在初始加载时删除UITableViewCell的右侧阴影

我正在尝试创建卡片类型的布局，并在这里使用了许多答案以获取当前的解决方案。我正在使用Swift 2和XCode 7.3.1。

首次应用加载

拉后刷新

UITableViewCell代码为：

func addShadow() {
  cardView.layer.shadowPath = UIBezierPath(rect: cardView.bounds).CGPath
  cardView.layer.shadowOpacity = 0.7
  cardView.layer.shadowOffset = CGSizeZero
  cardView.layer.shadowRadius = 2
  cardView.layer.masksToBounds = false
}

override func layoutSubviews() {
  addShadow()
}

为什么单元格仅在拉动刷新后才看起来正确，并且事先在右侧有多余的阴影？

编辑：

我也添加了TableViewController

class BusinessTableViewController: PFQueryTableViewController {

  override func viewDidLoad() {
    super.viewDidLoad()
    navigationController!.navigationBar.translucent = false
    navigationController?.toolbar.translucent = false
    configureTable()
    // Do any additional setup after loading the view.
  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }

  func configureTable() {
    tableView.tableFooterView = UIView(frame: CGRectZero)
    tableView.backgroundColor = Utility.tableBackgroundColor
  }

  override func queryForTable() -> PFQuery {
    let query = PFQuery(className: "Business")
    query.cachePolicy = .NetworkElseCache
    query.orderByAscending("createdAt")
    return query
  }

  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath, object: PFObject?) -> PFTableViewCell? {
    let cell = tableView.dequeueReusableCellWithIdentifier("businessCell", forIndexPath: indexPath) as! BusinessCell
    cell.layoutIfNeeded()

    let business = object as! Business
    cell.nameLabel.text = business.name
    var categoryString = ""

    for cat in business.categories {
      categoryString += cat

      if cat != business.categories.last {
        categoryString += ", "
      }
    }

    // Image setup
    if cell.mainImageView.layer.cornerRadius != 3 {
      cell.mainImageView.layer.cornerRadius = 3
      cell.mainImageView.clipsToBounds = true
      cell.mainImageView.layer.frame = CGRectInset(cell.mainImageView.layer.frame, 60, 60)
      cell.mainImageView.layer.borderColor = UIColor.purpleColor().CGColor
      cell.mainImageView.layer.borderWidth = 2.0
    }
    let imageFile = business.displayImage
    cell.mainImageView.file = imageFile
    cell.mainImageView.loadInBackground()

    // Button steup
    let defaultAttributes = [
      NSFontAttributeName: UIFont.fontAwesomeOfSize(15),
      NSForegroundColorAttributeName: UIColor.grayColor()]
    let activeAttributes = [
      NSFontAttributeName: UIFont.fontAwesomeOfSize(15),
      NSForegroundColorAttributeName: UIColor.blueColor()]

    cell.bookmarkButton.setTitleTextAttributes(defaultAttributes, forState: .Normal)
    cell.bookmarkButton.title = "\(String.fontAwesomeIconWithName(.BookmarkO)) Bookmark"

    let bookmarkQuery = PFQuery(className: "Bookmark")
    bookmarkQuery.whereKey("business", equalTo: business)
    bookmarkQuery.whereKey("user", equalTo: User.currentUser()!)
    bookmarkQuery.cachePolicy = .NetworkElseCache
    bookmarkQuery.countObjectsInBackgroundWithBlock { (count, error) in
      if error == nil && count > 0 {
        cell.bookmarkButton.setTitleTextAttributes(activeAttributes, forState: .Normal)
        cell.bookmarkButton.title = "\(String.fontAwesomeIconWithName(.Bookmark)) Bookmark"
      }
    }

    cell.phoneButton.setTitleTextAttributes(defaultAttributes, forState: .Normal)
    cell.phoneButton.title = "\(String.fontAwesomeIconWithName(.Phone)) Call"
    if business.phone == "" {
      cell.phoneButton.enabled = false
    }
    cell.reviewButton.setTitleTextAttributes(defaultAttributes, forState: .Normal)
    cell.reviewButton.title = "\(String.fontAwesomeIconWithName(.MapMarker)) Directions"

    return cell
  }

  override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    if indexPath.row + 1 > self.objects?.count {
      return 44
    }

    let height = super.tableView(tableView, heightForRowAtIndexPath: indexPath)
    return height
  }

  override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    if indexPath.row >= self.objects?.count {
      self.loadNextPage()
      tableView.deselectRowAtIndexPath(indexPath, animated: true)
      return
    }

    //performSegueWithIdentifier("viewBusiness", sender: self)
  }

  /*
   // MARK: - Navigation

   // In a storyboard-based application, you will often want to do a little preparation before navigation
   override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
   // Get the new view controller using segue.destinationViewController.
   // Pass the selected object to the new view controller.
   }
   */

}