calendarinvite.txt

using Ical.Net;
using Ical.Net.DataTypes;
using Ical.Net.Serialization.iCalendar.Serializers;
using Ical.Net.Serialization;
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MailMessage message = new MailMessage();
message.To.Add("naik899@gmail.com");
message.From = new MailAddress("info@company.com", "Company, Inc");
message.Subject = "subject";
message.Body = "emailbody";
message.IsBodyHtml = true;
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var calendar = new Ical.Net.Calendar();

foreach (var res in reg.Reservations) {
	calendar.Events.Add(new Event {
		Class = "PUBLIC",
		Summary = res.Summary,
		Created = new CalDateTime(DateTime.Now),
		Description = res.Details,
		Start = new CalDateTime(Convert.ToDateTime(res.BeginDate)),
		End = new CalDateTime(Convert.ToDateTime(res.EndDate)),
		Sequence = 0,
		Uid = Guid.NewGuid().ToString(),
		Location = res.Location,
	});
}

var serializer = new CalendarSerializer(new SerializationContext());
var serializedCalendar = serializer.SerializeToString(calendar);
var bytesCalendar = Encoding.UTF8.GetBytes(serializedCalendar);
MemoryStream ms = new MemoryStream(bytesCalendar);
System.Net.Mail.Attachment attachment = new System.Net.Mail.Attachment(ms, "event.ics", "text/calendar");

message.Attachments.Add(attachment);
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