如何修复"Cannot implicitly convert type Generic.IEnumerable<type>' to 'Generic.List<type>"

Question

为什么我会收到这个错误消息：

无法将类型"System.Collections.Generic.IEnumerable"隐式转换为"System.Collections.Generic.List"

当我构建这个代码时：

 List<BALHotelList> searchresult=from a in bh
                join b in hr on a.HotelCode equals b.hotelCode
                orderby a.HotelName
                select new BALHotelList
                    {
                       HotelCode= a.HotelCode,
                       ImageURL_Text = a.ImageURL_Text,
                       HotelName = a.HotelName,
                       StarRating = a.StarRating,
                       HotelAddress = a.HotelAddress,
                       Destination = a.Destination,
                       Country = a.Country,
                       HotelInfo = a.HotelInfo,
                       Latitude = a.Latitude,
                       Longitude = a.Longitude,
                       totalPrice = b.totalPrice,
                       totalPriceSpecified = b.totalPriceSpecified,
                       totalSalePrice = b.totalSalePrice,
                       totalSalePriceSpecified = b.totalSalePriceSpecified,
                       rooms = b.rooms
                    };

Answer 1

从LINQ语句返回的类型是IEnumerable，而不是List。

如果你真的必须把它作为一个列表，那么把（）放在整个"From a in….to select new xxx｛｝；"周围，然后首先对结果调用ToList（）。

否则，执行"var searchresult=…."，您仍然可以对"searchresult"变量进行foreach。

Answer 2

您可能只需要用一些括号包装您的linq，然后调用结果上的.ToList：

List<BALHotelList> searchresult= (from a in bh
            join b in hr on a.HotelCode equals b.hotelCode
            orderby a.HotelName
            select new BALHotelList
                {
                   HotelCode= a.HotelCode,
                   ImageURL_Text = a.ImageURL_Text,
                   HotelName = a.HotelName,
                   StarRating = a.StarRating,
                   HotelAddress = a.HotelAddress,
                   Destination = a.Destination,
                   Country = a.Country,
                   HotelInfo = a.HotelInfo,
                   Latitude = a.Latitude,
                   Longitude = a.Longitude,
                   totalPrice = b.totalPrice,
                   totalPriceSpecified = b.totalPriceSpecified,
                   totalSalePrice = b.totalSalePrice,
                   totalSalePriceSpecified = b.totalSalePriceSpecified,
                   rooms = b.rooms
                }).Tolist();

Answer 3

如果您想要一个列表，您需要将Linq查询封装在括号中并调用.ToList()。