => i.Promo, i => i.Contacts
                )) { 
                try
                {
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateException /* ex */)
                {
                    //Log the error (uncomment ex variable name and write a log.)
                    ModelState.AddModelError("", "Unable to save changes. " +
                        "Try again, and if the problem persists, " +
                        "see your system administrator.");
                }
            return RedirectToAction("Index");
        }
         return View(companyToUpdate);
    }

这是不正确的，因为代码只允许我编辑公司信息。如何修改代码以便我可以编辑公司和它在同一编辑视图中的联系人？

Answer 1

如果您纯粹希望更新值，那么您可以像这样明确地更新它们。还建议使用View Model，但这可以归结为良好与不良练习。这省略了异常处理，仅作为如何映射这些值的示例，您必须修改控制器的其余部分才能直接使用CompanyEditViewModel

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(int? id, [Bind("ID,Name,Promo,Contacts")] CompanyEditViewModel company)
{
    if (!ModelState.IsValid)
        return RedirectToAction("Index");

    var companyToUpdate = await _context.Companies
        .Include(v => v.Contacts)
        .FirstOrDefaultAsync(m => m.ID == id);

    // Assign the new values
    companyToUpdate.Name = company.Name;
    companyToUpdate.Promo = company.Promo;
    companyToUpdate.Contacts = company.Contacts?.ToList();

    // Update and save
    _context.Companies.Update(companyToUpdate);
    await _context.SaveChangesAsync();

    return View(companyToUpdate);
}

public class Company
{
    public int ID { get; set; }
    public string Name { get; set; }
    public string Promo { get; set; } // Yes or No field
    public List<Contact> Contacts { get; set; }

    public class Contact
    {
        [Key]
        public int ContactID { get; set; }

        public int CompanyID { get; set; }
        public string ContactName { get; set; }
        public string ContactNumber { get; set; }
    }
}

// The View Model contains the Company details which were modified
// The first Edit method will have to be updated to bind this View Model to the view
public class CompanyEditViewModel
{
    public int ID { get; set; }
    public string Name { get; set; }
    public string Promo { get; set; }
    public IList<Company.Contact> Contacts { get; set; }
}

允许用户编辑MVC中的列表项？

1 个答案: