c# - ASP.Net C# MVC 组域模型并将结果放入 ViewModel

Question

我想从我的域模型中选择某些字段，并按域模型中的一个字段进行分组，然后将结果放入 ViewModel - 但是，我无法正确获取 Linq 语法。

我的模型是：

public class Offer
{
    public int OfferId { get; set; }
    public string Inclusions { get; set; }
    public string Property { get; set; }
    public bool IncludeInOffer { get; set; }
    public Guid guid { get; set; }
    public int NumPeople { get; set; }
    public int NumNights { get; set; }
    public DateTime ArrivalDate { get; set; }
    public string CustomerName { get; set; }
    public string EmailAddress { get; set; }
    public DateTime OfferCreatedOn { get; set; }
    public string Email { get; set; }
    public string OfferReference { get; set; }

     }

我的视图模型是：

 public class OfferVMList
{
    public string guid { get; set; }
    public int NumPeople { get; set; }
    public int NumNights { get; set; }
    public DateTime ArrivalDate { get; set; }
    public string CustomerName { get; set; }
    public string EmailAddress { get; set; }
    public DateTime OfferCreatedOn { get; set; }
    public string Email { get; set; }
    public string OfferReference { get; set; }
}

我的 Linq 是：

 OfferVMList item = db.Offers
        .GroupBy(x => x.OfferReference)
        .Select(ct => new OfferVMList
        {
            NumPeople = ct.NumPeople           
        })
        .OrderBy(x => x.ArrivalDate);

但是，错误消息是：

System.Linq.IGrouping<string,FGBS.Models.Offer>' does not contain a definition for 'NumPeople' and no extension method 'NumPeople' accepting a first argument of type 'System.Linq.IGrouping<string,FGBS.Models.Offer>' could be found (are you missing a using directive or an assembly reference?)'

谁能看到我要去哪里错了？

谢谢

Answer 1

检查这个：

var item = db.Offers
        .OrderBy(x => x.ArrivalDate);
        .GroupBy(x => x.OfferReference)
        .Select(ct => ct.Select(x => new OfferVMList {
            NumPeople = x.NumPeople
        });