尝试添加事件时出现“未设置日历”

Question

我正在使用下面的代码，但是每当我尝试在EKEventStore中添加事件时，都会引发此错误“未设置日历”

func createEvent(with title: String, isAllDay: Bool, notes: String? = "", location: String? = "") {

    store.requestAccess(to: .event) { (granted, error) in
        if error != nil {
            print(error?.localizedDescription ?? "error occured")
            return
        }
        self.store = EKEventStore()
        let event = EKEvent(eventStore: self.store)
        event.title = title
        event.startDate = self.selectedStartDate
        event.endDate = self.selectedEndDate
        event.isAllDay = isAllDay
        event.notes = notes
        event.location = location
        do {
            try self.store.save(event, span: .thisEvent, commit: true)
            print(event.eventIdentifier) //save event id to access this particular event later
        } catch let errorThis {
            print("cant add event with this error -> \(errorThis.localizedDescription)")
        }
    }
}