我对如何在 Razor View 中实现地址的级联下拉列表感兴趣。我的站点实体有一个 SuburbId 属性。 Suburb 有一个 CityId,City 有 ProvinceId。我想在站点 View 上显示所有郊区、城市和省的下拉菜单,例如郊区下拉列表最初将显示“首先选择一个城市”,城市下拉列表将显示“首先选择一个省份”。选择省份时,该省份的城市人口等。
我怎样才能实现这个目标?我从哪里开始?
最佳答案
我们用一个例子来说明一下。一如既往地从模型开始:
public class MyViewModel
{
public string SelectedProvinceId { get; set; }
public string SelectedCityId { get; set; }
public string SelectedSuburbId { get; set; }
public IEnumerable<Province> Provinces { get; set; }
}
public class Province
{
public string Id { get; set; }
public string Name { get; set; }
}
接下来是 Controller :
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new MyViewModel
{
// TODO: Fetch those from your repository
Provinces = Enumerable.Range(1, 10).Select(x => new Province
{
Id = (x + 1).ToString(),
Name = "Province " + x
})
};
return View(model);
}
public ActionResult Suburbs(int cityId)
{
// TODO: Fetch the suburbs from your repository based on the cityId
var suburbs = Enumerable.Range(1, 5).Select(x => new
{
Id = x,
Name = "suburb " + x
});
return Json(suburbs, JsonRequestBehavior.AllowGet);
}
public ActionResult Cities(int provinceId)
{
// TODO: Fetch the cities from your repository based on the provinceId
var cities = Enumerable.Range(1, 5).Select(x => new
{
Id = x,
Name = "city " + x
});
return Json(cities, JsonRequestBehavior.AllowGet);
}
}
最后是一个 View :
@model SomeNs.Models.MyViewModel
@{
ViewBag.Title = "Home Page";
}
<script type="text/javascript" src="/scripts/jquery-1.4.4.js"></script>
<script type="text/javascript">
$(function () {
$('#SelectedProvinceId').change(function () {
var selectedProvinceId = $(this).val();
$.getJSON('@Url.Action("Cities")', { provinceId: selectedProvinceId }, function (cities) {
var citiesSelect = $('#SelectedCityId');
citiesSelect.empty();
$.each(cities, function (index, city) {
citiesSelect.append(
$('<option/>')
.attr('value', city.Id)
.text(city.Name)
);
});
});
});
$('#SelectedCityId').change(function () {
var selectedCityId = $(this).val();
$.getJSON('@Url.Action("Suburbs")', { cityId: selectedCityId }, function (suburbs) {
var suburbsSelect = $('#SelectedSuburbId');
suburbsSelect.empty();
$.each(suburbs, function (index, suburb) {
suburbsSelect.append(
$('<option/>')
.attr('value', suburb.Id)
.text(suburb.Name)
);
});
});
});
});
</script>
<div>
Province:
@Html.DropDownListFor(x => x.SelectedProvinceId, new SelectList(Model.Provinces, "Id", "Name"))
</div>
<div>
City:
@Html.DropDownListFor(x => x.SelectedCityId, Enumerable.Empty<SelectListItem>())
</div>
<div>
Suburb:
@Html.DropDownListFor(x => x.SelectedSuburbId, Enumerable.Empty<SelectListItem>())
</div>
作为一项改进,可以通过编写 jquery 插件来缩短 javascript 代码,以避免重复某些部分。
<小时/>更新:
谈论插件时,您可能会想到以下内容:
(function ($) {
$.fn.cascade = function (options) {
var defaults = { };
var opts = $.extend(defaults, options);
return this.each(function () {
$(this).change(function () {
var selectedValue = $(this).val();
var params = { };
params[opts.paramName] = selectedValue;
$.getJSON(opts.url, params, function (items) {
opts.childSelect.empty();
$.each(items, function (index, item) {
opts.childSelect.append(
$('<option/>')
.attr('value', item.Id)
.text(item.Name)
);
});
});
});
});
};
})(jQuery);
然后简单地将其连接起来:
$(function () {
$('#SelectedProvinceId').cascade({
url: '@Url.Action("Cities")',
paramName: 'provinceId',
childSelect: $('#SelectedCityId')
});
$('#SelectedCityId').cascade({
url: '@Url.Action("Suburbs")',
paramName: 'cityId',
childSelect: $('#SelectedSuburbId')
});
});
关于asp.net-mvc - MVC 3 Razor View 中的级联下拉菜单,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4458970/