Data Binding in ASP.NET MVC MultiSelect

28 Aug 202624 minutes to read

The MultiSelect loads data either from local data sources or remote data services using the dataSource property. It accepts data of type array or DataManager.

The MultiSelect also supports different kinds of data services such as OData, OData V4, and Web API, and data formats such as XML, JSON, and JSONP with the help of DataManager adaptors.

Field	Type	Description
text	string	Specifies the display text of each list item.
value	number or string	Specifies the hidden data value mapped to each list item; it should contain a unique value.
groupBy	string	Specifies the category under which the list item is grouped.
iconCss	string	Specifies the icon class of each list item.

When binding complex data to the MultiSelect, fields must be mapped correctly. Otherwise, the selected item is undefined.

Binding local data

Local data can be represented in one of the following ways.

1. Array of strings

The MultiSelect supports loading an array of primitive data such as strings and numbers. Here, both the value and text fields act the same.

CSHTML

@Html.EJS().MultiSelect("default").Placeholder("Select games").DataSource((IEnumerable<object>)ViewBag.data).Render()

Arrayofstrings.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 MultiSelectController : Controller
    {
        public ActionResult arrayofstrings()
        {
            ViewBag.data = new string[] { "Badminton", "Basketball", "Cricket", "Football", "Golf", "Gymnastics", "Hockey", "Tennis" };
            return View();
        }
    }
}

2. Array of objects

The MultiSelect can generate its list items from an array of complex data. For this, the appropriate columns must be mapped to the fields property.

In the following example, the Id and Game columns from the complex data are mapped to the value and text fields, respectively.

CSHTML

@Html.EJS().MultiSelect("default").Placeholder("Select games").DataSource((IEnumerable<object>)ViewBag.data).Mode(Syncfusion.EJ2.DropDowns.VisualMode.Box).Fields(new Syncfusion.EJ2.DropDowns.MultiSelectFieldSettings { Text = "Game", Value = "Id" }).Render()

GameList.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication1.Models
{
    public class GameList
    {
        public string Id { get; set; }
        public string Game { get; set; }

        public List<GameList> GameLists()
        {
            List<GameList> game = new List<GameList>();
            game.Add(new GameList { Id = "Game1", Game = "American Football" });
            game.Add(new GameList { Id = "Game2", Game = "Badminton" });
            game.Add(new GameList { Id = "Game3", Game = "Basketball" });
            game.Add(new GameList { Id = "Game3", Game = "Basketball" });
            game.Add(new GameList { Id = "Game4", Game = "Cricket" });
            game.Add(new GameList { Id = "Game5", Game = "Football" });
            game.Add(new GameList { Id = "Game6", Game = "Golf" });
            game.Add(new GameList { Id = "Game7", Game = "Hockey" });
            game.Add(new GameList { Id = "Game8", Game = "Rugby" });
            game.Add(new GameList { Id = "Game9", Game = "Snooker" });
            game.Add(new GameList { Id = "Game10", Game = "Tennis" });
            return game;
        }
    }
}

3. Array of complex objects

The MultiSelect can generate its list items from an array of complex data with nested objects. For this, the appropriate columns must be mapped to the fields property using dot notation.

In the following example, the Code.Id and Country.CountryId columns from the complex data are mapped to the value and text fields, respectively.

CSHTML

@Html.EJS().MultiSelect("games").Placeholder("Select a game").PopupHeight("200px").DataSource((IEnumerable<Object>)ViewBag.data).Fields(new Syncfusion.EJ2.DropDowns.MultiSelectFieldSettings { Text = "Country.CountryId", Value = "Code.Id" }).Render()

Complex.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication1.Models
{
    public class Code
    {
        public string Id { get; set; }
    }

    public class Country
    {
        public string CountryId { get; set; }
    }
    public class Complex
    {
        public Country Country { get; set; }
        public Code Code { get; set; }
        public List<Complex> GetData()
        {
            List<Complex> data = new List<Complex>();
            data.Add(new Complex() { Country = new Country() { CountryId = "Australia" }, Code = new Code() { Id = "AU" } });
            data.Add(new Complex() { Country = new Country() { CountryId = "Bermuda" }, Code = new Code() { Id = "BM" } });
            data.Add(new Complex() { Country = new Country() { CountryId = "Canada" }, Code = new Code() { Id = "CA" } });
            data.Add(new Complex() { Country = new Country() { CountryId = "Cameroon" }, Code = new Code() { Id = "CM" } });
            data.Add(new Complex() { Country = new Country() { CountryId = "Denmark" }, Code = new Code() { Id = "DK" } });
            data.Add(new Complex() { Country = new Country() { CountryId = "France" }, Code = new Code() { Id = "FR" } });
            return data;
        }
    }
}

Binding remote data

The MultiSelect supports retrieval of data from remote data services with the help of the DataManager control. The Query property is used to fetch data from the data source and bind it to the MultiSelect.

