Question

我有两张桌子：

Category
=========
Id
Name 


Entry
=======
Title
Name
Username
Password
CategoryId.

所以我希望输出为列出的所有条目，但最后是Category.Name。 EX。

ID    Title     Name           Username     Password     Category
===   =====     ========       =========    =========    ===========
1     Facebook  Peter Batman   123456       Social        Network

所以我有一个返回列表的Index方法：

public ActionResult Index()
    {
       IEnumerable<ListAllEntriesViewModel> query = null;
        query = (from cat in _db.Categories
                 join en in _db.Entries on cat.Id equals en.CategoryId
                 select new
                 {
                     Id = cat.Id,
                     Title = en.Title,
                     Username = en.Username,
                     Password = en.Password,
                     Url = en.Url,
                     Description = en.Description,
                     CategoryName = cat.Name
                 }).AsEnumerable();

        return View(query);
    }

我无法将其转换为IEnumerable。有一个错误无法解决问题：

 Error  1   Cannot implicitly convert type    
'System.Collections.Generic.IEnumerable<AnonymousType#1>' to 
'System.Collections.Generic.IEnumerable<eManager.Web.Models.ListAllEntriesViewModel>'. 
 An explicit   conversion exists (are you missing a cast?)

任何帮助？

Answer 1

这样你需要添加ListAllEntriesViewModel，因为在你的代码中，类型是匿名的，所以进行更改，如下面的代码所示： -

query = (from cat in _db.Categories
                 join en in _db.Entries on cat.Id equals en.CategoryId
                 select new ListAllEntriesViewModel
                 {
                     Id = cat.Id,
                     Title = en.Title,
                     Username = en.Username,
                     Password = en.Password,
                     Url = en.Url,
                     Description = en.Description,
                     CategoryName = cat.Name
                 }).AsEnumerable();

Answer 2

正如错误所示，您正在返回一个匿名类型的IEnumerable，而不是您的Viewmodel。假设您的viewmodel具有所有必需的属性，则需要在select中创建一个新的ListAllEntriesViewModel。

query = (from cat in _db.Categories
                 join en in _db.Entries on cat.Id equals en.CategoryId
                 select new ListAllEntriesViewModel()
                 {
                     Id = cat.Id,
                     Title = en.Title,
                     Username = en.Username,
                     Password = en.Password,
                     Url = en.Url,
                     Description = en.Description,
                     CategoryName = cat.Name
                 });

如何在View MVC4中显示相关表格中的数据？

2 个答案: