Distributing RDLC output as an email attachment

Question

Our winforms application has long allowed a "print" option which basically uses RDLC.

The customer has requested that we add a feature allowing users to send the "printed" output via email.

Now, we know that an EMF file is created (in the TEMP folder) as a sort of hidden byproduct of our current printing process.

Seems to us we can simply grab this EMF file and attach it to a new email and the job is done.

1. Is this the best option?
2. Can we rely on an EMF file be opened by any Windows machine?
3. How we identify the EMF file? ... just seems to be named %TEMP%\DiaryGrid_1.emf currently. OK so DiaryGrid is the name of our RDLC file but the _1 gets added somewhere along the way.

Answer 1

I did it before. I did it exporting programatically the report to a pdf to a specific location, then we email the pdf file and delete it. I will try to find the code for you (Not in home now)

EDITED:

Sorry for the later. Now i'm in home and I will give you some code blocks that I think will give you some help to acomplish your task. I will include some comments to the code so you can understand some things that are specific in my project. This code are tested and are working well in my clients, but i'm sure that it can be improved. Please, let me know if you can improve this code ;)

First of all, we will export the report to pdf.

private string ExportReportToPDF(string reportName)
{
   Warning[] warnings;
   string[] streamids;
   string mimeType;
   string encoding;
   string filenameExtension;
   byte[] bytes = ReportViewer1.LocalReport.Render(
      "PDF", null, out mimeType, out encoding, out filenameExtension,
       out streamids, out warnings);

   string filename = Path.Combine(Path.GetTempPath(), reportName);
   using (var fs = new FileStream(filename, FileMode.Create))
   {
      fs.Write(bytes, 0, bytes.Length);
      fs.Close();
   }

   return filename;
}

Now, we need a class that control the Mail system. Every mail system has their own caracteristics, so maybe you will need modify this class. The behaviour of the class is simple. You only need to fill the properties, and call the Send method. In my case, windows don't let me delete the pdf file once I send it (Windows says the file is in use), so I program the file to be deleted in the next reboot. Take a look to the delete method. Please, note that the send method use a cutom class named MailConfig. This is a small class that has some config strings like Host, User Name, and Password. The mail will be send using this params.

public class Mail
{
   public string Title { get; set; }
   public string Text { get; set; }
   public string From { get; set; }
   public bool RequireAutentication { get; set; }
   public bool DeleteFilesAfterSend { get; set; }

   public List<string> To { get; set; }
   public List<string> Cc { get; set; }
   public List<string> Bcc { get; set; }
   public List<string> AttachmentFiles { get; set; }

   #region appi declarations

   internal enum MoveFileFlags
   {
      MOVEFILE_REPLACE_EXISTING = 1,
      MOVEFILE_COPY_ALLOWED = 2,
      MOVEFILE_DELAY_UNTIL_REBOOT = 4,
      MOVEFILE_WRITE_THROUGH = 8
   }

   [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
   static extern bool MoveFileEx(string lpExistingFileName,
                                 string lpNewFileName,
                                 MoveFileFlags dwFlags);

   #endregion

   public Mail()
   {
      To = new List<string>();
      Cc = new List<string>();
      Bcc = new List<string>();
      AttachmentFiles = new List<string>();
      From = MailConfig.Username;
   }

   public void Send()
   {
      var client = new SmtpClient
      {
         Host = MailConfig.Host,
         EnableSsl = false,
      };

      if (RequireAutentication)
      {
         var credentials = new NetworkCredential(MailConfig.Username, 
                                                 MailConfig.Password);
         client.Credentials = credentials;
      }

      var message = new MailMessage
      {
         Sender = new MailAddress(From, From),
         From = new MailAddress(From, From)
      };

      AddDestinataryToList(To, message.To);
      AddDestinataryToList(Cc, message.CC);
      AddDestinataryToList(Bcc, message.Bcc);

      message.Subject = Title;
      message.Body = Text;
      message.IsBodyHtml = false;
      message.Priority = MailPriority.High;

      var attachments = AttachmentFiles.Select(file => new Attachment(file));
      foreach (var attachment in attachments)
         message.Attachments.Add(attachment);

      client.Send(message);

      if (DeleteFilesAfterSend)
         AttachmentFiles.ForEach(DeleteFile);
   }

   private void AddDestinataryToList(IEnumerable<string> from,
      ICollection<MailAddress> mailAddressCollection)
   {
      foreach (var destinatary in from)
         mailAddressCollection.Add(new MailAddress(destinatary, destinatary));
   }

   private void DeleteFile(string filepath)
   {
      // this should delete the file in the next reboot, not now.
      MoveFileEx(filepath, null, MoveFileFlags.MOVEFILE_DELAY_UNTIL_REBOOT);
   }
}

Now, you can create a form to ask for the destinataries, add some validation, etc, return to you an instance of the Mail class... or you can simply "hard code" the values and fill the class.

Here is the code that I use in a button to call this form, in my example it is named SendMailView.

private void BtnSendByMail_Click(object sender, EventArgs e)
{
   SendMailView sendMailView = new SendMailView();

   if (sendMailView.ShowDialog()== DialogResult.OK)
   {
      Mail mail = sendMailView.CurrentItem;
      mail.AttachmentFiles.Add(ExportReportToPDF("Invoice.pdf"));
      mail.DeleteFilesAfterSend = true;
      mail.RequireAutentication = true;
      mail.Send();
   }
   sendMailView.Dispose();
}

In this example senMailView.CurrentItem is the instance of the mail class. We simply need to call to the Send methis and the work is done.

This is the largest answer I ever wrote in SO... I hope it help you :D If you have any problem using it, call me. By the way, i'm not very proud of my english, so forgive me if the text has any mistake.