UICollectionView Horizontal Scrolling Photo Gallery with Fast

Question

I am trying to make a photo gallery using UICollectionViewwith Swift. I want to display photos in full screen and scroll right to go to the next image. I have a working code for the portrait frame, but as soon as I go into the landscape, it seems that my cell is not reconfiguring to the correct position and size.

This means that it always keeps the same width, height, x positionand y positionon the portrait screen. I also get this error in both portrait and landscape frames:

-> The behavior of the UICollectionViewFlowLayout is not defined because:

-> the height of the element must be less than the height of the UICollectionView minus the upper and lower values ​​of the sections.

I looked around the internet for the answer and tried all possible solutions, but it doesn't seem to work for me. Let me know if anyone can help with this. Very much appreciated.

Here is my code:

import UIKit

class ImageDetailViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout,UINavigationControllerDelegate {


@IBOutlet weak var imgDetailCollectionView: UICollectionView!

var index: Int!
var imageItems: Array<Items> = []
var currentIndex: CGFloat!
var size = UIScreen.mainScreen().bounds.size
init(index: Int , imageItems: Array<Items>) {
    self.index = index
    self.imageItems = imageItems
    super.init(nibName: "ImageDetailViewController", bundle: NSBundle.mainBundle())
}

required init(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

override func viewDidLoad() {
    super.viewDidLoad()


    imgDetailCollectionView.registerNib(UINib(nibName: "ImageDetailCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ImageDetailCollectionViewCell")
    //self.automaticallyAdjustsScrollViewInsets = false
    imgDetailCollectionView.setZoomScale(0.5, animated: true)

}




override func viewDidLayoutSubviews() {
    imgDetailCollectionView.scrollRectToVisible(CGRectMake(320 * CGFloat(index), 0, 320 , 240), animated: false)
}



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

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int{

    return self.imageItems.count
}


func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell{






    var cell = imgDetailCollectionView.dequeueReusableCellWithReuseIdentifier("ImageDetailCollectionViewCell", forIndexPath: indexPath) as ImageDetailCollectionViewCell

    cell.setup(imageItems[indexPath.row].url!)

    if(UIDeviceOrientationIsPortrait(UIDevice.currentDevice().orientation)){


        self.imgDetailCollectionView.collectionViewLayout.invalidateLayout()

        var frame = cell.frame
        frame.size = CGSizeMake(size.width, size.height)
        cell.frame = frame

    }else{
        self.imgDetailCollectionView.collectionViewLayout.invalidateLayout()

        var frame = cell.frame
        frame.size = CGSizeMake(size.height, size.width)
        cell.frame = frame
    }

    return cell

}


func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

    var size = UIScreen.mainScreen().bounds.size

    if(UIDeviceOrientationIsPortrait(UIDevice.currentDevice().orientation)){


        return CGSizeMake(size.width, size.height)


    }else{

        return CGSizeMake(size.height, size.width)
    }



}

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
    return 0
}

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAtIndex section: Int) -> CGFloat {
    return 0
}


override func willRotateToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
    self.imgDetailCollectionView.collectionViewLayout.invalidateLayout()

    var currentOffset = self.imgDetailCollectionView.contentOffset
    self.currentIndex = currentOffset.x / imgDetailCollectionView.frame.size.width

}


override func didRotateFromInterfaceOrientation(fromInterfaceOrientation: UIInterfaceOrientation) {

    var currentSize = imgDetailCollectionView.bounds.size
    var offset = self.currentIndex * currentSize.width
    imgDetailCollectionView.setContentOffset(CGPointMake(offset, 0), animated: false)

    imgDetailCollectionView.reloadData()
}

override func willAnimateRotationToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {

    self.imgDetailCollectionView.collectionViewLayout.invalidateLayout()
}
}

Answer 1

Your problem is that you check the orientation and use the height for the width when it is in landscape mode. This is not true. When the device is rotated, the width property will return the actual height of the device when it was in the portrait.

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    var cell = imgDetailCollectionView.dequeueReusableCellWithReuseIdentifier("ImageDetailCollectionViewCell", forIndexPath: indexPath) as ImageDetailCollectionViewCell
    cell.setup(imageItems[indexPath.row].url!)
    cell.frame.size = view.frame.size
    return cell
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    return CGSizeMake(view.frame.width, view.frame.height)
}

: apple viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator), API. , iOS9, , .

Answer 2

- :

var size = UIScreen.mainScreen(). bounds.size

, :

var size = UIScreen.mainScreen(). bounds.size * 0.25

, collectionView contentInsets sectionInsets (collectionView.bounds.height).

, , "", Collection.