我有一个索引视图,从Action链接获取参数。有时候我不会成为一个记录,在这种情况下我希望@ Model.Count只显示0.这样工作得很好。然后我需要一个按钮将相同的参数传递给Create视图,以添加新的(初始)记录并显示在上一个索引页面上。这是我遇到问题的地方。
<input class="btn btn-sm btn-info" type="button" value="Add To Roster" onclick=" location.href = '@Url.Action("Create", "Enrollments", new {enrollments_CurrentSites = Model.First().Enrollments_CurrentSite}, null)' "/>
如果没有记录,而不是显示0,我现在得到一个错误&#34;序列包含无元素&#34;。我想也许有一个null模型并试图检查它,但没有去。如果有一个或多个记录,则显示计数并且&#34;添加到名册&#34;按钮按预期执行。 有人可以帮我解决这个错误吗?
错误代码:
@model IEnumerable<SlamJammersData.Model.Enrollments>
@{
ViewBag.Title = "Rosters";
}
<div class="container-fluid">
<div class="panel panel-info">
<div class="panel-body">
<div class="container">
<div class="row">
@if (Model == null)
{
<h4>Roster count: 0</h4>
}
else
{
<p>
<h4>Roster count: @Model.Count() </h4>
</p>
}
</div>
</div>
</div>
<div class="panel-footer">
<div class="row">
<div class="col-sm-2">
<p>
<input class="btn btn-sm btn-info" type="button" value="Add To Roster" onclick=" location.href = '@Url.Action("Create", "Enrollments", new {enrollments_CurrentSites = Model.First().Enrollments_CurrentSite}, null)' "/>
</p>
</div>
<div class="col-sm-2">
<div class="col-sm-2">
<input type="button" class="btn btn-default btn-sm" value="Attendance" />
</div>
</div>
</div>
</div>
<div class="container">
<div class="row">
<div>
<table class="table table-striped table-condensed table-responsive">
<tr>
<th>Player</th>
<th>@Html.DisplayNameFor(model => model.StartTime)</th>
<th></th>
<th></th>
</tr>
@foreach(var item in Model)
{
<tr>
<td>@Html.DisplayFor(modelItem => item.FullName)</td>
<td>@Html.DisplayFor(modelItem => item.StartTime)</td>
<td>
@Html.ActionLink("Details", "Details", new{id = item.Id})
</td>
<td>
@Html.ActionLink("Edit", "Edit", new {id = item.Id})
</td>
</tr>
}
</table>
</div>
</div>
</div>
</div>
</div>
发送代码:
@Html.ActionLink("Rosters", "Index", "Enrollments", new { id = item.Id }, null) |