page based application overload memory ARC don´t release pages - ios

Question

may you can help me with this memory issue. So I builded a app based on the project preset "Page-Based Application" everything works well, but over time the single views load every Viewcontroller into the physical memory and don´t release them. If the memory is full the app will crash.
here ist my code:
The RootViewController (CatalougeViewController):
import UIKit
class CatalougeViewController: UIViewController, UIPageViewControllerDelegate, UIGestureRecognizerDelegate {
var pageViewController: UIPageViewController?
var zoomTransform: CGAffineTransform?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
// Configure the page view controller and add it as a child view controller.
self.pageViewController = UIPageViewController(transitionStyle: .PageCurl, navigationOrientation: .Horizontal, options: nil)
self.pageViewController!.delegate = self
let startingViewController: DataViewController = self.modelController.viewControllerAtIndex(0, storyboard: self.storyboard!)!
let viewControllers = [startingViewController]
self.pageViewController!.setViewControllers(viewControllers, direction: .Forward, animated: true, completion: {done in })
self.pageViewController!.dataSource = self.modelController
self.addChildViewController(self.pageViewController!)
self.view.addSubview(self.pageViewController!.view)
// Set the page view controller's bounds using an inset rect so that self's view is visible around the edges of the pages.
var pageViewRect = self.view.bounds
if UIDevice.currentDevice().userInterfaceIdiom == .Pad {
pageViewRect = CGRectInset(pageViewRect, 0.0, 0.0)
}
self.pageViewController!.view.frame = pageViewRect
self.pageViewController!.didMoveToParentViewController(self)
/*
// Add the page view controller's gesture recognizers to the book view controller's view so that the gestures are started more easily.
self.view.gestureRecognizers = self.pageViewController!.gestureRecognizers
*/
self.view.gestureRecognizers = self.pageViewController?.gestureRecognizers
let pinchRecognizer = UIPinchGestureRecognizer(target: self, action: "pinchDetected:")
self.view.addGestureRecognizer(pinchRecognizer)
let panRecognizer = UIPanGestureRecognizer(target: self, action: "handlePan:")
panRecognizer.minimumNumberOfTouches = 2
panRecognizer.maximumNumberOfTouches = 2
self.view.addGestureRecognizer(panRecognizer)
}
func pinchDetected(pinchRecognizer: UIPinchGestureRecognizer) {
if (UIGestureRecognizerState.Began == pinchRecognizer.state) || (UIGestureRecognizerState.Changed == pinchRecognizer.state) {
// Use the x or y scale, they should be the same for typical zooming (non-skewing)
let curScale = pinchRecognizer.view!.layer.valueForKeyPath("transform.scale.x")!.floatValue
let currentScale = CGFloat(curScale!)
// Variables to adjust the max/min values of zoom
let minScale: CGFloat = 1.0;
let maxScale: CGFloat = 2.0;
let zoomSpeed: CGFloat = 0.5;
var deltaScale: CGFloat = pinchRecognizer.scale
// You need to translate the zoom to 0 (origin) so that you
// can multiply a speed factor and then translate back to "zoomSpace" around 1
deltaScale = ((deltaScale - 1) * zoomSpeed) + 1
// Limit to min/max size (i.e maxScale = 2, current scale = 2, 2/2 = 1.0)
// A deltaScale is ~0.99 for decreasing or ~1.01 for increasing
// A deltaScale of 1.0 will maintain the zoom size
deltaScale = min(deltaScale, maxScale / currentScale)
deltaScale = max(deltaScale, minScale / currentScale)
zoomTransform = CGAffineTransformScale(pinchRecognizer.view!.transform, deltaScale, deltaScale);
pinchRecognizer.view!.transform = zoomTransform!;
// Reset to 1 for scale delta's
// Note: not 0, or we won't see a size: 0 * width = 0
pinchRecognizer.scale = 1;
}
}
func handlePan(recognizer:UIPanGestureRecognizer) {
let translation = recognizer.translationInView(self.view)
if let view = recognizer.view {
view.center = CGPoint(x:view.center.x + translation.x,
y:view.center.y + translation.y)
}
recognizer.setTranslation(CGPointZero, inView: self.view)
if recognizer.state == UIGestureRecognizerState.Ended {
// 1
let velocity = recognizer.velocityInView(self.view)
let magnitude = sqrt((velocity.x * velocity.x) + (velocity.y * velocity.y))
let slideMultiplier = magnitude / 200
// print("magnitude: \(magnitude), slideMultiplier: \(slideMultiplier)")
// 2
let slideFactor = 0.1 * slideMultiplier //Increase for more of a slide
// 3
var finalPoint = CGPoint(x:recognizer.view!.center.x + (velocity.x * slideFactor),
y:recognizer.view!.center.y + (velocity.y * slideFactor))
// 4
finalPoint.x = min(max(finalPoint.x, 0), self.view.bounds.size.width)
finalPoint.y = min(max(finalPoint.y, 0), self.view.bounds.size.height)
// 5
UIView.animateWithDuration(Double(slideFactor),
delay: 0,
// 6
options: UIViewAnimationOptions.CurveEaseOut,
animations: {recognizer.view!.center = finalPoint },
completion: nil)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
var modelController: CatalougeViewControllerModel {
// Return the model controller object, creating it if necessary.
// In more complex implementations, the model controller may be passed to the view controller.
if _modelController == nil {
_modelController = CatalougeViewControllerModel()
}
return _modelController!
}
