Question

我有一个LINQ查询，它返回与我的PictureGallery类匹配的结果。我需要将它们加载到我的ViewModel中，但我收到以下错误：

无法隐式转换类型 'System.Linq.IQueryable'来 'System.Collections.Generic.IEnumerable'。存在显式转换（您是否错过了演员？）

我是C＃的新人。如何将“结果”投射到我的“PictureGallery”viewmddel类中？

提前致谢！

控制器：

//Test MediaID
var MediaID = 75;

//Query Results
var Results = from g in DB.Galleries
              join m in DB.Media on g.GalleryID equals m.GalleryID
              where g.GalleryID == GalleryID
              orderby m.MediaDate descending, m.MediaID descending
              select new { g.GalleryTitle, Media = m };

//Create my viewmodel
var Model = new GalleryViewModel
{
    MediaID = MediaID,
    PictureGallery = Results, //This line throws the error.
    PictureCount = Results.Count()
};

的ViewModels：

public class GalleryViewModel
{
    public int? MediaID { get; set; }
    public IEnumerable<PictureGallery> PictureGallery { get; set; }
    public int PictureCount { get; set; }
}

public class PictureGallery
{
    public int GalleryID { get; set; }
    public string GalleryTitle { get; set; }
    public int MediaID { get; set; }
    public string MediaTitle { get; set; }
    public string MediaDesc { get; set; }
    public double Rating { get; set; }
    public int Views { get; set; }
}

Answer 1

将您的查询改为：

//Query Results
var Results = from g in DB.Galleries
              join m in DB.Media on g.GalleryID equals m.GalleryID
              where g.GalleryID == GalleryID
              orderby m.MediaDate descending, m.MediaID descending
              select new PictureGallery {
                                GalleryID = g.GalleryId,
                                GalleryTitle = g.GalleryTitle,
                                MediaID = m.MediaID,
                                MediaTitle = m.MediaTitle,
                                MediaDesc = m.MediaDesc,
                                Rating = m.Rating,
                                Views = m.Views} ;

Answer 2

您正尝试将IEnumerable<PictureGallery>设置为IQueryable<anonymous>。您需要转换为正确的类型：

var Model = new GalleryViewModel
{
    MediaID = MediaID,
    PictureGallery = Results
        .Select(r => new PictureGallery {
            GalleryID = r.Media.GalleryID,
            GalleryTitle = r.GalleryTitle,
            MediaID = r.Media.MediaID,
            ... // and so on
        }),
    PictureCount = Results.Count()
};

Answer 3

然后你可以写 var list = result.ToList（）;

然后将它传递给这样的视图 return View（list）;

您可以在此视图中接受它 @model List

其中ViewModel是一个简单类，其属性可在查询执行后接受结果值。

您可以查看这些附件[Linq查询，查看模型，查看enter image description here ][1]

如何将这些LINQ结果加载到我的ViewModel类中？

3 个答案: