Creating Outlook calendar invitations with SendGrid in Azure (C#, .NET)

问题

Been trying to find an example on how to create and send Outlook calendar invitations via SendGrid service and found none. I need the invitations to arrive as Outlook native invites rather than attachments too. A simple example or a link to one will help a lot!

回答1:

Recently had the same issue with Sendgrid through SMTP. Not the best, but working example:

 MailMessage mailMessage = new MailMessage();                
            mailMessage.From = new MailAddress(emailfrom); //from
            mailMessage.To.Add(new MailAddress(emailto)); //to
            mailMessage.Subject = subject;

            // check if message is meeting, if yes - attach meeting request as an alternateView
            if (isMeeting)
            {
                System.Net.Mime.ContentType contentType = new System.Net.Mime.ContentType("text/calendar");
                ct.Parameters.Add("method", "REQUEST");
                ct.Parameters.Add("name", "meeting.ics");
                string meetingInfo = MeetingRequestStrig(emailfrom, emailto, subject, bodycontent, location,
                    start.Value, end.Value, timezone, eventID, isCancel);
                AlternateView avCal = AlternateView.CreateAlternateViewFromString(meetingInfo, contentType);
                mailMessage.AlternateViews.Add(avCal);
            }
            else //otherwise sendgrid ignores calendar event and outlook has a simple html message
            {   
                mailMessage.Body = bodycontent;
            }                              
            mailMessage.IsBodyHtml = html_enable; //if you need it

            // SMTP client, AppSettings.*** - from web.config in this case
            SmtpClient mSmtpClient = new SmtpClient(AppSettings.SMTPHost, Convert.ToInt32(AppSettings.SMTP_Port));
            NetworkCredential credentials = new System.Net.NetworkCredential(AppSettings.SMTPUsername,
                    AppSettings.SMTPPassword);
                mSmtpClient.Credentials = credentials;

            //send 
            mSmtpClient.Send(mailMessage);

private static string MeetingRequestString(string from, string to, string subject, string desc, string location, DateTime startTime, DateTime endTime, TimeZoneInfo timezone, int? eventID = null, bool isCancel = false)
    {
        StringBuilder str = new StringBuilder();

        str.AppendLine("BEGIN:VCALENDAR");
        str.AppendLine("PRODID:-//Microsoft Corporation//Outlook 12.0 MIMEDIR//EN");
        str.AppendLine("VERSION:2.0");
        str.AppendLine(string.Format("METHOD:{0}", (isCancel ? "CANCEL" : "REQUEST")));
        str.AppendLine("BEGIN:VEVENT");

        int gapHours = GetTimeZoneOffsetHours(timezone);

        str.AppendLine(string.Format("DTSTART:{0:yyyyMMddTHHmmssZ}", startTime.AddHours(gapHours).ToUniversalTime()));
        str.AppendLine(string.Format("DTSTAMP:{0:yyyyMMddTHHmmss}", DateTime.Now));
        str.AppendLine(string.Format("DTEND:{0:yyyyMMddTHHmmssZ}", endTime.AddHours(gapHours).ToUniversalTime()));
        str.AppendLine(string.Format("LOCATION: {0}", location));
        str.AppendLine(string.Format("UID:{0}", (eventID.HasValue ? "blablabla" + eventID : Guid.NewGuid().ToString())));
        str.AppendLine(string.Format("DESCRIPTION:{0}", desc.Replace("\n", "<br>")));
        str.AppendLine(string.Format("X-ALT-DESC;FMTTYPE=text/html:{0}", desc.Replace("\n", "<br>")));
        str.AppendLine(string.Format("SUMMARY:{0}", subject));

        str.AppendLine(string.Format("ORGANIZER;CN=\"{0}\":MAILTO:{1}", from, from));
        str.AppendLine(string.Format("ATTENDEE;CN=\"{0}\";RSVP=TRUE:mailto:{1}", to, to));

        str.AppendLine("BEGIN:VALARM");
        str.AppendLine("TRIGGER:-PT15M");
        str.AppendLine("ACTION:DISPLAY");
        str.AppendLine("DESCRIPTION:Reminder");
        str.AppendLine("END:VALARM");
        str.AppendLine("END:VEVENT");
        str.AppendLine("END:VCALENDAR");

        return str.ToString();
    }

I hope this helps.

来源：https://stackoverflow.com/questions/36927038/creating-outlook-calendar-invitations-with-sendgrid-in-azure-c-net