on select change event - Html.DropDownListFor
Use the following code. It is used in my project. For Zone and Region I used two drop-down list. On change Zone data I loaded the Region drop-down.
In View page
@Html.DropDownList("ddlZone", new SelectList(@ViewBag.Zone, "Zone_Code", "Zone_Name"), "--Select--", new { @class = "LoginDropDown" })
@Html.DropDownList("ddlRegion", Enumerable.Empty<SelectListItem>(), new { @class = "LoginDropDown" })
The Zone need to load when the view page is load.
In the controller write this method for Region Load
[WebMethod]
public JsonResult LoadRegion(string zoneCode)
{
ArrayList arl = new ArrayList();
RASolarERPData objDal = new RASolarERPData();
List<tbl_Region> region = new List<tbl_Region>();
region = erpDal.RegionByZoneCode(zoneCode);
foreach (tbl_Region rg in region)
{
arl.Add(new { Value = rg.Reg_Code.ToString(), Display = rg.Reg_Name });
}
return new JsonResult { Data = arl };
}
Then use the following JavaScript
<script type="text/javascript">
$(document).ready(function () {
$('#ddlZone').change(function () {
LoadRegion(this.value);
});
function LoadRegion(zoneCode) {
$.ajax({
type: "POST",
url: '@Url.Action("LoadRegion", "RSFSecurity")',
data: "{'zoneCode':'" + zoneCode + "'}",
contentType: "application/json; charset=utf-8",
dataType: 'json',
cache: false,
success: function (data) {
$('#ddlRegion').get(0).options.length = 0;
$('#ddlRegion').get(0).options[0] = new Option("--Select--", "0");
$.map(data, function (item) {
$('#ddlRegion').get(0).options[$('#ddlRegion').get(0).options.length] = new Option(item.Display, item.Value);
});
},
error: function () {
alert("Failed to load Item");
}
});
}
});
</script>
Give both dropdowns unique IDs using the HTTPAttributes field:
@Html.DropDownListFor(m => m.DistrictId, ViewData["DMManagers"] as IEnumerable<SelectListItem>, "Select One", new {@id="ddlDMManagers"})
2nd dropdown should be initialized as an empty list:
@Html.DropDownListFor(m => m.TMId, Enumerable.Empty<SelectListItem>(), new {@id="ddlTMManagers"})
If you don't mind using jQuery ajax to update the 2nd dropdown when a 'change' event is triggered on the 1st dropdown:
$(function() {
$('select#ddlDMManagers').change(function() {
var districtId = $(this).val();
$.ajax({
url: 'LoadTerritoryManagers',
type: 'POST',
data: JSON.stringify({ districtId: districtId }),
dataType: 'json',
contentType: 'application/json',
success: function (data) {
$.each(data, function (key, TMManagers) {
$('select#ddlTMManagers').append('<option value="0">Select One</option>');
// loop through the TM Managers and fill the dropdown
$.each(TMManagers, function(index, manager) {
$('select#ddlTMManagers').append(
'<option value="' + manager.Id + '">'
+ manager.Name +
'</option>');
});
});
}
});
});
});
Add this class to your controller namespace:
public class TMManager
{
public int Id {get; set;}
public string Name {get; set;}
}
You will need to update your controller action, LoadTerritoryManagers(), to respond to the ajax request and return a JSON array of {Id,Name} objects.
[HttpPost]
public ActionResult LoadTerritoryManagers(int districtId)
{
var _TMS = (from c in SessionHandler.CurrentContext.ChannelGroups
join cgt in SessionHandler.CurrentContext.ChannelGroupTypes on c.ChannelGroupTypeId equals cgt.ChannelGroupTypeId
where cgt.Name == "Territory" && c.ParentChannelGroupId == districtId
select new TMManager(){ Id = c.ChannelGroupId, Name = c.Name }).OrderBy(m => m.Name);
if (_TMS == null)
return Json(null);
List<TMManager> managers = (List<TMManager>)_TMS.ToList();
return Json(managers);
}
We can use the jquery to get and fill the dropdown like this:
<script>
function FillCity() {
var stateId = $('#State').val();
$.ajax({
url: '/Employees/FillCity',
type: "GET",
dataType: "JSON",
data: { State: stateId},
success: function (cities) {
$("#City").html(""); // clear before appending new list
$.each(cities, function (i, city) {
$("#City").append(
$('<option></option>').val(city.CityId).html(city.CityName));
});
}
});
}
</script>
For more detail see MVC DropDownListFor fill on selection change of another dropdown