UICollectionView滚动/滑动到下一个项目

Question

I have a UICollectionView in a view controller. When the user clicks one of the images, it goes to a separate page to open the image. I would like instead of going back to the gallery each time to change pictures, to swipe left or right to get the next or previous picture.

I have seen answers to do "pagingEnabled = true" but where do you put this exactly?

I am new to swift.

Below is my code. Thanks for the help in advance.

ViewController.swift

import UIKit

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate
{
@IBOutlet weak var collectionView: UICollectionView!

let appleProducts = ["iPhone", "Apple Watch", "Mac", "iPad"]
let imageArray = [UIImage(named: "pug"), UIImage(named: "pug2"), UIImage(named: "pug3"), UIImage(named: "pug4")]

override func viewDidLoad()
{
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

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

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
    return self.appleProducts.count
}

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

    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! CollectionViewCell

    cell.imageView?.image = self.imageArray[indexPath.row]

    cell.titleLabel?.text = self.appleProducts[indexPath.row]

    return cell

}

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath)
{
    self.performSegueWithIdentifier("showImage", sender: self)
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
    if segue.identifier == "showImage"
    {
        let indexPaths = self.collectionView!.indexPathsForSelectedItems()!
        let indexPath = indexPaths[0] as NSIndexPath
        let vc = segue.destinationViewController as! NewViewController
        vc.image = self.imageArray[indexPath.row]!
        vc.title = self.appleProducts[indexPath.row]
    }
}

}

CollectionViewCell.swift

import UIKit

class CollectionViewCell: UICollectionViewCell
{
@IBOutlet weak var imageView: UIImageView!
@IBOutlet weak var titleLabel: UILabel!
}

NewViewController.swift

import UIKit

class NewViewController: UIViewController
{
@IBOutlet weak var imageView: UIImageView!
var image = UIImage()

override func viewDidLoad()
{
    super.viewDidLoad()

    self.imageView.image = self.image
}

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


/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
}
*/

}

Answer 1

In the view controller that is presented after a tap, you should make a horizontally scrolling UICollectionView . On this collection view, set its pagingEnabled property to true.

The next thing to do is reformat your prepareForSegue method in your parent view controller to pass the entire array of images to the presented view controller as well as the selected index path.

Then, in your presented view controller, you should have the collection view's data source be configured to show all the images but make sure to start at the initial, selected index path that was passed by the parent view controller.