C# 传递的模型项与预期的IEnumerable不匹配
我正在为学校建一个项目。我就快到了,但有一个错误我无法纠正。 我正在asp.net网站上预订自行车。 错误是我将一个列表传递到保留的索引页,它需要一个IEnumerable。 我已经试着制作一个预期的列表,但这也给出了一个错误 我已经看到这个问题的其他修复方法,但我无法让它工作 这是我最初的索引方法C# 传递的模型项与预期的IEnumerable不匹配,c#,asp.net,asp.net-mvc,database,entity-framework,C#,Asp.net,Asp.net Mvc,Database,Entity Framework,我正在为学校建一个项目。我就快到了,但有一个错误我无法纠正。 我正在asp.net网站上预订自行车。 错误是我将一个列表传递到保留的索引页,它需要一个IEnumerable。 我已经试着制作一个预期的列表,但这也给出了一个错误 我已经看到这个问题的其他修复方法,但我无法让它工作 这是我最初的索引方法 // GET: Reservations public ActionResult Index() { var reservations = db.Reserv
// GET: Reservations
public ActionResult Index()
{
var reservations = db.Reservations.Include(r => r.Bike).Include(r => r.Customer).Include(r => r.DropoffStore).Include(r => r.PickupStore);
return View(reservations.ToList());
}
这是我从其他人那里得到的新控制器索引方法,但我不知道为什么我不工作:
// GET: Reservations
public ActionResult Index()
{
var reservations = db.Reservations.Include(r => r.Bike).Include(r => r.Customer).Include(r => r.DropoffStore).Include(r => r.PickupStore);
IEnumerable<ReservationViewModel> reservationViewModels = new List<ReservationViewModel>();
foreach (var reservation in reservations)
{
var reservationViewModel = new ReservationViewModel
{
};
reservationViewModels.ToList().Add(reservationViewModel);
}
return View(reservationViewModels);
}
我的整个预订视图模型:
using ASP.NET_Framwork_for_real_bitch.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Web;
using System.Web.Mvc;
namespace ASP.NET_Framwork_for_real_bitch.ViewModels
{
public class ReservationViewModel
{
private BikeShoppaModel db = new BikeShoppaModel();
public Reservation Reservation { get; set; }
public SelectList DropoffStore_Id { get; private set; }
public SelectList PickupStore_Id { get; private set; }
public SelectList Bikes { get; private set; }
public SelectList CustomerGender { get; set; }
public int TotalDays { get; set; }
public double TotalPrice { get; set; }
public ReservationViewModel()
{
DropoffStore_Id = new SelectList(db.Stores, "Id", "StoreName");
PickupStore_Id = new SelectList(db.Stores, "Id", "StoreName");
Bikes = new SelectList(db.Bikes, "Id", "Brand");
CustomerGender = new SelectList(db.Customers, "Id", "Gender");
}
public ReservationViewModel(int id) : this()
{
Reservation = db.Reservations.Find(id);
TotalDays = (Reservation.EndDate.Date - Reservation.StartDate.Date).Days + 1;
}
public void Save()
{
if(Reservation.Id > 0)
{
db.Entry(Reservation).State = EntityState.Modified;
}
else
{
db.Reservations.Add(Reservation);
}
db.SaveChanges();
}
}
}
我的预订模式:
public class Reservation
{
public int Id { get; set; }
[ForeignKey("Customer")]
[Display(Name = "Customer")]
public int Customer_Id { get; set; }
public virtual Customer Customer { get; set; }
[ForeignKey("Bike")]
public int Bike_Id { get; set; }
public Bike Bike { get; set; }
[DataType(DataType.Date)]
[Column(TypeName = "Date")]
[Display(Name = "Start date")]
public DateTime StartDate { get; set; }
[DataType(DataType.Date)]
[Column(TypeName = "Date")]
[Display(Name = "End date")]
public DateTime EndDate { get; set; }
[ForeignKey("PickupStore")]
[Display(Name = "Pickup store")]
public int PickupStore_Id { get; set; }
public Store PickupStore { get; set; }
[ForeignKey("DropoffStore")]
[Display(Name = "Dropoff store")]
public int DropoffStore_Id { get; set; }
public Store DropoffStore { get; set; }
}
在控制器索引方法中返回保留列表。您的视图需要一个IEnumerable的ReservationViewModels。因此,您的控制器生成苹果,但您的视图需要桔子。 因此,你必须把苹果变成橘子来实现这一目标——作为一名软件开发人员,这是实现这一目标的几个优势之一:-) 试着这样做:
var reservations = db.Reservations.Include(r => r.Bike).Include(r => r.Customer).Include(r => r.DropoffStore).Include(r => r.PickupStore);
IEnumerable<ReservationViewModel> reservationViewModels = new List<ReservationViewModel>();
foreach (var reservation in reservations)
{
var reservationViewModel = new ReservationViewModel
{
OneProperty = reservation.AnotherProperty
//... other properties you need to convert ...
