C# 附件上传及发送电子邮件实例源代码

具体的上传页面实现，请见下文：

看到上传页面，控件很少：1个FileUpload、4个TextBox和1个Button。通过VS的界面设计器直接拖放出来。还有隐藏的3个验证控件：2个Request和1个邮件格式验证。

按钮OnClick事件代码：

 protected void btnUpload_Click(object sender, EventArgs e)
        {           
            string mess = "Nickname: "+txtNickname.Text + "<br />Link: " + txtLink.Text+"<br />Comments: "+txtComments.Text;
            try
            {
                SendMail("[e-mail]", "[e-mail]", fuFile.FileName + " uploaded", mess, txtEmail.Text, true, fuFile.FileName, fuFile.FileBytes, "smtphost", "username", "password");
                Response.Redirect("upload_thankyou.html",true);
            }
            catch(Exception ex)
            {
                lblMsg.Text = ex.Message;
            }
        }

通过fuFile.FileBytes得到客户端上传的文件内容，并调用SendMail函数发送附件到指定的邮箱。SendMail代码如下：

  public static void SendMail(string from, string to, string subject, string message, string replyto, bool hasatt, string filename, byte[] att, string host, string username, string password)
        {
            MailMessage em = new MailMessage(from, to);
            em.Subject = subject;
            em.Body = message;
            em.IsBodyHtml = true;
            if (replyto.Length > 0) em.ReplyTo = new MailAddress(replyto);
            if (hasatt)
            {
                Stream s = (Stream)(new MemoryStream(att));
                em.Attachments.Add(new Attachment(s, filename));
            }
            SmtpClient sc = new SmtpClient(host);
            sc.DeliveryMethod = SmtpDeliveryMethod.Network;
            System.Net.NetworkCredential oCredential = new System.Net.NetworkCredential(username, password);
            sc.UseDefaultCredentials = false;
            sc.Credentials = oCredential;
            sc.Send(em);
        }

发送完毕跳到Thankyou页面，大约三五分钟后指定的邮箱就收到附件了。

来源：http://siguchuan.blog.163.com/blog/static/953551872010101132353328/