从ViewBag中选择TagHelper使用List

Question

我目前正在尝试在asp.net 5中使用taghelpers.我想使用带有ViewBag列表的select标签帮助器.我放入asp-for字段的任何内容都会给我一个错误,因为它试图从IEnumerable而不是视图包中取出它.

我想替换这个:

@model IEnumerable<InvoiceIT.Models.Invoice>
@using (Html.BeginForm())
{
    <p>            
        @Html.DropDownList("Companies", String.Empty)       
        <input type="submit" value="Filter" class="btn btn-default" />
    </p>
}

有了这个:

@model IEnumerable<InvoiceIT.Models.Invoice>
<form asp-controller="Invoice" asp-action="Index" method="post" class="form-horizontal" role="form">
    <select asp-for="????" asp-items="ViewBag.Companies" class="form-control">
    </select>
    <input type="submit" value="Save" class="btn btn-default" />
</form>

以下是我如何填充控制器中的选择列表:

ViewBag.Companies = new SelectList(await DbContext.Company.ToListAsync(), "CompanyID", "Name");

Answer 1

如果您不希望该asp-for属性Model直接从中拉出,则可以通过提供一个来覆盖该行为@.

又名:

<select asp-for="@ViewBag.XYZ">
    ...
</select>

因此,基于你所说的我相信你的位成为:

@model IEnumerable<InvoiceIT.Models.Invoice>
<form asp-controller="Invoice" asp-action="Index" method="post" class="form-horizontal" role="form">
@{
    SelectList companies = ViewBag.Companies;
    var currentlySelectedIndex = 0; // Currently selected index (usually will come from model)
}
    <select asp-for="@currentlySelectedIndex" asp-items="companies" class="form-control">
    </select>
    <input type="submit" value="Save" class="btn btn-default" />
</form>

希望这有帮助!