}
reservationViewModels.Add(reservationViewModel);
}
return View(reservationViewModels);
var reservations=db.reservations.Include(r=>r.Bike)。Include(r=>r.Customer)。Include(r=>r.DropoffStore)。Include(r=>r.PickupStore);
IEnumerable reservationViewModels=新列表();
foreach(保留中的var保留)
{
var reservationViewModel=新的reservationViewModel
{
OneProperty=reservation.AnotherProperty
//…需要转换的其他属性。。。
}
添加(reservationViewModel);
}
返回视图(reservationViewModels);
因此,您必须迭代您的苹果(保留类型的对象),并为每个苹果生成一个橙色(保留类型的对象ViewModel)。最后,您将这组橙子(IEnuerable of ReservationViewModel=传递给您的视图和您的完成。请将控制器索引操作方法替换为以下方法,并发表您的评论:
// GET: Reservations
public ActionResult Index()
{
var reservations = db.Reservations.Include(r => r.Bike).Include(r => r.Customer).Include(r => r.DropoffStore).Include(r => r.PickupStore);
var reservationViewModels = new List<ReservationViewModel>();
foreach (var reservation in reservations)
{
var reservationViewModel = new ReservationViewModel
{
};
reservationViewModels.Add(reservationViewModel);
}
/*
// In short you can populate your viewmodels and return as below:
return (reservations.Select(r => new ReservationViewModel{
}).AsEnumerable());
*/
return View(reservationViewModels.AsEnumerable());
}
//获取:预订
公共行动结果索引()
{
var reservations=db.reservations.Include(r=>r.Bike).Include(r=>r.Customer).Include(r=>r.DropoffStore).Include(r=>r.PickupStore);
var reservationViewModels=新列表();
foreach(保留中的var保留)
{
var reservationViewModel=新的reservationViewModel
{
};
添加(reservationViewModel);
}
/*
//简而言之,您可以按如下方式填充viewmodels并返回:
return(reservations.Select(r=>newreservationviewmodel{
}).AsEnumerable());
*/
返回视图(reservationViewModels.AsEnumerable());
}
附带说明:您基本上混淆了实体模型和视图模型。它需要大量的清理和/或重构。您需要将模型中的
Reservation
转换为视图模型中的ReservationViewModel
。您可以使用Automapper或extension方法来实现这一点。您能澄清一下吗?我对索引中的asp.net非常陌生ode>发送到Reservation
实体的视图集合的操作,但在视图中引用了一个集合ReservationViewModel
。因此两个对象不同。您有两种解决方案:1-在操作中将Reservation
的集合转换为ReservationViewModel
的集合,并将其发送到视图。2-在视图中直接使用Reservation
实体。我建议使用第一种。它在Stackoverflow(以及其他地方)上被证明是一种很好的样式,但这在这里太过分了,无法响应注释和帮助。reservationViewModels.Add(reservationViewModel);给出了一个错误,它不包含add的定义。作为属性,我需要添加模型中的每个属性吗?检查拼写错误,列表有一个add方法(是否键入小写?)。只有那些您希望在视图中使用的属性。其他属性将保留其默认值(如0表示int或null表示字符串)。
var reservations = db.Reservations.Include(r => r.Bike).Include(r => r.Customer).Include(r => r.DropoffStore).Include(r => r.PickupStore);
IEnumerable<ReservationViewModel> reservationViewModels = new List<ReservationViewModel>();
foreach (var reservation in reservations)
{
var reservationViewModel = new ReservationViewModel
{
OneProperty = reservation.AnotherProperty
//... other properties you need to convert ...
}
reservationViewModels.Add(reservationViewModel);
}
return View(reservationViewModels);
// GET: Reservations
public ActionResult Index()
{
var reservations = db.Reservations.Include(r => r.Bike).Include(r => r.Customer).Include(r => r.DropoffStore).Include(r => r.PickupStore);
var reservationViewModels = new List<ReservationViewModel>();
foreach (var reservation in reservations)
{
var reservationViewModel = new ReservationViewModel
{
};
reservationViewModels.Add(reservationViewModel);
}
/*
// In short you can populate your viewmodels and return as below:
return (reservations.Select(r => new ReservationViewModel{
}).AsEnumerable());
*/
return View(reservationViewModels.AsEnumerable());
}