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CollectionViewが次のセルに自動的に移動するswift

私はフリップカートのような水平スライダーを作成しようとしています。水平スクロールとページングでcollectionViewを使用しています。セルにはimageViewが含まれています。アイテムを手動で水平にスクロールすることに成功しましたが、これらすべてのアイテムを自動と手動の両方で移動させたいです。 collectionViewのアイテムを自動的にスクロールする方法がわかりません。これを行うために私を案内してください。

私はviewDidAppearでこのコードを使用しています：

let visibleIndexPath: NSIndexPath = self.collectionView.indexPathForCell(cell)!

self.collectionView.scrollToItemAtIndexPath(visibleIndexPath,  
atScrollPosition: UICollectionViewScrollPosition.CenteredHorizontally, animated: true)

ありがとう。

編集：

import UIKit

class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {

    @IBOutlet var pageControl: UIPageControl!
    @IBOutlet var collectionView: UICollectionView!
    var begin = false
    let image1 = UIImage(named: "Slide 1")
    let image2 = UIImage(named: "Slide 2")
    let image3 = UIImage(named: "Slide 1")

    var images = [UIImage]()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        images = [image1!, image2!, image3!]
        startTimer()
    }        

    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        pageControl.numberOfPages = images.count
        return images.count
    }

    var cell : CollectionViewCell1!

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

      cell = collectionView.dequeueReusableCellWithReuseIdentifier("CollectionViewCell1", forIndexPath: indexPath) as! CollectionViewCell1
        cell.cell_image.image = images[indexPath.row]

        return cell
    }


    /**
     Scroll to Next Cell
     */
    func scrollToNextCell(){

        //get cell size
        let cellSize = CGSizeMake(self.view.frame.width, self.view.frame.height);

        //get current content Offset of the Collection view
        let contentOffset = collectionView.contentOffset;

            //scroll to next cell
        if begin == true
        {
            pageControl.currentPage == 0
            collectionView.scrollRectToVisible(CGRectZero, animated: true)
            begin = false
        }
        else
        {
            collectionView.scrollRectToVisible(CGRectMake(contentOffset.x + cellSize.width, contentOffset.y, cellSize.width, cellSize.height), animated: true);
        }

    }

    /**
     Invokes Timer to start Automatic Animation with repeat enabled
     */

    func startTimer() {

       NSTimer.scheduledTimerWithTimeInterval(2.0, target: self, selector: #selector(ViewController.scrollToNextCell), userInfo: nil, repeats: true);


    }

    func scrollViewDidEndDecelerating(scrollView: UIScrollView) {

        // If the scroll animation ended, update the page control to reflect the current page we are on

        pageControl.currentPage = Int((collectionView.contentOffset.x / collectionView.contentSize.width) * CGFloat(images.count))

        if collectionView.contentSize.width == collectionView.contentOffset.x + self.view.frame.width
        {
            begin = true

        }

    }

    func scrollViewDidEndScrollingAnimation(scrollView: UIScrollView) {

        // Called when manually setting contentOffset
        scrollViewDidEndDecelerating(scrollView)

    }

}

これは私のコード全体です。最後のセルの後に最初のセルに移動できません。私を助けてください。

swiftuicollectionviewpaginghorizontal-scrolling
9
Riddhi Shah

以下はあなたが試すことができるコードです：

    /**
     Scroll to Next Cell
     */
    func scrollToNextCell(){

        //get Collection View Instance
        let collectionView:UICollectionView;

        //get cell size
        let cellSize = CGSizeMake(self.view.frame.width, self.view.frame.height);

        //get current content Offset of the Collection view
        let contentOffset = collectionView.contentOffset;

        //scroll to next cell
        collectionView.scrollRectToVisible(CGRectMake(contentOffset.x + cellSize.width, contentOffset.y, cellSize.width, cellSize.height), animated: true);


    }

    /**
     Invokes Timer to start Automatic Animation with repeat enabled
     */
    func startTimer() {

        let timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("scrollToNextCell"), userInfo: nil, repeats: true);


    }
9
Babul Prabhakar

Swift4の場合

override func viewDidLoad() {
    super.viewDidLoad()

    startTimer()
}



func startTimer() {

    let timer =  Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.scrollAutomatically), userInfo: nil, repeats: true)
}


@objc func scrollAutomatically(_ timer1: Timer) {

    if let coll  = topMenuCollection {
        for cell in coll.visibleCells {
            let indexPath: IndexPath? = coll.indexPath(for: cell)
            if ((indexPath?.row)! < banner.count - 1){
                let indexPath1: IndexPath?
                indexPath1 = IndexPath.init(row: (indexPath?.row)! + 1, section: (indexPath?.section)!)

                coll.scrollToItem(at: indexPath1!, at: .right, animated: true)
            }
            else{
                let indexPath1: IndexPath?
                indexPath1 = IndexPath.init(row: 0, section: (indexPath?.section)!)
                coll.scrollToItem(at: indexPath1!, at: .left, animated: true)
            }

        }
    }
}

topMenuCollection：-コレクションビュー

banner.Count：-コレクションビューを含むセルの数

10
Sameer Saif

Swift

このテスト済みコードは次のセルにスクロールし、最後のセルの後にある最初のアイテムに戻ります。

     func setTimer() {
        let _ = Timer.scheduledTimer(timeInterval: 3.0, target: self, selector: #selector(MainVC.autoScroll), userInfo: nil, repeats: true)
    }

    var x = 1

    @objc func autoScroll() {
        if self.x < self.storiesForCollectionView.count {
        let indexPath = IndexPath(item: x, section: 0)
        self.collectionViewUp.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: true)
        self.x = self.x + 1
        } else {
            self.x = 0
            self.collectionViewUp.scrollToItem(at: IndexPath(item: 0, section: 0), at: .centeredHorizontally, animated: true)
        }
    }
override func viewDidLoad() {
        super.viewDidLoad()
        setTimer()
    }
8
Daniel Chernyshev
/**
 Scroll to Next Cell
 */
func scrollToNextCell(){

