ASP.NET发送邮件

在ASP.NET中实现发送邮件的功能，包括发送附近、HTML页面、图片，并且可以有多个发送对象。

在实际使用中用到队列、线程的技术，目的是防止发送邮件的过程阻碍主网站程序的运行。

具体代码如下：

public bool SendEmail(out string message)
        {
            string str3;
            bool flag = false;
            message = string.Empty;
            this.MailMM.Priority = MailPriority.Normal;
            this.MailMM.BodyEncoding = Encoding.UTF8;
            this.MailMM.IsBodyHtml = this.IsBodyHtml;
 
 
 
　　
            
            //关于图片
            AlternateView htmlView = null;
            try
            {
                htmlView = AlternateView.CreateAlternateViewFromString(StrMailContent,null, "text/html");
                

                for (int i = 0; i < aboImgSrcList.Count; i++)
                {
                    try
                    {
                        LinkedResource logo = new LinkedResource(aboImgSrcList[i], "image/jpeg");
                        logo.ContentId = "imgSrc" + (i + 1);

                        htmlView.LinkedResources.Add(logo);
                    }
                    catch (Exception EX)
                    {
                    }
                }

                MailMM.AlternateViews.Add(htmlView);
                //关于附件　　　　　　　　　　                
                for (int i = 0; i < this.AttachmentsList.Count; i++)
                {
                    string tempStr = this.AttachmentsList[i].ToString();
                    Attachment attach = new Attachment(tempStr);
                    this.MailMM.Attachments.Add(attach);
                }
            }
            catch (Exception)
            {
                
            }

            int count = 0;
            foreach (string str in this.arrMailTo.Keys)
            {
                try
                {
this.MailMM.To.Add(new MailAddress(this.arrMailTo[str]));
                    if (this.StrMailTitle != "")
                    {
                        this.MailMM.Subject = this.StrMailTitle;
                    }

                    this.MailMM.SubjectEncoding = Encoding.UTF8;
                    if (this.MailMM.From == null)
                    {
                        this.MailMM.From = new MailAddress(this.StrSender, (this.StrSenderDesc == "") ? this.StrSender : this.StrSenderDesc, Encoding.UTF8);
                    }

                    SmtpClient client = new SmtpClient
                    {
                        DeliveryMethod = SmtpDeliveryMethod.Network,
                        EnableSsl = false,
                        Host = this.MailServer,
                        Port = int.Parse(this.SmtpPort),
                        Credentials = new NetworkCredential(this.StrSenderUser, this.StrSenderUserPass)
                    };
                    client.Send(this.MailMM);
                    MailMM.To.Clear();
                    flag = true;
                    count++;

                }
                catch (SmtpException exception)
                {
                    flag = false;
                    message +="("+count+") "+DateTime.Now.ToString()+"  "+ this.arrMailTo[str] + ": " + exception.Message + ";
";
                }
                catch (InvalidCastException exc)
                {
                    flag = false;
                    message += "(" + count + ") " + DateTime.Now.ToString() + "  " + this.arrMailTo[str] + ": " + exc.Message + ";
";
                }
                catch (Exception ex)
                {
                    flag = false;
                    message += "(" + count + ") " + DateTime.Now.ToString() + "  " + this.arrMailTo[str] + ": " + ex.Message + ";
";
                }
            }
            return flag;
        }

然后在global文件中Application_Start的方法内开启一下线程池，用于遍历邮箱的队列，如果队列中有要发的邮件，则自动调用发送邮件的代码进行邮件发送。

代码如下：

protected void Application_Start(object sender, EventArgs e)
        {
            string basePath = AppDomain.CurrentDomain.BaseDirectory;
            //step 2: start a thread to scan email queue(send email)
            ThreadPool.QueueUserWorkItem((o) =>
            {
                while (true)
                {
                    try
                    {
                        if (EmailHelper.mailQueueLR.Count > 0)
                        {
                            lock (this)
                            {
                                if (EmailHelper.mailQueueLR.Count > 0)
                                {
                                    int tempInt = EmailHelper.mailQueueLR.Dequeue();
                                    if (tempInt == null || tempInt == 0)
                                    {
                                    }
                                    else
                                    {
                                      //此处为创建一个邮件的具体代码，根据实际情况编写
                                     }
                                        catch (Exception ex)
                                        {
                                            //this.AddMsg(exception.Message);
                                            string str = ex.Message;
                                            str = str + "str";

                                        }
                                    }
                                }
                            }
                        }
                        else
                        {
                            Thread.Sleep(1000);
                        }
                    }
                    catch (InvalidOperationException ioex)
                    {
                        continue;
                    }
                    catch (Exception ex)
                    {
                        continue;
                    }

                }
            }, basePath);
        }

 实际开发中遇到的问题

1：在Ipad或者iphone设备中出现了，接收到的邮件只显示源代码的情况。

     原因：在发送邮件时，实际是发送了两份，一份源代码，一份可选内容，而在ipad中却只显示了源代码

    解决方法：把所有的HTML代码都放到可变视图（AlternateViews）中去，不再放到body里面，

2：在邮件显示时，出现了乱码的情况。

    原因：邮件内容编码格式不统一，例如：正文内容跟标题编码格式不统一

    解决方法：统一编码格式，所有字符串都转换成相同编码格式