从包含国家/地区的XML文件生成选择列表(IEnumerable),使用DropDownListFor,不会设置模型中提供的选定值
public static IEnumerable<SelectListItem> CountrySelectList()
{
var sRetVal = new List<SelectListItem>();
string CachKey = "MVCXMLCountryList" + GetCulture();
if (HttpContext.Current.Cache[CachKey] == null | 1 == 1)
{
string xmlFile = Path.Combine(HttpContext.Current.Server.MapPath("~"), "Countries.xml");
XmlDocument Doc = new XmlDocument();
Doc.Load(xmlFile);
foreach (XmlNode Node in Doc.SelectNodes(String.Format("//Countries/language[@iso=\"{0}\"]/country", GetCulture())))
{
var tmpSelect = new SelectListItem();
tmpSelect.Value = Node.Attributes["iso2"].InnerText.ToString();
tmpSelect.Text = Node.Attributes["name"].InnerText;
tmpSelect.Selected = false;
sRetVal.Add(tmpSelect);
}
sRetVal.Sort(CountrySort);
var prioritet = new string[] {"de","fo","se","no","dk"};
switch (GetCulture())
{
case "dk": prioritet = new string[] {"de","fo","se","no","dk"}; break;
default: prioritet = new string[] { "de", "se", "no", "dk", "gb" }; break;
}
foreach (string Country in (string[])prioritet)
{
selectedCountry = Country;
var tmpSel = sRetVal.Find(FindCurrentSelected);
sRetVal.RemoveAt(sRetVal.FindIndex(FindCurrentSelected));
sRetVal.Insert(0, tmpSel);
}
//sRetVal[10].Selected = true;
HttpContext.Current.Cache[CachKey] = sRetVal;
}
else
{
sRetVal = (List<SelectListItem>)HttpContext.Current.Cache[CachKey];
}
return (IEnumerable<SelectListItem>) sRetVal;
}
尝试过两者:
@Html.DropDownListFor(model => model.Country, new SelectList(CommonHelpers.CountrySelectList(), "Value", "Text", Model.Country), "---Select---")
和
@Html.DropDownListFor(model => model.Country, CommonHelpers.CountrySelectList(), "---Select---")
任何想法?
答案 0 :(得分:1)
模型属性(Country)和显式传入的SelectList需要具有不同的名称来连接所选项。如果未提供选定值,则浏览器默认为SelectList中的第一个元素。这是DropDownList助手的已知限制。 我正在完成一个DDL教程。您可以在http://code.msdn.microsoft.com/Using-the-DropDownList-67f9367d获取完整的代码 给我发一封电子邮件,我会发给你教程.Rick.Anderson [at] microsoft.com
答案 1 :(得分:0)
您需要将“Country”值传递给您的方法,然后检查所选值
public static IEnumerable<SelectListItem> CountrySelectList(string countryId)
{
var sRetVal = new List<SelectListItem>();
// .......................
foreach (XmlNode Node in Doc.SelectNodes(String.Format("//Countries/language[@iso=\"{0}\"]/country", GetCulture())))
{
var tmpSelect = new SelectListItem();
tmpSelect.Value = Node.Attributes["iso2"].InnerText.ToString();
tmpSelect.Text = Node.Attributes["name"].InnerText;
// Check for selected value
tmpSelect.Selected = string.Equals(tmpSelect.Value, countryId);
sRetVal.Add(tmpSelect);
}
//...................
return (IEnumerable<SelectListItem>)sRetVal;
}
或者只是为你做新的帮手。像这样:
public static IEnumerable<SelectListItem> SetSelected(this IEnumerable<SelectListItem> selectList, string selectedValue)
{
var newList = new List<SelectListItem>();
var oldList = selectList.ToList();
for (var i = 0; i < oldList.Count; i++)
{
var item = oldList[i];
item.Selected = string.Equals(item.Value, selectedValue, StringComparison.CurrentCultureIgnoreCase);
newList.Insert(i, item);
}
return newList;
}
以下是用法:
@Html.DropDownListFor(model => model.Country, CommonHelpers.CountrySelectList().SetSelected(model.Country), "---Select---")