    //get cell size
    let cellSize = CGSizeMake(self.view.frame.width, self.view.frame.height);

    //get current content Offset of the Collection view
    let contentOffset = collectionView.contentOffset;

    if collectionView.contentSize.width <= collectionView.contentOffset.x + cellSize.width
    {
        collectionView.scrollRectToVisible(CGRectMake(0, contentOffset.y, cellSize.width, cellSize.height), animated: true);

    } else {
        collectionView.scrollRectToVisible(CGRectMake(contentOffset.x + cellSize.width, contentOffset.y, cellSize.width, cellSize.height), animated: true);

    }

}

/**
 Invokes Timer to start Automatic Animation with repeat enabled
 */
func startTimer() {
    NSTimer.scheduledTimerWithTimeInterval(2.0, target: self, selector: Selector("scrollToNextCell"), userInfo: nil, repeats: true);
}
7
Kamran

これが少し改善されたソリューションです。ユーザーが手動でスクロールを開始するとスクロールが停止し、セルが再び再利用されるとスクロールが再開されます。

var x = 0
weak var timer: Timer?

var cashbackOffers = [CashbackOffer]() {
    didSet {
        collectionView.reloadData()
        autoScroll()
    }
}

fileprivate func autoScroll() {
    x = 0
    timer?.invalidate()
    timer = Timer.scheduledTimer(withTimeInterval: 3.0, repeats: true) { [weak self] timer in
        guard let `self` = self else {
            timer.invalidate()
            return
        }
        if self.cashbackOffers.count == 0 {
            return
        }
        if self.x < self.cashbackOffers.count {
            let indexPath = IndexPath(item: self.x, section: 0)
            self.collectionView.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: true)
            self.x = self.x + 1
        } else {
            self.x = 1
            self.collectionView.scrollToItem(at: IndexPath(item: 0, section: 0), at: .centeredHorizontally, animated: true)
        }
    }
    timer?.fire()
}

func scrollViewDidScroll(_ scrollView: UIScrollView) {
    if scrollView.isTracking {
        timer?.invalidate()
    }
}

override func awakeFromNib() {
    super.awakeFromNib()
    autoScroll()
}
1
Ankit Srivastava

これを試して

var index = 0
var inForwardDirection = true
var timer: Timer?

@objc func scrollToNextCell() {

    //scroll to next cell
    let items = collectionViewTable.numberOfItems(inSection: 0)
    if (items - 1) == index {
        collectionViewTable.scrollToItem(at: IndexPath(row: index, section: 0), at: UICollectionViewScrollPosition.right, animated: true)
    } else if index == 0 {
        collectionViewTable.scrollToItem(at: IndexPath(row: index, section: 0), at: UICollectionViewScrollPosition.left, animated: true)
    } else {
        collectionViewTable.scrollToItem(at: IndexPath(row: index, section: 0), at: UICollectionViewScrollPosition.centeredHorizontally, animated: true)
    }

    if inForwardDirection {
        if index == (items - 1) {
            index -= 1
            inForwardDirection = false
        } else {
            index += 1
        }
    } else {
        if index == 0 {
            index += 1
            inForwardDirection = true
        } else {
            index -= 1
        }
    }

}

/**
 call this method when collection view loaded
 */
func startTimer() {
    if timer == nil {
        timer = Timer.scheduledTimer(timeInterval: 5.0, target: self, selector: #selector(scrollToNextCell), userInfo: nil, repeats: true);
    }
}
1
Moinuddin Girach

ScrollRectToVisibleではなく、コレクションビューメソッドscrollToItem(at:at:animated:)を使用することをお勧めします。これにより、どの長方形を公開するかを計算する必要がなくなります。スクロールするindexPathを指定するだけです。

1
Duncan C

スウィフト4：

func scrollToNextCell(){

    //get cell size
    let cellSize = view.frame.size

    //get current content Offset of the Collection view
    let contentOffset = collectionView.contentOffset

    if collectionView.contentSize.width <= collectionView.contentOffset.x + cellSize.width
    {
        let r = CGRect(x: 0, y: contentOffset.y, width: cellSize.width, height: cellSize.height)
        collectionView.scrollRectToVisible(r, animated: true)

    } else {
        let r = CGRect(x: contentOffset.x + cellSize.width, y: contentOffset.y, width: cellSize.width, height: cellSize.height)
        collectionView.scrollRectToVisible(r, animated: true);
    }

}
1
ingconti
 /**
 Scroll to Next Cell
 */
@objc func scrollToNextCell(){



    //get cell size
    let cellSize = CGSize(width:self.view.frame.size.width, height:viewForCV.frame.size.height)


    //get current content Offset of the Collection view
    let contentOffset = cvAdvertisements.contentOffset;

    if cvAdvertisements.contentSize.width <= cvAdvertisements.contentOffset.x + cellSize.width
    {
        cvAdvertisements.scrollRectToVisible(CGRect(x:0, y:contentOffset.y, width:cellSize.width, height:cellSize.height), animated: true);

    } else {

        cvAdvertisements.scrollRectToVisible(CGRect(x:contentOffset.x + cellSize.width, y:contentOffset.y, width:cellSize.width, height:cellSize.height), animated: true);

    }

}

/**
 Invokes Timer to start Automatic Animation with repeat enabled
 */
func startTimer() {

    Timer.scheduledTimer(timeInterval: 2.0, target: self, selector: #selector(LoginViewController.scrollToNextCell), userInfo: nil, repeats: true);

}
0
Davender Verma