ios - UITableView 卡住单元格。如何解决？

Question

我有 tableView cellForRowAtIndexPath 功能:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
  let cell: ProjectCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! ProjectCell
  let rightUtilityButtons = NSMutableArray()
  rightUtilityButtons.sw_addUtilityButtonWithColor(UIColor(red: 255.0/255.0, green: 200.0/255.0, blue: 122.0/255.0, alpha: 1.0), icon: UIImage(named: "ic_edit"))
  rightUtilityButtons.sw_addUtilityButtonWithColor(UIColor(red: 255.0/255.0, green: 120.0/255.0, blue: 122.0/255.0, alpha: 1.0), icon: UIImage(named: "ic_close"))
  cell.setRightUtilityButtons(rightUtilityButtons as [AnyObject], withButtonWidth: 70)
  cell.delegate = self

  let project = projects[indexPath.row] as! Project
  cell.projectNameLabel.text = project.name
  cell.projectDescriptionLabel.text = project.desc
  cell.projectDateLabel.text = project.duedate 

  cell.customView.backgroundColor = getColor(indexPath.row * 10)
  cell.backView.layer.cornerRadius = 6
  cell.backView.layer.shadowColor = UIColor.blackColor().CGColor
  cell.backView.layer.shadowOffset = CGSize(width: -1, height: 1)
  cell.backView.layer.shadowOpacity = 0.5   

  return cell
}

问题在这里:

cell.backView.layer.shadowColor = UIColor.blackColor().CGColor
cell.backView.layer.shadowOffset = CGSize(width: -1, height: 1)
cell.backView.layer.shadowOpacity = 0.5

如果没有这段代码，我的 TableView 会很好用。如何解决这个问题呢。也许我的单元格 View 更好的地方是 willDisplayCell，但是如何将这段代码放在那里？

Answer 1

1. 将设置阴影的代码移动到单元格的初始化。现在，每次委托(delegate)将单元格返回到 TableView 时都会设置阴影。对于刚刚被重复使用并且已经配置了阴影的单元格，您不必执行此操作。

2. 记得在处理阴影时设置shadowPath。它提高了性能。

   [view.layer setShadowPath:[[UIBezierPath  bezierPathWithRect:view.bounds] CGPath]];