@using Microsoft.Web.Helpers;
@ReCaptcha.GetHtml("<你的公钥>", "<你的私钥>")

@model IEnumerable<MvcApplication.Models.BookComment>
@{
    ViewBag.Title = "Index";
}
<h2>
    Index</h2>
<p>
    @Ajax.ActionLink("Create New", "Create", new
{
    BookId = ViewBag.BookId
},
new AjaxOptions { UpdateTargetId = "AddComment" })
</p>
<div id="AddComment">
</div>
<script type="text/javascript" src=
"http://www.google.com/recaptcha/api/js/recaptcha_ajax.js">
</script>
<script type="text/javascript">
    function DisplayCaptcha() {
        Recaptcha.destroy();
        Recaptcha.create("6Le27coSAAAAAK8KqpUIGvz3qTDXGa9ud9Xst4yY", "captcha", {});//你的公钥

    }
</script>
<table>
    <tr>
        <th>
            Comment
        </th>
        <th>
            Created
        </th>
    </tr>
    @foreach (var item in Model)
    {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.Comment)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Created)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Book.Title)
            </td>
        </tr>
    }
</table>

@model MvcApplication.Models.BookComment
@{
    ViewBag.Title = "Create";
}
<h2>
    Create</h2>
@section JavascriptAndCSS {
    <script src="@Url.Content("~/Scripts/jquery.validate.min.js")"
type="text/javascript"></script>
    <script src="
@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")"
type="text/javascript"></script>
}
<script type="text/javascript">
    function ReloadComments() {
        var reload = "@ViewBag.RefreshComments";
        if (reload == "False") {
            DisplayCaptcha();
        } else {
            $("#Comments").load("/BookComments/Index?BookId=@ViewBag.BookId");
        }
    }
</script>
@using (Ajax.BeginForm(new AjaxOptions
{
    UpdateTargetId = "AddComment",
    OnComplete = "ReloadComments"
}))
{
    @Html.Hidden("BookId", (int)ViewBag.BookId);
    @Html.ValidationSummary(true)
    <fieldset>
        <legend>BookComment</legend>
        <div class="editor-label">
            @Html.LabelFor(model => model.Comment)
        </div>
        <div class="editor-field">
            @Html.TextAreaFor(model => model.Comment)
            @Html.ValidationMessageFor(model => model.Comment)
        </div>
        <div class="editor-label">
            Are you human?
        </div>
        <div class="editor-field">
            <div id="captcha">
            </div>
            @Html.ValidationMessage("Captcha")
        </div>
        <p>
            <input type="submit" value="Create" />
        </p>
    </fieldset>
}

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using MvcApplication.Models;
using Microsoft.Web.Helpers;
using MvcApplication.Models;
namespace MvcApplication.Controllers
{
    public class BookCommentsController : Controller
    {
        private BookDBContext db = new BookDBContext();
        //
        // GET: /BookComments/
        public ActionResult Index(int BookId)
        {
            ViewBag.BookId = BookId;
            var bookcomments = db.BookComments.Include(
            b => b.Book).Where(b => b.BookId == BookId);
            return PartialView(bookcomments.ToList());
        }
        //
        // GET: /BookComments/Create
        public ActionResult Create(int BookId)
        {
            ViewBag.BookId = BookId;
            ViewBag.RefreshComments = false;
            return PartialView();
        }
        //
        // POST: /BookComments/Create
        [HttpPost]
        public ActionResult Create(BookComment bookcomment)
        {
            ViewBag.RefreshComments = false;
            var captchaSuccess = ReCaptcha.Validate(
            "6Le27coSAAAAAM6kZnXU8m1j9");//你的私钥

            if (ModelState.IsValid && captchaSuccess)
            {
                bookcomment.Created = DateTime.Now;
                db.BookComments.Add(bookcomment);
                db.SaveChanges();
                ViewBag.RefreshComments = true;
            }
            // if captcha failed add error message
            if (!captchaSuccess)
            {
                ModelState.AddModelError("Captcha",
                "Invalid CAPTCHA");
            }
            ViewBag.BookId = bookcomment.BookId;
            return PartialView(bookcomment);
        }
        protected override void Dispose(bool disposing)
        {
            db.Dispose();
            base.Dispose(disposing);
        }
    }
}