var _modelController: CatalougeViewControllerModel? = nil
// MARK: - UIPageViewController delegate methods
func pageViewController(pageViewController: UIPageViewController, spineLocationForInterfaceOrientation orientation: UIInterfaceOrientation) -> UIPageViewControllerSpineLocation {
if (orientation == .Portrait) || (orientation == .PortraitUpsideDown) || (UIDevice.currentDevice().userInterfaceIdiom == .Phone) {
// In portrait orientation or on iPhone: Set the spine position to "min" and the page view controller's view controllers array to contain just one view controller. Setting the spine position to 'UIPageViewControllerSpineLocationMid' in landscape orientation sets the doubleSided property to true, so set it to false here.
let currentViewController = self.pageViewController!.viewControllers![0]
let viewControllers = [currentViewController]
self.pageViewController!.setViewControllers(viewControllers, direction: .Forward, animated: true, completion: {done in })
self.pageViewController!.doubleSided = false
return .Min
}
// In landscape orientation: Set set the spine location to "mid" and the page view controller's view controllers array to contain two view controllers. If the current page is even, set it to contain the current and next view controllers; if it is odd, set the array to contain the previous and current view controllers.
let currentViewController = self.pageViewController!.viewControllers![0] as! DataViewController
var viewControllers: [UIViewController]
let indexOfCurrentViewController = self.modelController.indexOfViewController(currentViewController)
if (indexOfCurrentViewController == 0) || (indexOfCurrentViewController % 2 == 0) {
let nextViewController = self.modelController.pageViewController(self.pageViewController!, viewControllerAfterViewController: currentViewController)
viewControllers = [currentViewController, nextViewController!]
} else {
let previousViewController = self.modelController.pageViewController(self.pageViewController!, viewControllerBeforeViewController: currentViewController)
viewControllers = [previousViewController!, currentViewController]
}
self.pageViewController!.setViewControllers(viewControllers, direction: .Forward, animated: true, completion: {done in })
return .Mid
}
}
Thats the ViewControllerModel (CatalougeViewControllerModel):
class CatalougeViewControllerModel: NSObject, UIPageViewControllerDataSource {
override init() {
super.init()
}
func viewControllerAtIndex(index: Int, storyboard: UIStoryboard) -> DataViewController? {
// Return the data view controller for the given index.
if (PDF3.imagePath.count == 0) || (index >= PDF3.imagePath.count) {
return nil
}
// Create a new view controller and pass suitable data.
let dataViewController = storyboard.instantiateViewControllerWithIdentifier("DataViewController") as! DataViewController
dataViewController.dataObject = PDF3.imagePath[index]
return dataViewController
}
func indexOfViewController(viewController: DataViewController) -> Int {
// Return the index of the given data view controller.
// For simplicity, this implementation uses a static array of model objects and the view controller stores the model object; you can therefore use the model object to identify the index.
return PDF3.imagePath.indexOf(viewController.dataObject!) ?? NSNotFound
}
// MARK: - Page View Controller Data Source Seiten werden hochgezählt
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
var index = self.indexOfViewController(viewController as! DataViewController)
if (index == 0) || (index == NSNotFound) {
return nil
}
index--
return self.viewControllerAtIndex(index, storyboard: viewController.storyboard!)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
var index = self.indexOfViewController(viewController as! DataViewController)
if index == NSNotFound {
return nil
}
index++
if index == PDF3.imagePath.count {
return nil
}
return self.viewControllerAtIndex(index, storyboard: viewController.storyboard!)
}
}
Thank you for your time to help me...

Answer 1

There exists a method on iOS that gets called whenever a device's memory gets constrained. By default, only the UIApplicationDelegate's gets called, but you can use NSNotificationCenter to add any class and/or object so they also get called.
When the method is called, it's a signal for your app to free some memory. You can then purge data that you don't need anymore.

Answer 2

I fixed my problem. So sorry guys the solution was in the DataViewController and I doesn´t posted my DataViewController file so anyway.
Here is my solution:
old DataViewController:
import UIKit
class DataViewController: UIViewController {
#IBOutlet weak var myImageView: UIImageView!
var dataObject: String?
override func viewDidLoad() {
super.viewDidLoad()
self.myImageView.image = UIImage(named: dataObject!)
// my Images was cached because I used "named:"
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Thats the new DataViewController:
import UIKit
class DataViewController: UIViewController {
#IBOutlet weak var myImageView: UIImageView!
var dataObject: String?
override func viewDidLoad() {
super.viewDidLoad()
autoreleasepool { () -> () in
self.myImageView.image = UIImage(contentsOfFile: dataObject!) // with "contentsOfFile:" the images are uncached...
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}