用UIActivityIndicatorView类实现:
let activityView = UIActivityIndicatorView()
activityView.center = CGPoint(x: self.view.center.x, y: self.view.center.y-NavigationHeight)
// 停止后,隐藏菊花
activityView.hidesWhenStopped = true
//Style: whiteLarge比较大的白色环形进度条;white白色环形进度条;gray灰色环形进度条
activityView.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.whiteLarge
view.addSubview(self.activityView)
开启旋转动画:
activityView.startAnimating()
关闭旋转动画:
activityView.stopAnimating()