我在使用 List<SelectListItem>
时遇到问题.每当代码命中 foreach
它说:
object reference not set to an instance of an object.
我是不是遗漏了什么或者谁能解释为什么它在那里失败了?
public ActionResult HammerpointVideos(string category, string type)
{
var stuff = Request.QueryString["category"];
var ItemId = (from p in entities.EstimateItems
where p.ItemName == category
select p.EstimateItemId).FirstOrDefault();
var Videos = (from e in entities.EstimateVideos
where e.EstimateItemId == ItemId
select new Models.HammerpointVideoModel
{
VideoName = e.VideoName,
VideoLink = e.VideoLink
}).ToList();
var model= new Models.HammerpointVideoListModel();
List<SelectListItem> list = model.VideoList;
foreach (var video in Videos)
{
list.Add(new SelectListItem()
{
Selected=false,
Value = video.VideoLink,
Text = video.VideoName
});
}
}
最佳答案
ViedoList
之前是否初始化过?我认为不是。创建新列表向其添加项目,然后在您的模型中添加对它的引用:
var model = new Models.HammerpointVideoListModel();
List<SelectListItem> list = new List<SelectListItem>();
foreach (var video in Videos)
{
list.Add(new SelectListItem()
{
Selected=false,
Value = video.VideoLink,
Text = video.VideoName
});
}
model.VideoList = list;
关于c# - 添加新的选择列表项时对象引用错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17169119/