问收集txt文件并发送电子邮件

EN

                    MailMessage mail = new MailMessage();
                    SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");
                    mail.From = new MailAddress("******");
                    mail.To.Add("********");
                    mail.Subject = "Test Mail - 1";
                    mail.Body = "mail with attachment";


                    string folder = @"C:\files";
                    string[] txtfiles = Directory.GetFiles(folder, "*.txt");


                    *foreach( txtfiles in folder )*  
                      // this where my problem lies im trying to loop through directory                   //files and then add as attachment

                    {

                    System.Net.Mail.Attachment attachment;
                    attachment = new System.Net.Mail.Attachment(folder);
                    mail.Attachments.Add(attachment);

                    SmtpServer.Port = 587;
                    SmtpServer.Credentials = new System.Net.NetworkCredential("*****", "******");
                    SmtpServer.EnableSsl = true;

                    SmtpServer.Send(mail);


                    }


                    }

                  }