将换行符附加到电子邮件

Question

所以我编写了一个简单的 C# WinForms 应用程序，它只有一个按钮控件，我将在每个月的 25 日单击它来通知我的用户支付他们的域订阅费用。我会把它做成一个windows服务，以便以后有时间时它可以自动运行。

我在这个 SO 帖子中从 @Tartori 那里得到了我的实现：Sending emails from a windows forms application，它按照我想要的方式工作。

一切都很好，但现在的问题是，当我将测试邮件发送到一个电子邮件地址时，我在 Outlook 上设置了相同的帐户，但现在当我通过网络使用 Gmail 查看相同的测试邮件时根据以下两个屏幕截图，不附加换行符：

请告诉我如何克服这个问题。我的代码如下：

        private void btnSendMail_Click(object sender, EventArgs e)
        {
            MailAddress from = new MailAddress("user@domain.co.za", "Name Surname");

            List<MailAddress> cc = new List<MailAddress>();
            cc.Add(new MailAddress("user2@domain.co.za", "Name2 Surname2"));
            string subjectText = "Friendly Domain Payment Reminder: " + DateTime.Now.ToShortDateString();
            SendEmail(subjectText, from, cc);
        }



        protected void SendEmail(string _subject, MailAddress _from, List<MailAddress> _cc, List<MailAddress> _bcc = null)
        {
            string Text = "";
            SmtpClient mailClient = new SmtpClient("mail.backlinkdesigns.co.za");
            MailMessage msgMail;
            Text = "Good day" + "</br>" + "</br>" + "I hope this message finds you well."                 msgMail = new MailMessage();
            msgMail.From = _from;
            MailAddress outlook= new MailAddress("user@domain.co.za", "User Surbname");
            MailAddress gmailAccount = new MailAddress("user@gmail.com", "Name Surname");
            msgMail.To.Add(outlook);
            msgMail.To.Add(gmailAccount );

            foreach (MailAddress addr in _cc)
            {
                msgMail.CC.Add(addr);
            }
            if (_bcc != null)
            {
                foreach (MailAddress addr in _bcc)
                {
                    msgMail.Bcc.Add(addr);
                }
            }
            msgMail.Subject = _subject;
            msgMail.Body = Text;
            msgMail.IsBodyHtml = true;
            mailClient.Send(msgMail);
            msgMail.Dispose();

            List<MailAddress> countVar = new List<MailAddress>();
            countVar.Add(outlook);
            countVar.Add(gmailAccount );
            var temp = countVar.Count;
            MessageBox.Show("Your email has been successfully sent to " + temp + " users show below: " + "\n\n" + outlook+ "\n" + gmailAccount + "\n" + "\n\n" + "From: " + _from, "Message Status", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
        }

更新： 下面附上 HTML Visualizer，当我使用 </br> 来证明我在代码中得到换行符时。它们在 Outlook 应用程序中显示良好，但在网络上却没有。请在发布解决方案之前尝试复制粘贴代码示例，因为 Environment.NewLine 不能解决问题。

Answer 1

这适用于我的 Gmail 和 Outlook。

  public void SendMail()
    {            

        SmtpClient smtpClient = new SmtpClient(<CLIENT>);
        MailMessage message = new MailMessage(<FROM>, <TO>);

        message.Subject = "Test";
        message.IsBodyHtml = true;

        string html = "<p>hey</p><p></p><p>hey 2</p><p>hey 3</p>";
        AlternateView htmlView = AlternateView.CreateAlternateViewFromString(html, new ContentType("text/html"));

        message.AlternateViews.Add(htmlView);

        smtpClient.Send(message);
    }

Gmail：

展望：

[更新]

对于你的特殊代码试试这个：

protected void SendEmail(string _subject, MailAddress _from, List<MailAddress> _cc, List<MailAddress> _bcc = null)
    {

        SmtpClient mailClient = new SmtpClient("mail.backlinkdesigns.co.za");
        MailMessage msgMail = new MailMessage(); 
        mailClient.UseDefaultCredentials = false;
        mailClient.Credentials = new NetworkCredential("user@domain.co.za", "password");
        var Text = "Good day" + "<br><br/>" + "I hope this message finds you well.";                

        msgMail.From = _from;
        var mailCollection = new MailAddressCollection()
        {
            new MailAddress("user@domain.co.za", "User Surbname"),
            new MailAddress("user@gmail.com", "Name Surname")
        };

        foreach (var mailAddress in mailCollection)
        {
            msgMail.To.Add(mailAddress);
        }

        foreach (MailAddress addr in _cc)
        {
            msgMail.CC.Add(addr);
        }
        if (_bcc != null)
        {
            foreach (MailAddress addr in _bcc)
            {
                msgMail.Bcc.Add(addr);
            }
        }
        msgMail.Subject = _subject;
        msgMail.IsBodyHtml = true;

        AlternateView htmlView = AlternateView.CreateAlternateViewFromString(Text, new ContentType("text/html"));
        msgMail.AlternateViews.Add(htmlView);

        mailClient.Send(msgMail);
        msgMail.Dispose();


        MessageBox.Show("Your email has been successfully sent to " + mailCollection.Count + " users show below: " + "\n\n" + mailCollection[0].User + "\n" + mailCollection[1].User + "\n" + "\n\n" + "From: " + _from, "Message Status", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
    }

Answer 2

@Harold_Finch 您可以只使用Environment.NewLine 属性而不是br>。这将插入为当前环境定义的换行符字符串。

Answer 3

你可以使用StringBuilder类。

StringBuilder sb = new StringBuilder();

sb.AppendLine("Your tex");

或

sb.AppendFormat("your text \n");

它会起作用的:)