c# - 为一个元素而不是其他元素过滤 SelectList

Question

所以我在前端有这个：

<%= Html.DropDownListFor(m => m.FixedComponent.PaymentBusinessDayConvention, DropDownData.BusinessDayConventionList(), "", new { @class = "DontShrink", propertyName = "FixedComponent.PaymentBusinessDayConvention", onchange = "UpdateField(this);" })%>

在DropDownData.BusinessDayConventionList()这里定义：

public static SelectList BusinessDayConventionList()
        {
            return ListBuilder(
                BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.Following),
                BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.ModifiedFollowing),
                BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.Preceding),
                BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.Unadjusted));
        }

我想删除BusinessDayConvention.Unadjusted一个 HTML Helper 的选项，而不是页面上所有其他的选项。我怎样才能干净地做到这一点？

谢谢！

Answer 1

在方法中包含一个参数：

    public static SelectList BusinessDayConventionList(bool includeUnadjusted)
    {
       var list = ListBuilder(
            BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.Following),
            BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.ModifiedFollowing),
            BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.Preceding));

       if (includeUnadjusted)
       {
         list.Items.Add(BusinessDayConventionHelper.GetFriendlyName(BusinessDayConvention.Unadjusted))
       }

       return list.
    }

您还可以使用重载来传递默认值：

    public static SelectList BusinessDayConventionList()
    {
       return BusinessDayConventionList(true);
    }