UIScrollView & UIPageControl - start on specific page in SWIFT - ios

Question

I have implemented an UIScrollView & UIpageControl to display 3 UIViewControllers.
It works very well but I want to start the display on the 2nd UIViewController.
I didn't find yet where is my fault:
var pageControl:UIPageControl!
var scrollView:UIScrollView!
var viewtest1:UIViewController!
var viewtest2:UIViewController!
var viewtest3:UIViewController!
override func viewDidLoad() {
super.viewDidLoad()
// Initialization of UIScrollView
self.scrollView = UIScrollView()
self.scrollView.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height)
self.scrollView.pagingEnabled = true
self.scrollView.scrollEnabled = true
self.scrollView.showsHorizontalScrollIndicator = false
self.scrollView.showsVerticalScrollIndicator = false
self.scrollView.delegate = self
// Initialisation of UIPageControl
self.pageControl = UIPageControl()
pageControl.currentPageIndicatorTintColor = UIColor(red:0.325, green:0.667, blue:0.922, alpha: 1)
pageControl.pageIndicatorTintColor = UIColor.whiteColor()
pageControl.backgroundColor = UIColor.clearColor()
// Add different view to the screen in the order from left to right
self.addChildViewController(self.viewtest1)
self.addChildViewController(self.viewtest2)
self.addChildViewController(self.viewtest3)
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
for var i=0; i < self.childViewControllers.count; i++ {
self.loadScrollViewWithPage(i)
}
self.pageControl.currentPage = 0
self.page = 0
self.pageControl.numberOfPages = self.childViewControllers.count
var viewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
if viewController.view.superview != nil {
viewController.viewWillAppear(true)
}
self.scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * CGFloat(self.childViewControllers.count), scrollView.frame.size.height)
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
// Load Controllers
var viewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
if viewController.view.superview != nil {
viewController.viewDidAppear(true)
}
}
override func viewWillDisappear(animated: Bool) {
var viewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
if viewController.view.superview != nil {
viewController.viewWillDisappear(true)
}
super.viewWillDisappear(true)
}
override func viewDidDisappear(animated: Bool) {
var viewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
if viewController.view.superview != nil {
viewController.viewDidDisappear(true)
}
super.viewDidDisappear(true)
}
func loadScrollViewWithPage(page:Int){
if page < 0 || page >= self.childViewControllers.count {
return
}
let controller:UIViewController = self.childViewControllers[page] as! UIViewController
if (controller == false) {
return
}
// add the controller's view to the scroll view
if (controller.view.superview == nil) {
var frame:CGRect = self.scrollView.frame
frame.origin.x = frame.size.width * CGFloat(page)
frame.origin.y = 0
controller.view.frame = frame
self.scrollView.addSubview(controller.view)
}
}
func changePage(sender:AnyObject) -> () {
var senderControl:UIPageControl = sender as! UIPageControl
var page:Int = Int(senderControl.currentPage)
// update the scroll view to the appropriate page
var frame:CGRect = self.scrollView.frame
frame.origin.x = frame.size.width * CGFloat(page)
frame.origin.y = 0
var oldViewController:UIViewController = self.childViewControllers[self.page] as! UIViewController
var newViewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
oldViewController.viewWillDisappear(true)
newViewController.viewWillAppear(true)
self.scrollView.scrollRectToVisible(frame, animated: true)
self.pageControlUsed = true
}
override func scrollViewDidEndScrollingAnimation(scrollView: UIScrollView) {
var oldViewController:UIViewController = self.childViewControllers[self.page] as! UIViewController
var newViewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
oldViewController.viewWillDisappear(true)
newViewController.viewWillAppear(true)
self.page = self.pageControl.currentPage
}
override func scrollViewDidScroll(scrollView: UIScrollView) {
if (self.pageControlUsed == true /*|| _rotating*/) {
// do nothing - the scroll was initiated from the page control, not the user dragging
return
}
var pageWidth:CGFloat = self.scrollView.frame.size.width
var page:Int = Int(floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1)
if (self.pageControl.currentPage != page) {
var oldViewController:UIViewController = self.childViewControllers[self.pageControl.currentPage] as! UIViewController
var newViewController:UIViewController = self.childViewControllers[page] as! UIViewController
oldViewController.viewWillDisappear(true)
newViewController.viewWillDisappear(true)
self.pageControl.currentPage = page
oldViewController.viewDidDisappear(true)
newViewController.viewDidDisappear(true)
self.page = page;
}
}
override func scrollViewWillBeginDragging(scrollView: UIScrollView) {
self.pageControlUsed = false
}
override func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
self.pageControlUsed = false
}
Thank you for your help

Answer 1

In storyboard set the "viewtest2" to "Is Initial View Controller". That will show that viewController first.
Or you can try in appDelegate :
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject :AnyObject]?) -> Bool {
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
var storyboard = UIStoryboard(name: "Main", bundle: nil)
var initialViewController = storyboard.instantiateViewControllerWithIdentifier("viewTest2") as UIViewController
self.window?.rootViewController = initialViewController
self.window?.makeKeyAndVisible()
}