using System;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Data;  
using System.Drawing;  
using System.Text;  
using System.Windows.Forms;  
using System.Net;  
using System.Net.Mail;  
using System.Net.Mime;  
using System.IO;  
  
namespace SendMailExample  
{  
    /// <summary>  
    /// 作者：Andrew  
    /// Blog: http://blog.csdn.net/Andrew_wx  
    /// </summary>
    public partial class FormSendMail : Form  
    {  
        public FormSendMail()  
        {  
            InitializeComponent();  
        }  
  
        private void FormSendMail_Load(object sender, EventArgs e)  
        {  
            txtSmtpServer.Text = "smtp.qq.com";  
            txtSend.Text = "heuandmei@qq.com";  
            txtDisplayName.Text = "Andrew(王旭)";  
            txtPassword.Text = "";//密码  
            txtReceive.Text = "heuandmei@qq.com";  
            txtTitle.Text = "发信测试";  
            txtBody.Text = "This is a test(测试)";  
            rbtnNoSSL.Checked = true;  
        }  
  
        private void btnAddFiles_Click(object sender, EventArgs e)  
        {  
            OpenFileDialog odlg = new OpenFileDialog();  
            odlg.CheckFileExists = true;  
            //只接收有效的文件名  
            odlg.ValidateNames = true;  
            //允许一次选择多个文件作为附件  
            odlg.Multiselect = true;  
            if (odlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)  
            {  
                lstFiles.Items.AddRange(odlg.FileNames);  
            }  
              
        }  
  
        private void btnSend_Click(object sender, EventArgs e)  
        {  
            this.Cursor = Cursors.WaitCursor;  
            MailMessage mail = new MailMessage();  
            mail.From = new MailAddress(  
                txtSend.Text, txtDisplayName.Text, Encoding.UTF8);  
            mail.To.Add(txtReceive.Text);  
            mail.Subject = txtTitle.Text;  
            mail.SubjectEncoding = Encoding.Default;  
            mail.Body = txtBody.Text;  
            mail.BodyEncoding = Encoding.Default;  
            mail.IsBodyHtml = false;  
            mail.Priority = MailPriority.Normal;  
            //添加附件  
            Attachment attachment = null;  
            if (lstFiles.Items.Count > 0)  
            {  
                for (int i = 0; i < lstFiles.Items.Count; i++)  
                {  
                    string pathFileName = lstFiles.Items[i].ToString();  
                    string extName = Path.GetExtension(pathFileName).ToLower();  
                    //判断附件类型  
                    if (extName == ".rar" || extName == ".zip")  
                    {  
                        attachment = new Attachment(pathFileName, MediaTypeNames.Application.Zip);  
                    }  
                    else  
                    {  
                        attachment = new Attachment(pathFileName, MediaTypeNames.Application.Octet);  
                    }  
                    ContentDisposition cd = attachment.ContentDisposition;  
                    cd.CreationDate = File.GetCreationTime(pathFileName);  
                    cd.ModificationDate = File.GetLastWriteTime(pathFileName);  
                    cd.ReadDate = File.GetLastAccessTime(pathFileName);  
                    mail.Attachments.Add(attachment);  
  
                }  
            }  
            SmtpClient client = new SmtpClient();  
            client.Host = txtSmtpServer.Text;  
            client.Port = 25;  
            //是否使用安全套接字层加密连接  
            client.EnableSsl = rbtnUseSSL.Checked;  
            //不使用默认凭证，注意此句必须放在 client.Credentials 的上面  
            client.UseDefaultCredentials = false;  
            client.Credentials = new NetworkCredential(txtSend.Text, txtPassword.Text);  
            //邮件通过网络直接发送到服务器  
            client.DeliveryMethod = SmtpDeliveryMethod.Network;  
            try  
            {  
                client.Send(mail);  
                MessageBox.Show("发送成功");  
            }  
            catch (SmtpException ex)  
            {  
                MessageBox.Show("发送失败：" + ex.Message);  
            }  
            catch (Exception ex)  
            {  
                MessageBox.Show("发送失败：" + ex.Message);  
            }  
            finally  
            {  
                mail.Dispose();  
                client = null;  
                this.Cursor = Cursors.Default;  
            }  
        }  
    }  
}