c# - asp.net mvc foreach 多对多过滤器

Question

我的代码在视图中：

@foreach (var item in Model._games)
    {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.Title)
            </td>

            <td>
                @foreach (var item2 in Model._days.Where(x => x.Games.Any(u=> u.Id == item.Id)))
                {
                    @item2.CutOffTime;
                }
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Price)
            </td>
            <td>
            </td>
        </tr>
    }

显示第二个 foreach 并像我一样过滤它的正确方法是什么？如果我不过滤（仅使用Model._days，它会显示所有天数，但是当我使用带 ID 的 Where 过滤器时，正如您在第二个 foreach 中看到的那样，它不会显示任何内容。

谢谢

Answer 1

Possible issues:
1. You're using deferred loading and forgot to populate .Games property of Model._days by using of Include method (EF) or LoadWith (LINQ 2 SQL)
2. Games is empty
3. Games is not empty but you've set an incorrect filter
4. You've populated either Model._games or Model._days.Games with incorrect data

Troubleshooting: set a breakpoint at the second foreach and see what actual values do you have in both collections.

Answer 2

• 将您的第二个 foreach 更改为

   @foreach (var item2 in Model._days)
   {
     if(item2.Games.select(e=>e.Id).Cotains(item.Id)
    {
       @item2.CutOffTime;
    }
   }