【发布时间】：2015-07-30 12:04:52
【问题描述】：
我是协议和页面浏览控制器的新手，我尝试了一些我希望很简单的东西。要将变量值从内容视图控制器传递到页面列表视图控制器，但它不起作用所以我做错了什么......
在我的故事板中，我有一个 ViewController（作为页面列表视图控制器）并嵌入在导航控制器中。导航栏上有一个按钮。
有一个 PageContentViewController 有一个标签。
我使用的代码如下（使用@Tom Elliott 提供的公认解决方案编辑）：
protocol setRoomOnScreenProtocol {
func updateRoomOnScreen(myRoom: String)
}
class ViewController: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate, setRoomOnScreenProtocol {
@IBAction func press1(sender: AnyObject) {
println("roomOnScreen: \(roomOnScreen)")
println("pageTitles: \(pageTitles)")
}
@IBOutlet weak var btn1: UIBarButtonItem!
let pageTitles = ["Room 1", "Room 2", "Room 3", "Room 4"]
var count = 0
var pageViewController : UIPageViewController!
var roomOnScreen: String = ""
override func viewDidLoad() {
super.viewDidLoad()
reset()
}
func updateRoomOnScreen(myRoom: String) {
roomOnScreen = myRoom
println("roomOnScreen (PGL): \(roomOnScreen)")
}
func reset() {
/* Getting the page View controller */
pageViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageViewController") as! UIPageViewController
self.pageViewController.dataSource = self
let pageContentViewController = self.viewControllerAtIndex(0)
self.pageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.Forward, animated: true, completion: nil)
self.pageViewController.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height)
self.addChildViewController(pageViewController)
self.view.addSubview(pageViewController.view)
self.pageViewController.didMoveToParentViewController(self)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
var index = (viewController as! PageContentViewController).pageIndex!
index++
return self.viewControllerAtIndex(index)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
var index = (viewController as! PageContentViewController).pageIndex!
if (index <= 0) {
return nil
}
index--
return self.viewControllerAtIndex(index)
}
func viewControllerAtIndex(index : Int) -> UIViewController? {
if ((self.pageTitles.count == 0) || (index >= self.pageTitles.count)) {
return nil
}
let pageContentViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageContentViewController") as! PageContentViewController
pageContentViewController.delegate = self
pageContentViewController.titleText = self.pageTitles[index]
pageContentViewController.pageIndex = index
return pageContentViewController
}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
return pageTitles.count
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
return 0
}
}
和 PageContentViewController：
class PageContentViewController: UIViewController {
var pageIndex: Int?
var titleText : String!
var delegate: setRoomOnScreenProtocol!
@IBOutlet weak var label1: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
self.label1.text = self.titleText
}
override func viewDidAppear(animated: Bool) {
if let actualDelegate = self.delegate {
actualDelegate.updateRoomOnScreen(titleText)
} else {
println("error")
}
doMore()
}
func doMore() {
println("showing...:\(titleText)")
}
}
当我浏览页面时，我正确地得到了输出：
roomOnScreen (PGL): Room 1
showing...:Room 1
roomOnScreen (PGL): Room 2
showing...:Room 2
但是当我点击导航栏按钮时，我没有得到任何价值......
roomOnScreen:
pageTitles: [Room 1, Room 2, Room 3, Room 4]
我做错了什么...？
谢谢！
【问题讨论】：
标签： ios swift uiviewcontroller protocols uipageviewcontroller