Captcha Mvc

Install-Package CaptchaMvc.Mvc5

using System.Web.Mvc;

using CaptchaMvc.HtmlHelpers;

namespace MvcCaptcha.Controllers

{

    public class HomeController : Controller

    {

        public ActionResult Index() { return View(); }

        public ActionResult Captcha() { return View(); }

        [CaptchaMvc.Attributes.CaptchaVerify("Captcha is not valid")]

        [HttpPost]

        public ActionResult Captcha(string empty)

        {

            if (ModelState.IsValid)

            {

                ViewBag.ErrMessage = "Message: captcha is valid.";

                return View();

            }

            ViewBag.ErrMessage = "Error: captcha is not valid.";

            return View();

        }

        public ActionResult MathCaptcha() { return View(); }

        [HttpPost]

        public ActionResult MathCaptcha(string empty)

        {

            if (this.IsCaptchaValid("Captcha is not valid"))

            {

                ViewBag.ErrMessage = "Message: captcha is valid.";

                return View();

            }

            ViewBag.ErrMessage = "Error: captcha is not valid.";

            return View();

        }

    }

}

@using CaptchaMvc.HtmlHelpers

@model MvcCaptcha.Models.Feedback 

@{ ViewBag.Title = "Word Captcha"; }

<style>.Error{color: red}.input-validation-error{border: 1px solid #ff0000;background-color: #ffeeee;}</style>

<h2>Word Captcha</h2>

@using (Html.BeginForm())

{

    @Html.ValidationSummary(true)

    <fieldset>

        <legend>Feedback</legend>

        <div class="editor-label">

            @Html.LabelFor(model => model.Title)

        </div>

        <div class="editor-field">

            @Html.TextBoxFor(model => model.Title, new { @class = "form-control" })

            @Html.ValidationMessageFor(model => model.Title)

        </div>

        <div class="editor-label">

            @Html.LabelFor(model => model.Comment)

        </div>

        <div class="editor-field">

            @Html.TextAreaFor(model => model.Comment, 3, 20, new{@class="form-control"})

            @Html.ValidationMessageFor(model => model.Comment)

        </div>

        @*@Html.MathCaptcha()*@

        @Html.Captcha(3)

        <br />

        <p class="Error">  @ViewBag.ErrMessage </p>

        <p> <input type="submit" value="Send" /> </p>

    </fieldset>

}