在可展开的集合视图单元格

Question

我有一个包含两个单元格的集合视图。我通过select（didSelectItemAtIndexPath）使单元格展开/折叠。单元格包含其他视图，这些视图应在展开模式下可见并在折叠中隐藏。如果我使用扩展单元格，我的代码可以正常工作，但如果我已经扩展单元格并点击折叠，则展开的单元格会更改其大小，但其他视图仍然可见。也许在gif上看起来很容易理解。 好的方案：

1. 点击第一个单元格=展开
2. 再次点击第一个单元格=折叠它并隐藏图片视图

行李场景：

1. 点击第一个单元格=展开
2. 点击第二个单元格=展开第二个单元格＆amp;折叠第一个单元格但第一个单元格上的其他图像视图仍然可见
3. 再次点击第二个单元格=折叠第二个单元格并隐藏其内容。第一个单元格上的附加图像视图仍然可见



以下是cell代码：

class ExerciseSetCell: BaseCell {

// timer
let timerButton: UIButton = {
    let button = UIButton()
    button.setImage(UIImage(named: "timer"), forState: .Normal)
    button.frame = CGRectMake(0, 0, 25, 25)
    button.alpha = 0
    return button
}()

override func setupViews() {
    super.setupViews()

    backgroundColor = UIColor.whiteColor()

    addSubview(timerButton)
    timerButton.snp_makeConstraints { (make) in
        make.width.equalTo(25)
        make.height.equalTo(25)
        make.bottomMargin.equalTo(-7)
        make.centerX.equalTo(self)
    }
}

}

这是我的collectionViewController代码：

class ExerciseDetailVC: UICollectionViewController, UICollectionViewDelegateFlowLayout {

var exercise: Exercise?
let exerciseSetCell = ExerciseSetCell()
private let setCell = "ExerciseSetCell"
private var expandedCellIndex = -1

override func viewDidLoad() {
    super.viewDidLoad()

    collectionView?.registerClass(ExerciseSetCell.self, forCellWithReuseIdentifier: setCell)
}

override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 2
}

override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier(setCell, forIndexPath: indexPath) as! ExerciseSetCell
    return cell
}

override func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    let cell = collectionView.cellForItemAtIndexPath(indexPath) as! ExerciseSetCell

    if expandedCellIndex == indexPath.item {

        UIView.animateWithDuration(0.1, animations: {
            cell.weightView.alpha = 0
            cell.timerButton.alpha = 0
        })
        expandedCellIndex = -1

    } else {

        UIView.animateWithDuration(0.25, animations: {
            cell.weightView.alpha = 1
            cell.timerButton.alpha = 1
        })

        expandedCellIndex = indexPath.item
    }
    collectionView.reloadData()
}

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    if expandedCellIndex == indexPath.item {
        return CGSizeMake(view.frame.width, 200)
    }
    return CGSizeMake(view.frame.width, 60)

}

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
    return 2
}