@using Mvc.CascadeDropDown
//First simple dropdown
@Html.DropDownListFor(m=>m.SelectedCountry, Model.Countries,
"Please select a Country", new {@class="form-control"})
//Dropdown list for SelectedCity property that depends on selection of SelectedCountry property
@Html.CascadingDropDownListFor(
expression: m => m.SelectedCity,
triggeredByProperty: m => m.SelectedCountry, //Parent property that trigers dropdown data loading
url: Url.Action("GetCities", "Home"), //Url of action that returns dropdown data
ajaxActionParamName: "country", //Parameter name for the selected parent value that url action receives
optionLabel: "Please select a City", // Option label
disabledWhenParrentNotSelected: true, //If true, disables dropdown until parrent dropdown selected
htmlAttributes: new { @class = "form-control" }) //Html attributes
//Dropdown list for SelectedStreet property that depends on selection of SelectedCity property
@Html.CascadingDropDownListFor(m => m.SelectedStreet, m => m.SelectedCity,
Url.Action("GetStreets", "Home"), "city", "Please select a Street", true, new { @class = "form-control" })