remote validation in asp.net mvc

 in this article, I will show remote validation in asp.net mvc

model :

    public class User

    {

        public int Id { get; set; }

        [Remote("IsUserExists", "Home", ErrorMessage = "User name already exist")]

        [Required(ErrorMessage = "Please Enter User name.")]

        public string Username { get; set; }

    }

controller :

        List<User> objusers = new List<User>()

        {

            new User {Username="Ajay",Id=1},

            new User {Username="Sharavan",Id=2},

            new User {Username="Dhruv",Id=3},

        };

        public JsonResult IsUserExists(string Username)

        {

            return Json(!objusers.Any(x => x.Username.ToLower() == Username.ToLower()), JsonRequestBehavior.AllowGet);

        }

view :

@model RemoteValidation.Models.User

@using (Html.BeginForm())

{

    @Html.AntiForgeryToken()

    <div class="form-horizontal">

        <hr />

        @Html.ValidationSummary(true, "", new { @class = "text-danger" })

        <div class="form-group">

            @Html.LabelFor(model => model.Username, htmlAttributes: new { @class = "control-label col-md-2" })

            <div class="col-md-10">

                @Html.EditorFor(model => model.Username, new { htmlAttributes = new { @class = "form-control" } })

                @Html.ValidationMessageFor(model => model.Username, "", new { @class = "text-danger" })

            </div>

        </div>

        <div class="form-group">

            <div class="col-md-offset-2 col-md-10">

                <input type="submit" value="Create" class="btn btn-primary" />

            </div>

        </div>

    </div>

}

<script src="~/Scripts/jquery-3.3.1.min.js"></script>

<script src="~/Scripts/jquery.validate.min.js"></script>

<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>