UICollectionView单元格视图重叠

Question

我有像这样重叠的单元格：

我cellForItemAtIndexPath是这样的：

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as UICollectionViewCell

cell.backgroundColor = UIColor(red: 27.0/255.0, green: 38.0/255.0, blue: 52.0/255.0, alpha: 1.0)
let textFrame = CGRect(x: 0, y: cell.frame.height * 0.30, width: cell.frame.width, height: cell.frame.height)
var textLabel: UILabel! = UILabel(frame: textFrame)
textLabel.font = UIFont(name:"Helvetica-Light", size: 14.0)
textLabel.textAlignment = .Center
textLabel.textColor = UIColor.whiteColor()

println(categoryArray[indexPath.row].category)

textLabel.text = categoryArray[indexPath.row].category
var cellImage = UIImage(named: categoryArray[indexPath.row].catImage)//Array(Array(model.categories.values)[cellCount])[1]

let imageSize = cell.frame.height * 0.45

let imageView = UIImageView(image: cellImage as UIImage?)
imageView.frame = CGRect(x: (cell.frame.width / 2) - (imageSize / 2), y:cell.frame.height * 0.15, width: imageSize, height: imageSize)

var bottomBorder: UIView = UIView(frame:CGRectMake(0, cell.frame.height - 1.0, cell.frame.width, 5));
//bottomBorder.backgroundColor = UIColor(rgba: Array(Array(model.categories.values)[cellCount])[0] as String)
bottomBorder.backgroundColor = UIColor(rgba: "#A64259")

cell.addSubview(imageView)
cell.addSubview(bottomBorder)
cell.addSubview(textLabel)

cellCount++
return cell
}

我知道它可以重用单元格，好主意...除了如何防止单元格文本重叠之外？

---

编辑-潜在解决方案＃1

由于这些子视图不断地被修改，所以我想，如果我只是转储它们并创建新的子视图，该怎么办，我使用了：

for view in cell.subviews {
  view.removeFromSuperview()
}

这似乎可以解决问题。我怀疑这比修改子视图中特定元素的值要多一些开销。将进一步调查。

Answer 1

发生这种情况的原因是因为单元被重用，最终您将图像作为子视图多次添加到了同一UICollectionViewCell对象。您可以创建一个扩展UICollectionViewCell的自定义类，以便保留所添加的imageView。

class ImageCell : UICollectionViewCell {
    private(set) var imageView : UIImageView?
    private(set) var textLabel : UILabel?

    func setImage(image: UIImage?) {
        if self.imageView == nil {
            let imageSize = cell.frame.height * 0.45
            self.imageView = UIImageView()
            self.imageView.frame = CGRect(x: (self.frame.width / 2) - (imageSize / 2), y:self.frame.height * 0.15, width: imageSize, height: imageSize)
            self.addSubview(imageView!)
        }

        imageView!.image = image
    }

    func setLabel(text: String) {
        if self.textLabel == nil {
            let textFrame = CGRect(x: 0, y: self.frame.height * 0.30, width: self.frame.width, height: self.frame.height)
            self.textLabel = UILabel(frame: textFrame)
            textLabel.font = UIFont(name:"Helvetica-Light", size: 14.0)
            textLabel.textAlignment = .Center
            textLabel.textColor = UIColor.whiteColor()
        }

        textLabel.text = text
    }
}

然后在您的cellForItemAtIndexPath中：

let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as ImageCell

var cellImage =  UIImage(named: categoryArray[indexPath.row].catImage)
cell.setImage(cellImage)
cell.setLabel(categoryArray[indexPath.row].category)

显然，您必须对其进行自定义才能获得相同的布局，但这应该可以帮助您入门。