我编写了以下方法来填充DropDownList,它可以工作。但是,我想使用 Lambda 表达式作为 SelectList 初始值设定项的第一个参数而不是那里的推导查询来编写正确的 LINQ 查询。我的目标是连接 Eventm 对象的 EventmId 和 EventmTitle 属性,以在 DropDownList 中显示为选择。
谢谢!
private void PopulateEventmsDropDownList(object selectedEventm = null)
{
var eventmsQuery = unitOfWork.EventmRepository.Get(
orderBy: q => q.OrderBy(d => d.EventmId));
ViewBag.EventmID = new SelectList(
(from s in eventmsQuery select new { EventmId = s.EventmId.ToString(),
FullID = s.EventmId + " " + s.EvtTitle }),
"EventmId", "FullID", selectedEventm);
}
在使用 LINQPad 进行一些试验和错误之后,我在 SelectList 中提出了这个 Lambda 表达式(以替换理解查询),如下所示:
private void PopulateEventmsDropDownList(object selectedEventm = null)
{
var eventmsQuery = unitOfWork.EventmRepository.Get(
orderBy: q => q.OrderBy(d => d.EventmId));
ViewBag.EventmID = new SelectList(nodesQuery.Select(
x => new {x.NodeId, FullID = string.Join(
" ", x.NodeId.ToString(), x.Title) }), "EventmId", "FullID", selectedEventm);
}