github地址：GKCoverSwift
使用方法：
// 1.创建要显示的视图，并设置大小
let topImage = UIImage(named: "top1")
let imageView = UIImageView(image: topImage)
imageView.gk_size = CGSize(width: kScreenW, height: kScreenW * (topImage?.size.height)! / (topImage?.size.width)!)
let v = UIView()
v.frame = CGRect(x: 0, y: 64, width: kScreenW, height: kScreenH - 64)
v.backgroundColor = UIColor.clear
view.addSubview(v)
// 2. 创建遮罩，并设置显示方式
let cover = GKCover(fromView: v, contentView: imageView, style: .Translucent, showStyle: .Top, showAnimStyle: .Top, hideAnimStyle: .Top, notClick: false, showBlock: {
}) {
v .removeFromSuperview()
}
// 3. 显示
cover.show()
具体demo详见github里面的demo。
第一次写swift，希望多多支持！
