I'm a beginner in C# (and any networking code to be honest). I'm trying to send a calendar invite, that will be wired when you click a button on the company's website. This is a typical n-tier system, using asp.net/C# and SQL.
We used to simply generate an ics that the user would then have to know to open with Outlook, but I've since learned how to manually code a VCALENDAR so it shows up right away in Outlook nice and neat.
It's all been going fairly smoothly, but I would now like the body of the calendar invite to be able to accept HTML, to attach links in particular. I've experimented with AlternateViews, but it seems that the "X-ALT-DESC" attribute inside of VCALENDAR should do exactly what I want. However, try as I may Outlook ignores it and uses the description. There is clearly something I am missing.
(To clarify, everything works & compiles, except for the HTML alt description)
private Guid? CreateEmail()
{
Guid eventGuid = Guid.NewGuid();
MailMessage msg = new MailMessage();
msg.IsBodyHtml = true;
msg.From = new MailAddress("fromemail", "From Name");
msg.To.Add(toEmail);
msg.Subject = subject;
StringBuilder s = new StringBuilder();
s.AppendLine("BEGIN:VCALENDAR");
s.AppendLine("VERSION:2.0");
s.AppendLine("PRODID:-//My Product//Outlook MIMEDIR//EN");
s.AppendLine("METHOD:" + method); //In this case, "REQUEST"
s.AppendLine("STATUS:" + status.status); //"CONFIRMED"
s.AppendLine("BEGIN:VEVENT");
s.AppendLine("UID:" + eventGuid.ToString());
s.AppendLine("PRIORITY" + status.priority); //3
s.AppendLine("X-MICROSOFT-CDO-BUSYSTATUS:" + ShowAs.ToString()); //"BUSY"
s.AppendLine("SEQUENCE:" + UpdateNumber);//0
s.AppendLine("DTSTAMP:" + DateTime.Now.ToUniversalTime().ToString());
s.AppendLine("DTSTART:" + DateTimetoCalTime(startTime));
s.AppendLine("DTEND:" + DateTimetoCalTime(endTime));
s.AppendLine("SUMMARY:" + subject);
s.AppendLine("LOCATION: " + location);
s.AppendLine("DESCRIPTION: " + "Plain simple description"
string html_begin = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2//EN\">" +
"\n<html>" +
"\n<head>" +
"\n<title></title>" +
"\n</head>" +
"\n<body>" +
"\n<!-- Converted from text/rtf format -->\n\n<P DIR=LTR><SPAN LANG=\"en-us\">" +
"\n<Font face=\"Times New Roman\"";
body = "I simply <b> want some bold </b> here 555";
string html_end = "</font></span></body>\n</html>";
string html_body = html_begin + body + html_end;
msg.Body = html_body;
s.AppendLine("X-ALT-DESC;FMTTYPE=text/html:" + html_body);
msg.Body = html_body;
s.AppendLine("X-ALT_DESC;FMTTYPE=text/html:" + html_body);
s.AppendLine("STATUS:" + status.status); //"CONFIRMED"
s.AppendLine("BEGIN:VALARM");
s.AppendLine("TRIGGER:-PT1440M");
s.AppendLine("ACTION:Accept");
s.AppendLine("DESCRIPTION:Reminder");
s.AppendLine("END:VALARM");
s.AppendLine("END:VEVENT");
s.AppendLine(string.Format("ATTENDEE;CN=\"{0}\";RSVP=TRUE:mailto:{1}", msg.To[0].DisplayName, msg.To[0].Address));
s.AppendLine("END:VCALENDAR");
System.Net.Mime.ContentType type = new System.Net.Mime.ContentType("text/calendar");
type.Parameters.Add("method", method);
type.Parameters.Add("name", "meeting.ics");
msg.AlternateViews.Add(AlternateView.CreateAlternateViewFromString(s.ToString(), type));
SMTP.send(msg);
return EventGuid;
Produces this body in outlook:
<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 3.2//EN”>
<html>
<head>
<title></title>
</head>
<body>
<!-- Converted from text/rtf format -->
<P DIR=LTR><SPAN LANG=”en-us”>
<Font face=”Times New Roman”I simply <b> want some bold </b> here 555</font></span></body>
</html>
From testing: If I leave Msg.body out, it just used the "DESCRIPTION". If I make it equal the HTML, I get the above result.
Thank You!
You can have X-ALT-DESC on multiple lines, you just need to add a space on the beginning of each lines following it.
Lines of text SHOULD NOT be longer than 75 octets, excluding the line break. Long content lines SHOULD be split into a multiple line representations using a line "folding" technique. That is, a long line can be split between any two characters by inserting a CRLF immediately followed by a single linear white-space character (i.e., SPACE or HTAB). Any sequence of CRLF followed immediately by a single linear white-space character is ignored (i.e., removed) when processing the content type.
https://icalendar.org/iCalendar-RFC-5545/3-1-content-lines.html