C# ASP.Net MVC 添加项目到绑定下拉列表
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ASP.Net MVC Add Items To Bound Dropdownlist
提问by Gavin
My page view currently has a dropdownlist on it that is getting bound to a collection from the controller. This is working fine, However I want to insert an item to the top of the dropdownlist that is not in my collection e.g the list currently gets the following items
我的页面视图目前有一个下拉列表，它绑定到控制器的集合。这工作正常，但是我想在下拉列表的顶部插入一个不在我的集合中的项目，例如列表当前获取以下项目
Open
Closed
I want to add a third option of "All" but I don't want to add this option to my database. In Webforms I would have just bound the control then inserted another item however it seems this is not possible with MVC, am I right in thinking I will need to add some Javascript to the view to add this new item once the dropdownlist has been bound?
我想添加“全部”的第三个选项，但我不想将此选项添加到我的数据库中。在 Webforms 中，我只是绑定了控件然后插入了另一个项目，但是似乎这在 MVC 中是不可能的，我是否认为我需要在视图中添加一些 Javascript 以在绑定下拉列表后添加这个新项目？
Thanks
谢谢
采纳答案by tvanfosson
No. Construct your data as a list of SelectListItems and prepend in the controller.
不。将您的数据构建为 SelectListItems 列表并在控制器中添加。
var list = db.Table
.Select( t => new SelectListItem
{
Key = t.ID.ToString(),
Value = t.Name
} )
.ToList();
list.Insert( 0, new SelectListItem { Key = "-1", Value = "All" } );
ViewData["TableSelect"] = list;
On the view side:
在视图方面：
<%= Html.DropDownList( "TableID",
(IEnumerable<SelectListItem>)ViewData["TableSelect"] ) %>
回答by Vikas
Simple
简单的
you can make it as you wish in controller.
您可以在控制器中随心所欲地制作它。
and pass it in viewdata.
并在视图数据中传递它。
other option is directly in view page.
其他选项直接在视图页面中。
<%= Html.DropDownList("DropDown","all" )%>
But you can add only one option..
但是您只能添加一个选项..
Make sure you are not storing added options in ur db, right? so before you save it, check option value in action and apply your logic.
确保您没有在您的数据库中存储添加的选项，对吗？因此，在保存之前，请检查操作中的选项值并应用您的逻辑。
回答by Denis Cilliers
Newer implementation
较新的实现
var list = _db.Status.ToList();
list.Add(new Status(){DevelopmentStatusID = -1, DevelopmentStatusDesc = "All"});
var result = list.OrderBy(d => d.StatusID).ToList();
ViewBag.StatusID = new SelectList(result, "StatusID", "StatusDesc");
Then in the index.html
然后在 index.html
@Html.DropDownList("StatusID", null, htmlAttributes: new {@class = "form-control"})
