How to set position of cell of collectionview swift? - ios

Question

i am using collectionview to show image in full screen and allowing scrolling between different images. but when orientation will change it's not showing properly..And this is my code
override func willRotate(to toInterfaceOrientation: UIInterfaceOrientation, duration: TimeInterval) {
// collectionView.reloadData()
collectionView.collectionViewLayout.invalidateLayout()
if visibleCell != nil {
collectionView.selectItem(at: visibleCell as IndexPath?, animated: true, scrollPosition: .centeredHorizontally)
}
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return images.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ImageCell", for: indexPath) as! ImageCollectionViewCell
print(cell.frame)
cell.SectionImage.image = images[indexPath.row].image
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: self.view.frame.width, height: self.view.frame.height)
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0
}

Answer 1

Use UICollectionView sizeForItemAtIndexPath method to define height and width of cell.
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
let leftAndRightPaddings: CGFloat = 15.0
let numberOfItemsPerRow: CGFloat = CGFloat(NUMBER_OF_ITEMS_PER_ROW)
let bounds = UIScreen.mainScreen().bounds
let width = (bounds.size.width - leftAndRightPaddings * (numberOfItemsPerRow+1)) / numberOfItemsPerRow
let layout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
layout.itemSize = CGSizeMake(width, width)
return layout.itemSize
}
Try it. And you will get your expected result.

Answer 2

First of all set the minimum spacing for cell and lines to 0.
After that return the size of cell equal to UICollectionView by using the delegate method
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize{
return CGSizeMake(collectionView.frame.size.width, collectionView.frame.size.height)
}
override func willRotateToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
dispatch_async(dispatch_get_main_queue()) {
self.collectionView.reloadData()
}
print_debug("change orientation")
}
Its work for me in the same situation.