The following sample displays the first 6 contacts from the Customers table of the Northwind data service.

CSHTML

@Html.EJS().MultiSelect("customers").Placeholder("Select a customer").PopupHeight("200px").DataSource(dataManger =>
            dataManger.Url("https://services.odata.org/V4/Northwind/Northwind.svc/").Adaptor("ODataV4Adaptor").CrossDomain(true)).Fields(new Syncfusion.EJ2.DropDowns.MultiSelectFieldSettings
            {
                Text = "ContactName",
                Value = "CustomerID"
            }).Query("new ej.data.Query().from('Customers').select(['ContactName', 'CustomerID']).take(6)").Render()

Remotedata.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 MultiSelectController : Controller
    {
        public ActionResult remotedata()
        {
            return View();
        }
    }
}

Bind to URL adaptor

The MultiSelect supports retrieval of data through the UrlAdaptor.

CSHTML

@Html.EJS().MultiSelect("games").Placeholder("Select a Country").PopupHeight("200px").DataSource(dataManger =>
    dataManger.Url("/MultiSelect/UrlDatasource").Adaptor("UrlAdaptor").CrossDomain(true)).Fields(new Syncfusion.EJ2.DropDowns.MultiSelectFieldSettings
    {
        Value = "ShipCountry"
    }).Render()

Urldata.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 MultiselectController : Controller
    {
         public ActionResult Index()
        {
            return View();
        }
        public ActionResult UrlDatasource([FromBody]Data dm)
        {
            var val = OrdersDetails.GetAllRecords();
            var Data = val.ToList();
            var count = val.Count();
            if (dm.where != null)
            {
                Data = (from cust in Data
                        where cust.ShipCountry.ToLower().StartsWith(dm.@where[0].value.ToString())
                        select cust).ToList();
            }
            if (dm.take != 0)
                Data = Data.Take(dm.take).ToList();
            return Json(Data);
        }


        public class Data
        {
            public int take { get; set; }
            public List<Wheres> where { get; set; }
        }

        public class Wheres
        {
            public string field { get; set; }
            public bool ignoreAccent { get; set; }

            public bool ignoreCase { get; set; }

            public bool isComplex { get; set; }

            public string value { get; set; }
            public string Operator { get; set; }

        }
        public class OrdersDetails
        {
            public static List<OrdersDetails> order = new List<OrdersDetails>();
            public OrdersDetails()
            {

            }
            public OrdersDetails(int OrderID, string CustomerId, int EmployeeId, double Freight, bool Verified, DateTime OrderDate, string ShipCity, string ShipName, string ShipCountry, DateTime ShippedDate, string ShipAddress)
            {
                this.OrderID = OrderID;
                this.CustomerID = CustomerId;
                this.EmployeeID = EmployeeId;
                this.Freight = Freight;
                this.ShipCity = ShipCity;
                this.Verified = Verified;
                this.OrderDate = OrderDate;
                this.ShipName = ShipName;
                this.ShipCountry = ShipCountry;
                this.ShippedDate = ShippedDate;
                this.ShipAddress = ShipAddress;
            }
            public static List<OrdersDetails> GetAllRecords()
            {
                if (order.Count() == 0)
                {
                    int code = 10000;
                    for (int i = 1; i < 10; i++)
                    {
                        order.Add(new OrdersDetails(code + 1, "ALFKI", i + 0, 2.3 * i, false, new DateTime(1991, 05, 15), "Berlin", "Simons bistro", "Denmark", new DateTime(1996, 7, 16), "Kirchgasse 6"));
                        order.Add(new OrdersDetails(code + 2, "ANATR", i + 2, 3.3 * i, true, new DateTime(1990, 04, 04), "Madrid", "Queen Cozinha", "Brazil", new DateTime(1996, 9, 11), "Avda. Azteca 123"));
                        order.Add(new OrdersDetails(code + 3, "ANTON", i + 1, 4.3 * i, true, new DateTime(1957, 11, 30), "Cholchester", "Frankenversand", "Germany", new DateTime(1996, 10, 7), "Carrera 52 con Ave. Bolívar #65-98 Llano Largo"));
                        order.Add(new OrdersDetails(code + 4, "BLONP", i + 3, 5.3 * i, false, new DateTime(1930, 10, 22), "Marseille", "Ernst Handel", "Austria", new DateTime(1996, 12, 30), "Magazinweg 7"));
                        order.Add(new OrdersDetails(code + 5, "BOLID", i + 4, 6.3 * i, true, new DateTime(1953, 02, 18), "Tsawassen", "Hanari Carnes", "Switzerland", new DateTime(1997, 12, 3), "1029 - 12th Ave. S."));
                        code += 5;
                    }
                }
                return order;
            }

