需要类型为 'System.Collections.Generic.IEnumerable`1 的模型项

Question

我的控制器中有一个 LINQ 查询，它有一个选择所有记录的连接。然后我将 ReportCompletionStatus.AsEnumerable() 模型传递给我的视图。但我一直收到 fowling 异常..

传入字典的模型项的类型为'System.Data.Entity.Infrastructure.DbQuery`1

但是这本词典需要一个类型为 'System.Collections.Generic.IEnumerable`1

的模型项

我正在设置模型 AsEnumerable() 并且我的观点期待@model IEnumerable 所以我仍然不确定为什么它会抱怨...

控制器

        var ReportCompletionStatus = from r in db.Report_Completion_Status
                                     join rc in db.Report_Category
                                     on r.Report_Category equals rc.ReportCategoryID
                                     select new
                                     {
                                         r.Report_Num,
                                         rc.ReportCategory,
                                         r.Report_Sub_Category,
                                         r.Report_Name,
                                         r.Report_Owner,
                                         r.Report_Link,
                                         r.Report_Description,
                                         r.Last_Published,
                                         r.Previous_Published,
                                         r.Published_By,
                                         r.Previous_Published_By,
                                         r.Last_Edited,
                                         r.Edited_By
                                     };



         return View(ReportCompletionStatus.AsEnumerable());

型号

@model IEnumerable<WebReportingTool.Report_Completion_Status>

Answer 1

使用 select new，您可以投影到匿名类型，而不是 IEnumerable<WebReportingTool.Report_Completion_Status>

您需要创建一个 ViewModel class（因为您的投影具有来自 Report_Completion_Status 和 Report_Category 的数据）并将其用于投影和视图的模型。

class

public class SomeViewModel {
  public int ReportNum {get;set;}
  public string ReportCategory {get;set;
  //etc.
}

投影

select new SomeViewModel
              {
                   ReportNum = r.Report_Num,
                   ReportCategory = rc.ReportCategory,
                   //etc.                         
              };

查看

@model IEnumerable<SomeViewModel>

顺便说一句，AsEnumerable is not necessary.

Answer 2

下面是我如何让它工作的。

型号

  public class ReportCategoryListModel
{
        public int Report_Num { get; set; }
        public string ReportCategory { get; set; }
        public string Report_Sub_Category { get; set; }
        public string Report_Name { get; set; }
        public string Report_Owner { get; set; }
        public string Report_Link { get; set; }
        public string Report_Description { get; set; }
        public Nullable<System.DateTime> Last_Published { get; set; }
        public Nullable<System.DateTime> Previous_Published { get; set; }
        public Nullable<int> Published_By { get; set; }
        public Nullable<int> Previous_Published_By { get; set; }
        public Nullable<System.DateTime> Last_Edited { get; set; }
        public Nullable<int> Edited_By { get; set; }
}

控制器

 var ReportCompletionStatus = from r in db.Report_Completion_Status
                                     join rc in db.Report_Category
                                     on r.Report_Category equals rc.ReportCategoryID
                                     select new ReportCategoryListModel
                                     {
                                         Report_Num = r.Report_Num,
                                         ReportCategory = rc.ReportCategory,
                                         Report_Sub_Category = r.Report_Sub_Category,
                                         Report_Name = r.Report_Name,
                                         Report_Owner = r.Report_Owner,
                                         Report_Link = r.Report_Link,
                                         Report_Description = r.Report_Description,
                                         Last_Published = r.Last_Published,
                                         Previous_Published= r.Previous_Published,
                                         Published_By = r.Published_By,
                                         Previous_Published_By = r.Previous_Published_By,
                                         Last_Edited = r.Last_Edited,
                                         Edited_By = r.Edited_By
                                     };

 return View(ReportCompletionStatus);

查看

@model IEnumerable<WebReportingTool.Models.ReportCategoryListModel>

需要类型为 'System.Collections.Generic.IEnumerable`1 的模型项

Requires a model item of type 'System.Collections.Generic.IEnumerable`1

linq

asp.net-mvc

ienumerable