ASP.NET MVC 生成EML文件

需求: 点发送邮件按钮的时候, 自动在客户端电脑打开默认邮件的窗口,并且把内容和附件都附加上去.

解决方案: 尝试使用过Microsoft.Office.Interop.Outlook 和 MPAI.dll 都无法实现, 在本地debug的时候是完全没问题的, 但是部署到IIS上后发现 这两个方式都会在服务器上寻找默认的邮件客户端. 显然这个不能实现的。

Mailto :方法可行, 也可以打开默认的邮件客户端,但是无法添加附件。 

最后只能在Controller里面生成EML文件

注意: 在这里我曾使用过MomeyStream 直接作为附件, 但是提示文件损坏. 后面没有时间就没有继续研究了,. 目前是保存到服务器的一个文件夹里面. 

下面是实现的代码:

Helper:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Net.Mail;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Web.Mvc;

namespace AgilityNorthAsiaPlatform.Code.Helpers
{
    public class MailHelper
    {
     
        public static void ToEmlStream(System.Net.Mail.MailMessage msg, Stream str, string dummyEmail)
        {
            using (var client = new SmtpClient())
            {
                var id = Guid.NewGuid();

                var tempFolder = Path.Combine(Path.GetTempPath(), Assembly.GetExecutingAssembly().GetName().Name);

                tempFolder = Path.Combine(tempFolder, "MailMessageToEMLTemp");

                // create a temp folder to hold just this .eml file so that we can find it easily.
                tempFolder = Path.Combine(tempFolder, id.ToString());

                if (!Directory.Exists(tempFolder))
                {
                    Directory.CreateDirectory(tempFolder);
                }

                client.UseDefaultCredentials = true;
                client.DeliveryMethod = SmtpDeliveryMethod.SpecifiedPickupDirectory;
                client.PickupDirectoryLocation = tempFolder;
                client.Send(msg);

                // tempFolder should contain 1 eml file
                var filePath = Directory.GetFiles(tempFolder).Single();

                // create new file and remove all lines that start with 'X-Sender:' or 'From:'
                string newFile = Path.Combine(tempFolder, "modified.eml");
                using (var sr = new StreamReader(filePath))
                {
                    using (var sw = new StreamWriter(newFile))
                    {
                        string line;
                        while ((line = sr.ReadLine()) != null)
                        {
                            if (!line.StartsWith("X-Sender:") &&
                                !line.StartsWith("From:") &&
                                // dummy email which is used if receiver address is empty
                                !line.StartsWith("X-Receiver: " + dummyEmail) &&
                                // dummy email which is used if receiver address is empty
                                !line.StartsWith("To: " + dummyEmail))
                            {
                                sw.WriteLine(line);
                            }
                        }
                    }
                }

                // stream out the contents
                using (var fs = new FileStream(newFile, FileMode.Open))
                {
                    fs.CopyTo(str);
                }
            }
        }

        public static string ReadSignature()
        {
            string appDataDir = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "\Microsoft\Signatures";
            string signature = string.Empty;
            DirectoryInfo diInfo = new DirectoryInfo(appDataDir);
            if
            (diInfo.Exists)
            {
                FileInfo[] fiSignature = diInfo.GetFiles("*.htm");

                if (fiSignature.Length > 0)
                {
                    StreamReader sr = new StreamReader(fiSignature[0].FullName, Encoding.Default);
                    signature = sr.ReadToEnd();
                    if (!string.IsNullOrEmpty(signature))
                    {
                        string fileName = fiSignature[0].Name.Replace(fiSignature[0].Extension, string.Empty);
                        signature = signature.Replace(fileName + "_files/", appDataDir + "/" + fileName + "_files/");
                    }
                }

            }
            return signature;
        }



    }
}

　Controller 

public FileStreamResult ModalSendMail()
        {

            var report = new rpt_CFS_ShipmentReport_1();
            report.ajs_Param.Value = (string)LocalViewData["SendMail_Json"];
            report.as_Table.Value = "Con_Shp";
            report.as_UsrID.Value = User.Identity.Name;

            var ReportStream = new MemoryStream();
            report.ExportToPdf(ReportStream);

            string ls_filename = "Shipment Report" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".pdf";
            try
            {
                report.ExportToPdf(ReportStream);
                FileStream fs = null;
                fs = new FileStream(Path.Combine(Server.MapPath("~/FileUploads/"), ls_filename), FileMode.CreateNew);
                fs.Write(ReportStream.GetBuffer(), 0, ReportStream.GetBuffer().Length);
                fs.Flush();
                fs.Close();
                ReportStream.Flush();
                ReportStream.Close();
            }
            catch (Exception ex)
            {

            }

            string dummyEmail = User.Identity.Name+"@xxx.com";
            var mailMessage = new MailMessage();
            mailMessage.To.Add(new MailAddress("xxx@xxx.com"));
            mailMessage.From = new MailAddress(dummyEmail);
            mailMessage.Subject = "Test subject";
            mailMessage.IsBodyHtml = true;
            mailMessage.Body = "Test body" + MailHelper.ReadSignature();
   
            // mark as draft
            mailMessage.Headers.Add("X-Unsent", "1");

            // download image and save it as attachment
            using (var httpClient = new HttpClient())
            {
                //download file from HTTP:
                //var imageStream = await httpClient.GetStreamAsync(new Uri(Path.Combine(Server.MapPath("~/FileUploads/"), ls_filename)));
                //mailMessage.Attachments.Add(new Attachment(HttpContext.Server.MapPath("~/App_Data/Test.docx")));
                mailMessage.Attachments.Add(new System.Net.Mail.Attachment(Path.Combine(Server.MapPath("~/FileUploads/"), ls_filename), MediaTypeNames.Application.Pdf));
            }
            var stream = new MemoryStream();
             MailHelper.ToEmlStream(mailMessage, stream, "jahe@agility.com");
            stream.Position = 0;
            return File(stream, "message/rfc822", "test_email.eml");
        }