I want to make a app which can create a new event and send it to other persons. So I thought it might be possible to create an ics-File of an EKEvent and send it away via em
There are no methods of EKEvent which allows you to save it to file. The only way I see is to create file on your own, it should have VCalendar format. Just save event to file from iCal and see what it has inside.
Late answer:
The file format is defined here: http://www.ietf.org/rfc/rfc2445.txt Since this is the official definition, it is a long document.
I suppose I'm late, but... I found a category that converts an EKEvent to an .ics file. I haven't tested yet: https://github.com/mysterioustrousers/EKEventToiCal