类没有初始值设定项（Xcode 6.3）

尝试在更新到Xcode 6.3后找出错误。我有一个类出现了错误“类没有初始值设定项”谁能告诉我如何修复这个问题

class TodayViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, BWWalkthroughViewControllerDelegate {


var events: [EKEvent] = []
let eventStore = EKEventStore()
var pttCalendar: EKCalendar?

let walkthroughVC : BWWalkthroughViewController?

@IBOutlet weak var tableView: UITableView!

var dateFormatter = NSDateFormatter()

override func viewDidLoad() {
    super.viewDidLoad()

    requestCalendarAccess()

    let firstLaunch = NSUserDefaults.standardUserDefaults().boolForKey("FirstLaunch")
    if firstLaunch  {
        println("Not first launch.")
    }
    else {
        showWalkthrough()
        println("First launch, setting NSUserDefault.")
        NSUserDefaults.standardUserDefaults().setBool(true, forKey: "FirstLaunch")
    }


    self.tableView.rowHeight = 50

    dateFormatter.dateFormat = "EE, MMM dd"
    let dateForLabel = dateFormatter.stringFromDate(NSDate())

    self.title = dateForLabel
}

---

您忘记了override func init

您需要一个初始化器来设置该值

let walkthroughVC : BWWalkthroughViewController?

将其设置为var将删除错误。它当然会默认为零