How to count remote data bound to ASP.NET MVC DropDownList

17 Aug 20262 minutes to read

Before control rendering, you can get the total items count by using actionComplete event with its result arguments. After rendering this control, you can get the total items count by using getItems method.

CSHTML

@Html.EJS().Button("btn").Content("Get Items").Render()
@Html.EJS().DropDownList("customers").Placeholder("Select a customer").PopupHeight("200px").DataSource(dataManger =>
            dataManger.Url("http://services.odata.org/V4/Northwind/Northwind.svc/").Adaptor("ODataV4Adaptor").CrossDomain(true)).Fields(new DropDownListFieldSettings
            {
                Text = "ContactName",
                Value = "CustomerID"
            }).Query((string)ViewBag.query).Render()
<script>
 function actionComplete (e) {
         // get total items count
         console.log("Total items count: " + e.result.length);
         var element = document.createElement('p');
         element.innerText = "Total items count: " + e.result.length;
         document.getElementById('event').append(element);
    }
    document.getElementById('btn').onclick = () => {
        var Obj = document.getElementById("customers").ej2_instances[0];
        // get items count using getItems method
        console.log("Total items count: " + Obj.getItems().length);
        let element = document.createElement('p');
        element.innerText = "Total items count: " + Obj.getItems().length;
        document.getElementById('event').append(element);
    };
</script>

Totalcount.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using WebApplication1.Models;

namespace WebApplication1.Controllers
{
    public class DropDownListController : Controller
    {
        public ActionResult totalcount()
        {
            return View();
        }
    }
}