            public int? OrderID { get; set; }
            public string CustomerID { get; set; }
            public int? EmployeeID { get; set; }
            public double? Freight { get; set; }
            public string ShipCity { get; set; }
            public bool Verified { get; set; }
            public DateTime OrderDate { get; set; }

            public string ShipName { get; set; }

            public string ShipCountry { get; set; }

            public DateTime ShippedDate { get; set; }
            public string ShipAddress { get; set; }
        }
    }
}

Web API adaptor

Use the WebApiAdaptor to bind the MultiSelect to a Web API created using OData.

CSHTML

<div id='web-data' class='col-lg-6' style='padding-top:15px'>
    <div class='content'>
        @Html.EJS().MultiSelect("games").Placeholder("Select customer").DataSource(dataManger =>
            dataManger.Url("/api/MultiSelect/").Adaptor("WebApiAdaptor")).Render()
    </div>
</div>

Webapi.cs

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

namespace WebApplication1.Controllers
{
    [Route("api/[controller]")]
    public class MultiselectController : Controller
    {
        List<string> game = new List<string>();
        [HttpGet]
        public List<string> Get()
        {
            game.Add("Badminton");
            game.Add("Basketball");
            game.Add("Cricket");
            game.Add("Golf");
            game.Add("Gymnastics");
            game.Add("Tennis");
            game.Add("Hockey");
            return game;
        }
    }
}

Binding with OData services

OData is a standardized protocol for creating and consuming data. You can retrieve data from an OData service using the DataManager.

The following example shows remote data binding using an OData service.

CSHTML

<div id='o-data' class='col-lg-6' style='padding-top:15px'>
    <div class='content'>
        @Html.EJS().MultiSelect("customers").Placeholder("Select a customer").PopupHeight("200px").DataSource(dataManger =>
            dataManger.Url("https://js.syncfusion.com/ejServices/Wcf/Northwind.svc/Orders/").Adaptor("ODataAdaptor").CrossDomain(true)).Fields(new Syncfusion.EJ2.DropDowns.MultiSelectFieldSettings
            {
                Value = "CustomerID"
            }).Query("new ej.data.Query().select(['CustomerID']).take(7)").Render()
    </div>
</div>

Odata.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 MultiselectController : Controller
    {
        public ActionResult odata()
        {
            return View();
        }
    }
}

Offline mode

To avoid a postback for every action, set the MultiSelect to load all data on initialization and process actions on the client. To enable this behavior, use the Offline property of DataManager.

The following example shows remote data binding with offline mode enabled.

CSHTML

<div id='o-data' class='col-lg-6' style='padding-top:15px'>
    <div class='content'>
        @Html.EJS().MultiSelect("customers").Placeholder("Select a customer").PopupHeight("200px").DataSource(dataManger =>
            dataManger.Url("http://js.syncfusion.com/ejServices/Wcf/Northwind.svc/Orders/").Offline(true).Adaptor("ODataAdaptor").CrossDomain(true)).Fields(new Syncfusion.EJ2.DropDowns.MultiSelectFieldSettings
            {
                Value = "CustomerID"
            }).Query("new ej.data.Query().select(['CustomerID']).take(7)").Render()
    </div>
</div>

Offline.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 MultiselectController : Controller
    {
        public ActionResult offline()
        {
            return View();
        }
    }
}

See also

• How to load data using a template
• How to group the data using a header
• How to filter the bound data