问题
Currently I'm working on a icalendar for the calendar app of apple. When i dived deeper in the icalendars i found some X- extensions. Does someone know how the X-APPLE-STRUCTURED-LOCATION , X-APPLE-TRAVEL-DURATION AND X-APPLE-TRAVEL-START work? Here are some exemples:
BEGIN:VCALENDAR
CALSCALE:GREGORIAN
VERSION:2.0
METHOD:PUBLISH
X-WR-CALNAME:test 2
X-WR-TIMEZONE:Europe/Amsterdam
X-APPLE-CALENDAR-COLOR:#FF2968
BEGIN:VEVENT
TRANSP:OPAQUE
DTEND:20150617T193000Z
UID:test@webscoding.nl
DTSTAMP:20150617T183000Z
LOCATION:Olympus 1\n3524 WB Utrecht\nThe Netherlands
DESCRIPTION:Paulien Prent en Danielle Roumen vs. Rosa van Heesch en Lari
ssa Nijholt
SEQUENCE:0
X-APPLE-TRAVEL-START;ROUTING=CAR;VALUE=URI;X-ADDRESS=Bingerdenallee 1\\n
6921 JN Duiven\\nNederland;X-TITLE=Home:
TRIGGER:
X-APPLE-TRAVEL-DURATION;VALUE=DURATION:PT45M
SUMMARY:[Tennis wedstrijd] DD 17+ A
DTSTART:20150617T183000Z
CREATED:20150616T223112Z
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=Olympus 1\\n3524 WB Utre
cht\\nThe Netherlands;X-APPLE-RADIUS=49.91307222863458;X-TITLE=Olympus 1
:geo:52.063921,5.128511
BEGIN:VALARM
X-WR-ALARMUID:CDABC4A5-8430-48C7-8AF4-4F031DD57C6A
UID:CDABC4A5-8430-48C7-8AF4-4F031DD57C6A
TRIGGER;X-APPLE-RELATED-TRAVEL=-PT30M:-PT1H15M
DESCRIPTION:Event reminder
ACTION:DISPLAY
END:VALARM
END:VEVENT
END:VCALENDAR
来源：https://stackoverflow.com/questions/30921899/how-do-the-x-apple-extensions-work-in-icalendars