所以我正在处理一个简单的UICollectionView,X行有3列,其中X由变量matchesFromSelectedSession.count + 1设置。以下是我用于collectionView的委托函数:
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
let cellHeight = 15.0 as CGFloat
return CGSizeMake(collectionView.bounds.size.width/3, cellHeight)
}
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return matchesFromSelectedSession.count + 1
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let reuseIdentifier = "MatchCollectionViewCell"
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! MatchCollectionViewCell
cell.matchCollectionLabel = UILabel(frame: CGRectMake(0,0,collectionView.bounds.width/3 - 3.0,15))
cell.matchCollectionLabel.textColor = UIColor.blackColor()
cell.systemLayoutSizeFittingSize(cell.frame.size, withHorizontalFittingPriority: UILayoutPriorityDefaultHigh, verticalFittingPriority: UILayoutPriorityDefaultLow)
cell.matchCollectionLabel.font = UIFont(name: "Helvetica Neue", size:12)
if indexPath.section == 0 {
switch indexPath.row {
case 0:
cell.matchCollectionLabel.text = "Match #"
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
cell.matchCollectionLabel.textAlignment = NSTextAlignment.Right
break
case 1:
cell.matchCollectionLabel.text = "Record"
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
cell.matchCollectionLabel.textAlignment = NSTextAlignment.Center
break
case 2:
cell.matchCollectionLabel.text = "Outcome"
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
break
default:
cell.matchCollectionLabel.text = ""
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
break
}
} else {
switch indexPath.row {
case 0:
cell.matchCollectionLabel.text = "\(indexPath.section)"
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
cell.matchCollectionLabel.textAlignment = NSTextAlignment.Right
break
case 1:
cell.matchCollectionLabel.text = matchesFromSelectedSession[indexPath.section - 1].matchRecord()
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
cell.matchCollectionLabel.textAlignment = NSTextAlignment.Center
break
case 2:
let outcome = matchesFromSelectedSession[indexPath.section - 1].matchOutcome()
switch outcome {
case "W":
cell.matchCollectionLabel.text = "Win"
cell.matchCollectionLabel.textColor = UIColor.greenColor()
break
case "D":
cell.matchCollectionLabel.text = "Draw"
cell.matchCollectionLabel.textColor = UIColor.blueColor()
break
case "L":
cell.matchCollectionLabel.text = "Loss"
cell.matchCollectionLabel.textColor = UIColor.redColor()
break
default:
cell.matchCollectionLabel.textColor = UIColor.blackColor()
break
}
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
break
default:
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
cell.matchCollectionLabel.text = ""
break
}
}
//add subview if new cell otherwise tag cell to know to reuse next time
if cell.tag != 19 {
cell.addSubview(cell.matchCollectionLabel)
}
cell.tag = 19
return cell
}
我使用的自定义单元格MatchCollectionViewCell只包含一个标签matchCollectionLabel,就是这样。我在视图的viewDidAppear函数中使用self.matchCollectionView.reloadData(),以便在辅助视图更改表并关闭回原始视图时。
我在第一次使用后标记了单元格,在每次viewDidAppear之后,我都不会不断地向单元格添加不必要的子视图。
在初始设置之后,该表看起来很棒,但在调用reloadData之后,collectionView的单元格顺序会发生变化并混乱。如果我编辑单元格数,则reloadData()更新以正确显示单元格编号更改但单元格仍然处于错误的顺序。
这是reloadData之前和之后的图片
任何帮助将不胜感激!谢谢!
答案 0 :(得分:1)
您每次都在创建新标签。如果标签不是19,则只将其添加为子视图,但始终分配新标签。
这意味着当您重复使用单元格时,您正在更新新标签,而不是已添加到单元格中的标签,因此您的更改不可见。
您可以将标记检查移动到函数顶部,并使用它来控制标签的分配,或将matchCollectionLabel
定义为可选项,然后您可以检查nil
:
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let reuseIdentifier = "MatchCollectionViewCell"
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! MatchCollectionViewCell
if cell.matchCollectionLabel == nil {
cell.matchCollectionLabel = UILabel(frame: CGRectMake(0,0,collectionView.bounds.width/3 - 3.0,15))
cell.matchCollectionLabel!.textColor = UIColor.blackColor()
cell.systemLayoutSizeFittingSize(cell.frame.size, withHorizontalFittingPriority: UILayoutPriorityDefaultHigh, verticalFittingPriority: UILayoutPriorityDefaultLow)
cell.matchCollectionLabel!.font = UIFont(name: "Helvetica Neue", size:12)
cell.addSubview(cell.matchCollectionLabel!)
}
if indexPath.section == 0 {
switch indexPath.row {
case 0:
cell.matchCollectionLabel!.text = "Match #"
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
cell.matchCollectionLabel!.textAlignment = NSTextAlignment.Right
break
case 1:
cell.matchCollectionLabel!.text = "Record"
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
cell.matchCollectionLabel!.textAlignment = NSTextAlignment.Center
break
case 2:
cell.matchCollectionLabel!.text = "Outcome"
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
break
default:
cell.matchCollectionLabel!.text = ""
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
break
}
} else {
switch indexPath.row {
case 0:
cell.matchCollectionLabel!.text = "\(indexPath.section)"
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
cell.matchCollectionLabel!.textAlignment = NSTextAlignment.Right
break
case 1:
cell.matchCollectionLabel!.text = matchesFromSelectedSession[indexPath.section - 1].matchRecord()
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
cell.matchCollectionLabel!.textAlignment = NSTextAlignment.Center
break
case 2:
let outcome = matchesFromSelectedSession[indexPath.section - 1].matchOutcome()
switch outcome {
case "W":
cell.matchCollectionLabel!.text = "Win"
cell.matchCollectionLabel!.textColor = UIColor.greenColor()
break
case "D":
cell.matchCollectionLabel!.text = "Draw"
cell.matchCollectionLabel!.textColor = UIColor.blueColor()
break
case "L":
cell.matchCollectionLabel!.text = "Loss"
cell.matchCollectionLabel!.textColor = UIColor.redColor()
break
default:
cell.matchCollectionLabel!.textColor = UIColor.blackColor()
break
}
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
break
default:
if indexPath.section%2 == 0 {
cell.backgroundColor = ImageEditor.colorWithHexString("EFEFF4")
}
cell.matchCollectionLabel!.text = ""
break
}
}
return cell
}