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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!
332
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
182
I found that the HTML string must be all on one line. If the HTML is broken over multiple lines, that does not conform to Vcalendar encoding and the description is either rendered as a blank page or as plain text with all HTML tags visible.
I've seen others out there claiming that the DESCRIPTION tag must be used in front of "X-ALT-DESC;FMTTYPE=text/html:". This is totally WRONG and FALSE. If "DESCRIPTION" exists, it takes precedence, the "X-ALT-DESC;FMTTYPE=text/html:" line is completely ignored by Outlook and the plain text description is rendered. Therefore, "X-ALT-DESC;FMTTYPE=text/html:" must stand on it's own and be on it's own line.
Working example:
... X-ALT-DESC;FMTTYPE=text/html:<html><body><a href="http://bing.com">Bing</a></body></html> ...
Wrong:
... DESCRIPTION;X-ALT-DESC;FMTTYPE=text/html:<html><body><a href="http://bing.com">Bing</a></body></html> ...
Wrong again:
... X-ALT-DESC;FMTTYPE=text/html:<html> <body> <a href="http://bing.com">Bing</a> </body> </html> ...
28
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