Question

我以编程方式创建Collection视图。这是viewDidLoad func中的代码

let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
    layout.sectionInset = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
    layout.itemSize = CGSize(width: 90, height: 120)
    collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
    collectionView!.dataSource = self
    collectionView!.delegate = self
    collectionView!.registerClass(CollectionViewCell.self, forCellWithReuseIdentifier: "CollectionViewCell")
    collectionView!.layer.cornerRadius = 2
    collectionView!.backgroundColor = UIColor.redColor()
    self.containerView.addSubview(collectionView!)

这些是我的集合视图函数

func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
    return 1
}

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 8
}

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CollectionViewCell", forIndexPath: indexPath) as! CollectionViewCell
    cell.backgroundColor = UIColor.blackColor()
    cell.buttonView.addTarget(self, action: Selector("Action\(indexPath.row):"), forControlEvents: UIControlEvents.TouchUpInside)
    return cell
}

想法是我在单元格中有一个按钮，当我按下它时，单元格应该改变颜色，这里是动作功能

func Action0(sender: UIButton!) {
    var indexPath = NSIndexPath(forRow: 0, inSection: 0)
    let cell = collectionView!.dequeueReusableCellWithReuseIdentifier("CollectionViewCell", forIndexPath: indexPath ) as! CollectionViewCell
    cell.backgroundColor = UIColor.blueColor()

这是collectionViewCell类，

class CollectionViewCell: UICollectionViewCell {

required init(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

var buttonView: UIButton!
override init(frame: CGRect) {
    super.init(frame: frame)

    buttonView = UIButton.buttonWithType(UIButtonType.System) as! UIButton
    buttonView.frame = CGRect(x: 0, y: 16, width: frame.size.width, height: frame.size.height*2/3)

    contentView.addSubview(buttonView)
}

}

按钮和动作有效但单元格不会改变颜色，我猜问题就在这一行

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

Answer 1

这是获取给定indexPath的单元格的方法：

let cell = collectionView!.cellForItemAtIndexPath(indexPath)

但是，您也可以尝试：

cell.contentView.backgroundColor = UIColor.blueColor()

注意：

虽然上面的内容可能有用，但我想鼓励您尝试不同的实现来实现相同的功能。您的实现将要求您为每个CollectionViewCell分别设置一个Action＃函数，并在每个方法中手动创建indexPath，而您可能只有一个！

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CollectionViewCell", forIndexPath: indexPath) as! CollectionViewCell
    cell.backgroundColor = UIColor.blackColor()
    cell.buttonView.addTarget(self, action: Selector("action"), forControlEvents: UIControlEvents.TouchUpInside)
    return cell
}

和那个方法的函数类似于：

func action(sender: UIButton!) {
    var point : CGPoint = sender.convertPoint(CGPointZero, toView:collectionView)
    var indexPath = collectionView!.indexPathForItemAtPoint(point)
    let cell = collectionView!.cellForItemAtIndexPath(indexPath)
    cell.backgroundColor = UIColor.blueColor()
}

更新了Swift 4.2的操作功能

@objc func action(sender: Any){
    print("tickedOffPressed !")
    if let button = sender as? UIButton {
        let point: CGPoint = button.convert(.zero, to: collectionView)
        if let indexPath = collectionView!.indexPathForItem(at: point) {
            let cell = collectionView!.cellForItem(at: indexPath)
            cell?.backgroundColor = UIColor.blue
        }
    }
}

只是一个建议！快乐的编码！：）

Answer 2

在Swift 4中，您可以使用以下内容获取CollectionView的单元格：

let indexPath = IndexPath(item: 3, section: 0);  
if let cell = myCollectionView .cellForItem(at: indexPath)  
{   
   // do stuff...  
}

Answer 3

尝试cell.selected，然后更改颜色

Answer 4

在Swift 2中，您可以获得以下行：

let point : CGPoint = sender.convertPoint(CGPointZero, toView:myTableView)
let indexPath = myTableView.indexPathForRowAtPoint(point)
let cell = myTableView.cellForRowAtIndexPath(indexPath!)

如何使用swift获取UICollectionView中的单元格atIndex？

4 个答案: