无法System.Web.Mail名空间？

Question

我想做一个收发电子邮件的程序，其中要用到System.Web.Mail下的MailMessage类，可是运行的时候却提示在Web下无法找到Mail名空间？更奇怪的是，我用别人现成的代码，其中也有using System.Web.Mail;这一行，运行却没问题，这是怎么回事？

Answer 1

可能是你自己的没有把dll添加进来吧

Answer 2

请问一下怎么添加？为什么这个名空间需要添加dll？

Answer 3

using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Mail;
using System.Text;namespace mailDaemon
{
    class MailSender
    {
        private const string SERVER_IP = "61.181.255.80";
        private const string SENDER_EMAIL = "[email protected]";
        private const string USERNAME = "mailist";
        private const string PASSWORD = "bu2kwh1at";
        private const string SUBJECT = "高速路商机速递";
        string _server;
        string _senderEmail;
        string _username;
        string _password;
        static bool mailSent = false;        public MailSender(string server, string senderEmail, string username, string password)
        {
            _server = server;
            _senderEmail = senderEmail;
            _username = username;
            _password = password;
        }
        public MailSender():this(SERVER_IP, SENDER_EMAIL, USERNAME, PASSWORD)
        {
            
        }
        public void SendMail(string email, string content)
        {
            MailMessage msg = new MailMessage(_senderEmail, email, SUBJECT, content);
            msg.BodyEncoding = Encoding.UTF8;
            msg.Priority = MailPriority.High;
            msg.IsBodyHtml = true;
            SmtpClient client = new SmtpClient(_server);
            NetworkCredential credential = new NetworkCredential(_username, _password);
            client.UseDefaultCredentials = false;
            client.Credentials = credential;
            client.SendCompleted += new SendCompletedEventHandler(client_SendCompleted);
            client.SendAsync(msg, "Message Sent.");
            Console.WriteLine(email + "邮件发送中，按C取消发送");
            //string answer = Console.ReadLine();
            //if (answer.StartsWith("c") && mailSent == false)
            //{
            //    client.SendAsyncCancel();
            //}
            Console.WriteLine(email + "处理完成");
        }        void client_SendCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
        {
            String token = (string)e.UserState;            if (e.Cancelled)
            {
                Console.WriteLine("[{0}] Send canceled.", token);
            }
            if (e.Error != null)
            {
                Console.WriteLine("[{0}] {1}", token, e.Error.ToString());
            }
            else
            {
                Console.WriteLine("Message sent.");
            }
            mailSent = true;
        }
    }
}
参考,参考!