As always you start with a model:
public class MyViewModel
{
public int? Year { get; set; }
public int? Month { get; set; }
public IEnumerable<SelectListItem> Years
{
get
{
return Enumerable.Range(2000, 12).Select(x => new SelectListItem
{
Value = x.ToString(),
Text = x.ToString()
});
}
}
}
then a controller:
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new MyViewModel();
return View(model);
}
public ActionResult Months(int year)
{
if (year == 2011)
{
return Json(
Enumerable.Range(1, 3).Select(x => new { value = x, text = x }),
JsonRequestBehavior.AllowGet
);
}
return Json(
Enumerable.Range(1, 12).Select(x => new { value = x, text = x }),
JsonRequestBehavior.AllowGet
);
}
}
and finally a view:
@model AppName.Models.MyViewModel
@Html.DropDownListFor(
x => x.Year,
new SelectList(Model.Years, "Value", "Text"),
"-- select year --"
)
@Html.DropDownListFor(
x => x.Month,
Enumerable.Empty<SelectListItem>(),
"-- select month --"
)
<script type="text/javascript">
$('#Year').change(function () {
var selectedYear = $(this).val();
if (selectedYear != null && selectedYear != '') {
$.getJSON('@Url.Action("Months")', { year: selectedYear }, function (months) {
var monthsSelect = $('#Month');
monthsSelect.empty();
$.each(months, function (index, month) {
monthsSelect.append($('<option/>', {
value: month.value,
text: month.text
}));
});
});
}
});
</script>
Obviously you will notice that in my example I have hardcoded all the values. You should improve this logic by using notions like current year, current month, probably even fetch those values from a repository, etc... but for the purpose of the demonstration this should be enough to put you on the right track.
