制造层叠的DropDownList [英] making cascading dropdownlist
问题描述
我试图使 ASP.NET MVC4 级联下拉列表中，为我的下拉列表中的两个值来从方法，所以我在急难如何通过价值形成一个下拉列表到另一个。
I am trying to make cascading dropdown list in ASP.NET MVC4, both values for my dropdown list's comes from methods, so am in trouble how to pass value form one dropdown list to another.
下面就是我得到的第一个下拉列表值：
Here's how I get values for the first dropdown list:
var CampaignInfo1 = CampaignManagementService.GetAdvertisers((string)Session["ticket"]);
List<CampaignList1> items1 = new List<CampaignList1>();
foreach (var element in CampaignInfo1)
{
items1.Add(new CampaignList1() { ID1 = element.Key, Name1 = element.Value });
}
var listOfCamp1 = new SelectList(items1, "ID1", "Name1", 1);
ViewData["list1"] = listOfCamp1;
和视图中的下拉列表：
@Html.DropDownList("list1", ViewData["list1"] as SelectList, "-- Select Client -1-")
第二个下拉列表值我得到几乎相同的方式：
The second dropdown list value am getting almost same method:
var CampaignInf = CampaignManagementService.GetCampaigns((string)Session["ticket"], IDFromfirstDDL);
List<AlreadyCreatedCampaignList> itemas = new List<AlreadyCreatedCampaignList>();
foreach (var element in CampaignInf)
{
itemas.Add(new AlreadyCreatedCampaignList() { campID = element.Key, campName = element.Value });
}
var listOfCam = new SelectList(itemas, "campID", "campName", 1);
ViewData["clist"] = listOfCam;
但是，在方法GetCampaigns我要通过我从第一DDL获得ID（IDFromfirstDDL），然后才是方法的返回值，这是该ID的一个问题。
问题是，我不知道如何选定值从第一DDL第二传，没有任何形式提交，因为我需要一个第二DDL后第一DDL变化立即改变了他的价值。
But there is a problem that in method GetCampaigns I have to pass the id(IDFromfirstDDL) which I get from first DDL, and only then method return values which are for that id. The problem is that I don't know how to pass that selected value from first DDL to second, without any form submit, because I need that second DDL changes his values immediately after first DDL changes.
推荐答案
我做到了结合的 http://kruisit.nl/articles/asp.net-mvc-linked-dropdown/ 和的 http://www.appelsiini.net/projects/chained jQuery的链接选择这篇文章
i made it combining http://kruisit.nl/articles/asp.net-mvc-linked-dropdown/ and http://www.appelsiini.net/projects/chained jquery chained selector this article
目前使用我的网站
public static class LinkedDropdownHelper
{
#region Methods
public static MvcHtmlString LinkedDropdownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, string parent, IEnumerable<LinkedSelectListItem> selectList ,bool removedefault=false)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression( expression,htmlHelper.ViewData );
var selectedvalue = metadata.Model;
string propertyName = metadata.PropertyName;
TagBuilder select = new TagBuilder("select");
select.Attributes.Add("id", propertyName);
select.Attributes.Add("name", propertyName);
//select.Attributes.Add("class", "linked-dropdown");
select.Attributes.Add("class", parent);
foreach (var item in selectList)
{
if (removedefault && item.Value == "-1")
{
//skip default
}
else
{
TagBuilder option = new TagBuilder("option");
option.InnerHtml = item.Text;
option.Attributes.Add("value", item.Value);
option.Attributes.Add("class", item.LinkValue);
if (item.Selected)
{
option.Attributes.Add("selected", "selected");
}
select.InnerHtml += option.ToString(TagRenderMode.Normal);
}
}
//below code was changed by abdurrauf to support jquery chains
string script = @"<script type='text/javascript'>$(document).bind('ready', function(){
$('#" + propertyName + "').chained('#" + parent + "');"+
@"$('select[name=""" + propertyName + @"""]').val("""+selectedvalue+@""");" +
"});</script>";
return MvcHtmlString.Create(script + select.ToString(TagRenderMode.Normal));
}
#endregion Methods
}
public class LinkedSelectList : IEnumerable<LinkedSelectListItem>
{
#region Constructors
public LinkedSelectList(IEnumerable items, string dataValueField, string dataTextField, string dataLinkedValueField, IEnumerable selectedValues)
{
if (items == null)
{
throw new ArgumentNullException("items");
}
Items = items;
DataValueField = dataValueField;
DataTextField = dataTextField;
DataLinkedValueField = dataLinkedValueField;
SelectedValues = selectedValues;
}
#endregion Constructors
#region Properties
public string DataLinkedValueField
{
get; private set;
}
public string DataTextField
{
get; private set;
}
public string DataValueField
{
get; private set;
}
public IEnumerable Items
{
get; private set;
}
public IEnumerable SelectedValues
{
get; private set;
}
#endregion Properties
#region Methods
public virtual IEnumerator<LinkedSelectListItem> GetEnumerator()
{
return GetListItems().GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
internal IList<LinkedSelectListItem> GetListItems()
{
return GetListItemsWithValueField();
}
private static string Eval(object container, string expression)
{
object value = container;
if (!String.IsNullOrEmpty(expression))
{
value = DataBinder.Eval(container, expression);
}
return Convert.ToString(value, CultureInfo.CurrentCulture);
}
private IList<LinkedSelectListItem> GetListItemsWithValueField()
{
HashSet<string> selectedValues = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
if (SelectedValues != null)
{
selectedValues.UnionWith(from object value in SelectedValues select Convert.ToString(value, CultureInfo.CurrentCulture));
}
var listItems = from object item in Items
let value = Eval(item, DataValueField)
select new LinkedSelectListItem
{
Value = value,
Text = Eval(item, DataTextField),
LinkValue = Eval(item, DataLinkedValueField),
Selected = selectedValues.Contains(value)
};
return listItems.ToList();
}
#endregion Methods
}
public class LinkedSelectListItem
{
#region Properties
public string LinkValue
{
get; set;
}
public bool Selected
{
get; set;
}
public string Text
{
get; set;
}
public string Value
{
get; set;
}
#endregion Properties
}
这篇关于制造层叠的DropDownList的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
