值

状态栏的高度 (self.navigationController?.navigationBar.frame.size.height)!
导航栏的高度 UIApplication.shared.statusBarFrame.size.height

常用方法

UIView.animate动画和snapkit的搭配使用，self.view.layoutIfNeeded()很关键。这里的view指的是进行动画的控件的直接父视图

#写法1:
UIView.animate(withDuration: 0.3) {
    self.promptSuggestOrdersView.snp.remakeConstraints { (make) in
         make.left.top.right.equalToSuperview()
         make.height.equalTo(40)
    }
    self.tableView.snp.remakeConstraints { (make) in
         make.top.equalTo(self.promptSuggestOrdersView.snp.bottom)
         make.left.right.equalToSuperview()
         make.bottom.equalTo(self.bottomBar.snp.top)
    }
    self.view.layoutIfNeeded()
 }
#写法2:
self.promptSuggestOrdersView.snp.remakeConstraints { (make) in
     make.left.top.right.equalToSuperview()
     make.height.equalTo(40)
}
self.tableView.snp.remakeConstraints { (make) in
     make.top.equalTo(self.promptSuggestOrdersView.snp.bottom)
     make.left.right.equalToSuperview()
     make.bottom.equalTo(self.bottomBar.snp.top)
}
UIView.animate(withDuration: 0.3) {
    self.view.layoutIfNeeded()
}
#写法3:
self.promptSuggestOrdersView.snp.remakeConstraints { (make) in
     make.left.top.right.equalToSuperview()
     make.height.equalTo(40)
}
self.tableView.snp.remakeConstraints { (make) in
     make.top.equalTo(self.promptSuggestOrdersView.snp.bottom)
     make.left.right.equalToSuperview()
     make.bottom.equalTo(self.bottomBar.snp.top)
}
UIView.animate(withDuration: 0.3, animations: {
    self.bgView.layoutIfNeeded()
    }, completion:nil)
#写法4: 当整个视图是在 scrollView 上的时候，为了适配 contentSize 空间，此时
UIView.animate(withDuration: 0.3, animations: {
    self.bgView.snp.remakeConstraints { (make) in
        make.top.equalTo(self.oldShop.snp.bottom).offset(25)
        make.leading.trailing.equalTo(self.view).inset(20)
        make.height.equalTo(300)
    }
    self.bgViewTwo.snp.remakeConstraints { (make) in
        make.left.right.equalTo(self.view).inset(20)
        make.top.equalTo(self.bgView.snp.bottom).offset(15)
        make.height.equalTo(0)
    }
    self.view.layoutIfNeeded()
    self.scrollView.contentSize.height = self.nextLogin.frame.maxY+100
})

给View视图添加部分圆角,需要注意的是使用贝塞尔曲线时要在视图布局以后才有效果。

override func viewDidLayoutSubviews() {
        cardView.roundCorners(cornerRadius: 20.0, corners: [.topLeft, .topRight])
    }
    
}
extension UIView {
    // 使用贝塞尔曲线添加部分圆角。 .allCorners/[.topLeft, .topRight]
    func roundCorners(cornerRadius: Double, corners: UIRectCorner) {
        let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: cornerRadius, height: cornerRadius))
        let maskLayer = CAShapeLayer()
        maskLayer.frame = self.bounds  // 可有可无
        maskLayer.path = path.cgPath
        self.layer.mask = maskLayer
    }
    // 使用贝塞尔曲线将所有角设置为圆角
    func roundCorners(cornerRadius: CGFloat) {
        let path = UIBezierPath(roundedRect: self.bounds, cornerRadius: cornerRadius)
        let maskLayer = CAShapeLayer()
        maskLayer.frame = self.bounds  // 可有可无
        maskLayer.path = path.cgPath
        self.layer.mask = maskLayer
    }
}