Question

对不起，我真的不知道怎么称呼它。我有一个显示公告的网页。我似乎无法弄清楚是否有任何公告，如果有显示说＆＃34;没有公告＆＃34;。

我尝过这样的话：

Because my first approach was to do that inside an Infrastructure layer/lib which listen to the events from the job layer

但这不起作用。我在哪里处理这些事情？视图/控制器？

查看：

if(db.Announcements.toArray().length == 0){
    return View(null);
}

控制器：

    @model IEnumerable<Remake.Models.Announcement>

@{
    ViewBag.Title = "Announcements";
}

<h2>Announcements</h2>

@if (User.Identity.IsAuthenticated)
{ <p>
        @Html.ActionLink("Create New", "Create")
    </p>

    <table class="table">
        <tr>
            <th>
                <b> @Html.DisplayNameFor(model => model.Title)</b>
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Content)
            </th>
            <th width="10%">
                @Html.DisplayName("Date")
            </th>

            <th></th>
        </tr>

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

                <td>
                    @Html.ActionLink("Edit", "Edit", new { id = item.AnnouncementId }) |
                    @Html.ActionLink("Comments", "Details", new { id = item.AnnouncementId }) |
                    @Html.ActionLink("Delete", "Delete", new { id = item.AnnouncementId })
                </td>
            </tr>
        }

    </table>

}
else
{
    <p>Please sign in to create an Announcement</p>
}

Answer 1

由于您的模型定义为IEnumerable<Announcement>，因此您只需使用Any()检查其是否为空：

@if (Model.Any())
{
    // show announcements
    foreach (var item in Model)
    {
        // ...
    }
}
else
{
    // show message when empty
    <p>No announcements</p>
}

请参阅MSDN

如何检查View是否未收到任何结果

1 个答案: