swift - 我的 VC 没有初始化器

Question

当我使用 XCode 6.1 时，一切都运行良好。在拥有 XCOde 6.3 之后，我遇到了委托(delegate)方法的问题。

之前:

protocol MainPageLoaderViewControllerDelegate{
    func changeCategoryOfSingelTopicViewController(category: Int!)
}

class MainPageLoaderViewController: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate, UIGestureRecognizerDelegate {

    var delegate: MainPageLoaderViewControllerDelegate?

    var categoryOfSingleTopic: Int! = 0 {
        didSet{        
            delegate?.changeCategoryOfSingelTopicViewController(categoryOfSingleTopic!)   
        }
    }    
}

现在，Complier 提示我 MainPageLoaderViewController 没有初始值设定项。我应该如何声明委托(delegate)变量？

全部代码:

import UIKit

protocol MainPageLoaderViewControllerDelegate{
    func changeCategoryOfSingelTopicViewController(category: Int!)
}
class MainPageLoaderViewController: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate, UIGestureRecognizerDelegate {


var delegate: MainPageLoaderViewControllerDelegate?

var categoryOfSingleTopic: Int! = 0{
    didSet{
        // put to the right column on pageviewcontroller
        movePageContentToViewControllerAtIndex(1)
        println("here is single topic \(categoryOfSingleTopic)")
        delegate?.changeCategoryOfSingelTopicViewController(categoryOfSingleTopic!)
        changeADVControleItemsName(categoryOfSingleTopic)
    }
}


let gestureRecognizerOfMainPageController: UIPanGestureRecognizer!

@IBOutlet var scrollContentView: UIView!

@IBOutlet var segmentControl: ADVSegmentedControl!

let transtionManger = TransitionManger()

var pageIndexTest: Int!

@IBOutlet var scrollView: UIScrollView!
var mainPageViewController : UIPageViewController!

var tableViewControllers = [UITableViewController]()
var newsLenta: UITableViewController!
var mainPage: SingleTopicTableViewController!
var onlinetranslation: UITableViewController!



  var identifiers:NSArray = ["MainPageContentViewController", "MainPageTableViewController", "SingleTopicTableViewController"]



var pageContentViewController: UITableViewController!

override func viewDidLoad() {
    super.viewDidLoad()




           // self.scrollView.scrollEnabled = false
    self.transtionManger.sourceViewController = self

    CommonFunctions.setBackgroundImageToNavBar(self.navigationItem)

    println("view did load of page controller loaded")

    segmentControl.thumbColor = Design.setColorGrey20()

    createArrayOfControllers()

    resetToMainPage(1)

    segmentControl.items = ["Лента", "Главная", "Онлайн"]
    segmentControl.font = UIFont(name: "Avenir-Black", size: 12)
    segmentControl.borderColor = UIColor(white: 1.0, alpha: 0.3)
    segmentControl.selectedIndex = 1
    segmentControl.selectedLabelColor = UIColor.whiteColor()


    setGestureRecognizerToTableView()
    self.transtionManger.segmentToSetInteraction = segmentControl





   scrollContentView.addGestureRecognizer(transtionManger.exitPanGesture)
   segmentControl.addTarget(self, action: "selectPageIndexBySegmentControl", forControlEvents: UIControlEvents.ValueChanged)

}

func changeADVControleItemsName(category:Int){

    switch category{
    case 0: segmentControl.items[1] = "Главная" // main
    case 100: segmentControl.items[1] = "Избранные" // saved
    case 1: segmentControl.items[1] = "Экономика" // economy
    case 2: segmentControl.items[1] = "Политика"  // politics
    case 4: segmentControl.items[1] = "Общество"  // community
    case 5: segmentControl.items[1] = "Спорт"  // sport
    case 6: segmentControl.items[1] = "Культура"  // culture
    case 8: segmentControl.items[1] = "Проишествия" // events
    case 10: segmentControl.items[1] = "Авто"  // auto
    case 11: segmentControl.items[1] = "Фото"  // photo
    case 12: segmentControl.items[1] = "Видео"  // video
    default: break

    }

}

func changeCategoryOfSingelTopicViewController(category: Int!){

}

func setGestureRecognizerToTableView(){
    self.transtionManger.tableViewFromSourceView = self.viewControllerAtIndex(segmentControl.selectedIndex) // we do it in order to disable table view until the menu is opened

}

func movePageContentToViewControllerAtIndex(index: Int){

    switch index {
    case 0:
        println("zero index were selected")
        pageContentViewController = self.viewControllerAtIndex(index)

        mainPageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.Forward , animated: true, completion: nil)

        setGestureRecognizerToTableView()
        setExitPaGestureAtViewControllerWithIndex(segmentControl.selectedIndex)
       // segmentControl.selectedIndex = index
    case 1:
        println("first element were selected")
        pageContentViewController = self.viewControllerAtIndex(index)

        mainPageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.Forward, animated: true, completion: nil)

        setGestureRecognizerToTableView()
        setExitPaGestureAtViewControllerWithIndex(segmentControl.selectedIndex)
           segmentControl.selectedIndex = index
    case 2:
        println("second element were selected")

        pageContentViewController = self.viewControllerAtIndex(index)
        mainPageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.Forward, animated: true, completion: nil)

        setGestureRecognizerToTableView()
        setExitPaGestureAtViewControllerWithIndex(segmentControl.selectedIndex)
    default: break
    }

}

func selectPageIndexBySegmentControl(){

    switch segmentControl.selectedIndex {
    case 0:
      movePageContentToViewControllerAtIndex(0)
    case 1:
       movePageContentToViewControllerAtIndex(1)
    case 2:
        movePageContentToViewControllerAtIndex(2)
    default:
        break
    }

}



@IBAction func showOrCloseMenu(sender: AnyObject) {
    if transtionManger.isMenuVisible == true {
        println("it is true")
        transtionManger.isMenuVisible = false

        transtionManger.menuViewController.performSegueWithIdentifier("dismisMenu", sender: nil)
    }
    else{
        println("it is false")
        performSegueWithIdentifier("showMenu", sender: nil)
    }
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    let menu = segue.destinationViewController as! SideBarMenuTableViewController

    if transtionManger.isMenuVisible == true {
        transtionManger.presentingP = false
    }

    menu.transitioningDelegate = self.transtionManger

    // add in order to set menuviewcontroller in transformerManager
    self.transtionManger.menuViewController = menu


}

@IBAction func unwindSegueToMainScreen(segue:UIStoryboardSegue) {
    // bug? exit segue doesn't dismiss so we do it manually...
    self.dismissViewControllerAnimated(true, completion: nil)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func createArrayOfControllers(){

    newsLenta = self.storyboard?.instantiateViewControllerWithIdentifier("NewsLentaTableViewController")as! NewsLentaTableViewController

    mainPage = self.storyboard?.instantiateViewControllerWithIdentifier("SingleTopicTableViewController") as! SingleTopicTableViewController

    self.delegate = mainPage

    onlinetranslation = self.storyboard?.instantiateViewControllerWithIdentifier("MainPageTableViewController") as! MainPageTableViewController

    tableViewControllers = [newsLenta, mainPage, onlinetranslation]
}

func resetToMainPage(index: Int!) {
    /* Getting the page View controller */
    mainPageViewController = self.storyboard?.instantiateViewControllerWithIdentifier("MainPageViewController") as! UIPageViewController
    self.mainPageViewController.dataSource = self
    self.mainPageViewController.delegate = self

    pageContentViewController = self.viewControllerAtIndex(index)

   // pageContentViewController.view.addGestureRecognizer(transtionManger.exitPanGesture3)
   // self.transtionManger.sourceViewController = pageContentViewController // adding swipe to the pageContentViewControlle in order to close menu
    //self.transtionManger.sourceViewController = mainPageViewController
    self.mainPageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.Forward, animated: true, completion: nil)


    self.mainPageViewController.view.frame = CGRectMake(0, 102, self.view.frame.width, self.view.frame.height)
    self.addChildViewController(mainPageViewController)
    self.view.addSubview(mainPageViewController.view)
    self.mainPageViewController.didMoveToParentViewController(self)

}

func viewControllerAtIndex(index : Int) -> UITableViewController? {

    if index > 2 || index < 0 {
        return nil
    }


    return tableViewControllers[index]
}

func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {

    var index:Int!

    if viewController.isKindOfClass(NewsLentaTableViewController) {

        index = (viewController as! NewsLentaTableViewController).pageIndex

    }else if viewController.isKindOfClass(MainPageTableViewController) {

       index = (viewController as! MainPageTableViewController).pageIndex

    }else if viewController.isKindOfClass(SingleTopicTableViewController) {

        index = (viewController as! SingleTopicTableViewController).pageIndex


    }else {return nil}

    if index == 2 {

        return nil

    }

    index = index + 1

    return self.viewControllerAtIndex(index)
}


func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {

    var index:Int!

    if viewController.isKindOfClass(NewsLentaTableViewController) {

        index = (viewController as! NewsLentaTableViewController).pageIndex

    }else if viewController.isKindOfClass(MainPageTableViewController) {

        index = (viewController as! MainPageTableViewController).pageIndex


    }else if viewController.isKindOfClass(SingleTopicTableViewController) {

        index = (viewController as! SingleTopicTableViewController).pageIndex

    }else {return nil}

    if index == 0 {
        return nil
    }
    index = index - 1

    return self.viewControllerAtIndex(index)

}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int
{
    return 2
}

func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int
{
    return thePageIndex
}

func pageViewController(pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [AnyObject], transitionCompleted completed: Bool) {
    if completed && finished {
        var index = previousViewControllers.startIndex

        segmentControl.selectedIndex = thePageIndex
        // add exit3 gesture recognizer to the current index
        setExitPaGestureAtViewControllerWithIndex(segmentControl.selectedIndex)
        setGestureRecognizerToTableView()
         //selectedLabelFrame
        //setContentOffSetOfUIScrollView()
    }
}

override func viewDidAppear(animated: Bool) {
     //setContentOffSetOfUIScrollView() // in the first load of view you need to set segment scroll
    setExitPaGestureAtViewControllerWithIndex(segmentControl.selectedIndex)

}

func setExitPaGestureAtViewControllerWithIndex(index: Int!){

    self.viewControllerAtIndex(index)?.tableView.addGestureRecognizer(transtionManger.exitPanGesture3)
}


func setContentOffSetOfUIScrollView(){
    println(segmentControl.items.count - 1)
    if thePageIndex == 0 {

        scrollView.setContentOffset(CGPointMake(0, 0), animated: true)
        return
    }else if thePageIndex == segmentControl.items.count - 1{
        if selectedLabelFrame.frame.origin.x + selectedLabelFrame.frame.width > self.view.frame.width {

            var sum = selectedLabelFrame.frame.origin.x + selectedLabelFrame.frame.width
            var scroll = sum - self.view.frame.width
            scrollView.setContentOffset(CGPointMake(scroll, 0), animated: true)
            return
        }else {
            var sum = selectedLabelFrame.frame.origin.x + selectedLabelFrame.frame.width
            var scroll = self.view.frame.width - sum
            scrollView.setContentOffset(CGPointMake(scroll, 0), animated: true)
            return
        }
    }

    if selectedLabelFrame.frame.origin.x + selectedLabelFrame.frame.width  > self.view.frame.width / 2 {
        println(selectedLabelFrame.frame.origin.x)
        println(selectedLabelFrame.frame.width)
        println(self.view.frame.width)
        println("more")
        if thePageIndex == 1 {

            var averageWidth = selectedLabelFrame.frame.width/2
            var sum = selectedLabelFrame.frame.origin.x + averageWidth
            var scroll = sum - self.view.frame.width/2
            println("scroll is \(scroll)")
            scrollView.setContentOffset(CGPointMake(scroll, 0), animated: true)

        }
    }else{
        println(selectedLabelFrame.frame.origin.x)
        println(selectedLabelFrame.frame.width)
        println(self.view.frame.width)
        println("less")
        if thePageIndex == 1 {

            var averageWidth = selectedLabelFrame.frame.width/2
            var sum = selectedLabelFrame.frame.origin.x + averageWidth
            var scroll = self.view.frame.width/2 - sum
            println("scroll is \(scroll)")
            scrollView.setContentOffset(CGPointMake(scroll, 0), animated: true)

        }
    }

}

Answer 1

在 Swift 中，所有实例变量都必须在 init 中初始化(参见 documentation)。在您添加 delegate 之前，您的 superview 的初始化器被调用(因为您没有覆盖它)并且您没有添加任何新的实例变量，所以这很好。然而，现在正在调用您的 superview 的实现，但它没有初始化您的变量，这是一个编译器错误。

两种选择:

1) 只需在声明中初始化:var delegate: MainPageLoaderViewControllerDelegate? = 无 2) 覆盖 init 并在那里初始化你的变量。