Question

有没有办法以某种方式组合来自两个模型的数据，然后在编辑操作的上下文中将它们两个映射到同一个viewModel？

我从未在使用Entity Framework 6.1.3的ASP.NET MVC中的编辑操作中一次更新多个表。这是布局：

我有一个名为“地址”的数据库表，其中包含StreetNumber，StreetName，City，State，ZipCode的字段。它与另一个名为Bars的表具有一对一关系。同样，一个栏只能有一个地址，一个地址只能有一个栏。

因为我将这些数据存储在两个单独的表中，所以我很难尝试成功实现一个Edit动作，该动作从一个表单（BarForm）获取数据，并且应该同时更新Bar和地址数据库表。看我的代码：

BarController

public ActionResult Edit(int id)
        {

            var bar = _context.Bars.SingleOrDefault(m => m.Id == id);
            var address = _context.Addresses.SingleOrDefault(a => a.BarId == id);
            //Make sure that the id actually exists:
            if (bar == null)
            {
                return HttpNotFound();
            }
            var viewModel = Mapper.Map<Bar, BarFormViewModel>(bar, new BarFormViewModel());
            if (address == null)
            {
                address = new Address();
            }
            Mapper.Map<Address, BarFormViewModel>(address, viewModel);

            viewModel.IsNew = false;

            return View("BarForm", viewModel);
        }
        [ValidateAntiForgeryToken]
        public ActionResult Save(BarFormViewModel bar)
        {

            if (!ModelState.IsValid)
            {
                var viewModel = Mapper.Map<BarFormViewModel, BarFormViewModel>(bar, new BarFormViewModel());
                viewModel.IsNew = false;
                return View("BarForm", viewModel);

            }
            if (bar.Id == 0)
            {

                var newbar = Mapper.Map<BarFormViewModel, Bar>(bar);
                newbar.LastUpdated = DateTime.UtcNow;
                _context.Bars.Add(newbar);
                var addressToAdd = Mapper.Map<BarFormViewModel, Address>(bar);
                _context.Addresses.Add(addressToAdd);

            }
            else
            {
                var barInDb = _context.Bars.Single(b => b.Id == bar.Id);
                var addressInDb = _context.Addresses.Single(a => a.BarId == bar.Id);
                Mapper.Map<BarFormViewModel, Bar>(bar, barInDb);
                Mapper.Map<BarFormViewModel, Address>(bar, addressInDb);

            }
            _context.SaveChanges();

            return RedirectToAction("Index", "Bar");
        }

域名模型：

public class Bar
    {
        public int Id { get; set; }
        public string Name { get; set; }
        [Required]
        public string GooglePlaceId { get; set; }
        public string SundayDiscounts { get; set; }
        public string MondayDiscounts { get; set; }
        public string TuesdayDiscounts { get; set; }
        public string WednesdayDiscounts { get; set; }
        public string ThursdayDiscounts { get; set; }
        public string FridayDiscounts { get; set; }
        public string SaturdayDiscounts { get; set; }
        [Display(Name = "Last Updated")]
        public DateTime LastUpdated { get; set; }
    }

 public class Address
    {
        public int Id { get; set; }
        public int? Number { get; set; }
        public string StreetName { get; set; }

        public string City { get; set; }

        public string State { get; set; }
        [Required]
        public int ZipCode { get; set; }

        public Bar Bar { get; set; }
        public int BarId { get; set; }
    }

查看包含地址和栏属性的模型：

{
    public class BarFormViewModel
    {
        public int? Id { get; set; }
        public string Name { get; set; }
        [Required]
        [Display(Name = "Google Place ID")]
        public string GooglePlaceId { get; set; }
        [Display(Name = "Sunday Happy Hour Info:")]
        public string SundayDiscounts { get; set; }
        [Display(Name = "Monday Happy Hour Info:")]
        public string MondayDiscounts { get; set; }
        [Display(Name = "Tuesday Happy Hour Info:")]
        public string TuesdayDiscounts { get; set; }
        [Display(Name = "Wednesday Happy Hour Info:")]
        public string WednesdayDiscounts { get; set; }
        [Display(Name = "Thursday Happy Hour Info:")]
        public string ThursdayDiscounts { get; set; }
        [Display(Name = "Friday Happy Hour Info:")]
        public string FridayDiscounts { get; set; }
        [Display(Name = "Saturday Happy Hour Info:")]
        public string SaturdayDiscounts { get; set; }
        [Display(Name = "Last Updated")]
        public DateTime? LastUpdated { get; set; }


        //Address Model Info
        public Address Address { get; set; }
        public int? AddressId { get; set; }
        [RegularExpression("([1-9][0-9]*)", ErrorMessage = "Must be a number")]
        public int? Number { get; set; }
        public string StreetName { get; set; }

        public string City { get; set; }

        public string State { get; set; }
        [Required]
        public int? ZipCode { get; set; }

        public bool IsNew { get; set; }

    }

这里的问题是我使用此设置获取一个空的AddressId，这会在Save操作运行时导致异常。这是因为BarForm视图传递了一个已从Bar对象映射的ViewModel，而Bar域模型实际上没有Address信息，因为它不是Address model / table。

有没有办法以某种方式组合来自地址和条形模型的数据，然后将它们两个映射到同一个viewModel？

我在“保存”操作中不断为此行获取“序列包含无元素”错误：

var addressInDb = _context.Addresses.Single(a => a.Id == bar.AddressId);

我也尝试过：

var addressInDb = _context.Addresses.Single(a => a.BarId == bar.Id);

都没有工作。我理解错误说的是什么，并且还检查了我隐藏的Addressid字段的实际HTML并且它是空白的......请参阅我的BarForm视图中的代码：

 @Html.HiddenFor(m => m.Id)
    @Html.HiddenFor(m => m.AddressId)
    @Html.AntiForgeryToken()

Answer 1

删除new BarFormViewModel()作为映射调用中的第二个参数，因为它不是必需的。

在你的post动作中，在if语句中检查ModelState是否有效以及bar.Id == 0，bar是否已经是视图模型，所以不需要映射。

当您创建AutoMapper映射时，您必须创建自定义属性映射，因为Address.Id属性不会自动映射到AddressId属性，因为名称不相同。

AutoMapper.Mapper.CreateMap<Address, BarFormViewModel>()
.ForMember(dest => dest.AddressId, o => o.MapFrom(source => source.Id));

然后对逆映射执行相同操作。

ASP.NET MVC 5编辑操作 - 如何写入多个数据库表/模型

1 个答案: