collectionviewcellselection.swift

override var isSelected: Bool{
  didSet{
    if self.isSelected
    {
      self.transform = CGAffineTransform(scaleX: 1.1, y: 1.1)
      self.contentView.backgroundColor = UIColor.red
      self.tickImageView.isHidden = false
    }
    else
    {
      self.transform = CGAffineTransform.identity
      self.contentView.backgroundColor = UIColor.gray
      self.tickImageView.isHidden = true
    }
  }
}