swift--UIStackView的实用技巧

基础

这部分参考：原文地址

open var axis: NSLayoutConstraint.Axis // 子控件布局方向(水平或者垂直),也就是下面说的轴方向,
/**
case fill   沿轴方向填充视图.会按照优先级压缩或者拉伸子视图
case fillEqually    沿轴方向使子视图等宽或者等高
case fillProportionally     沿轴方向按照`intrinsic content`的比例压缩或者拉伸
case equalSpacing   沿轴按照优先级压缩或者拉伸子视图,使间隙相等
case equalCentering     沿轴方向子视图中心等分
*/
open var distribution: UIStackView.Distribution // 轴方向的控件布局方式
/**
case fill   垂直于轴方向填充视图
case center     子视图中心和轴线重合

case leading    .vertical 情况下使用,垂直于轴方向靠左
case trailing   .vertical 情况下使用,垂直于轴方向靠右

case top    .horizontal 情况下使用,子视图
public static var bottom: UIStackView.Alignment { get } .horizontal 情况下使用
case firstBaseline  .horizontal 情况下使用, 按照第一个子视图的baseline对齐,并保证最高视图底部对齐
case lastBaseline   .horizontal 情况下使用, 按照最后一个子视图的baseline对齐,并保证最高视图顶部对齐
*/
open var alignment: UIStackView.Alignment // 非轴方向的控件布局方式
open var spacing: CGFloat // 子控件的最小间距

 实用技巧

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

        //上部滚动页
        let scrollView = UIScrollView()
        scrollView.backgroundColor = UIColor.gray

        //底部标签
        let tabStack = UIStackView()

        for i in 0 ..< 4 {
            let btn = UIButton()
            btn.tag = 200 + i
            btn.setTitleColor(UIColor.black, for: UIControl.State.normal)
            btn.setTitle("\(i)", for: UIControl.State.normal)
            btn.addTarget(self, action: #selector(self.itemTouch(sender:)), for: UIControl.Event.touchUpInside)
            tabStack.addArrangedSubview(btn)
        }

        tabStack.axis = .horizontal
        tabStack.alignment = .fill
        tabStack.distribution = .fillEqually
        tabStack.heightAnchor.constraint(equalToConstant: 60).isActive = true

        let stackView = self.safeAreaStackView(arrangedSubviews: [scrollView,tabStack])
        stackView.axis = .vertical
        stackView.alignment = .fill
        stackView.distribution = .fill
    }
    
    @objc func itemTouch(sender:UIButton){
        print("page = \(sender.tag)")
    }
}

extension UIViewController {
    public func safeAreaStackView(arrangedSubviews: [UIView]) -> UIStackView {
        
        let isIphoneX = UIScreen.main.bounds.height >= 812 ? true : false
        
        var navigationBarHeight:CGFloat = isIphoneX ? 44 : 20
        var tabBarHeight:CGFloat = isIphoneX ? 34 : 0

        var noNavigationExists = true
        
        if let navigation = self.navigationController {
            noNavigationExists = false
            navigationBarHeight = navigationBarHeight + CGFloat(navigation.navigationBar.frame.height)
        }
        if let tabBarController = self.tabBarController {
            tabBarHeight = noNavigationExists ? tabBarHeight : 0
            tabBarHeight = tabBarHeight + CGFloat(tabBarController.tabBar.frame.height)
        }

        let view = UIStackView(arrangedSubviews: arrangedSubviews)
        view.translatesAutoresizingMaskIntoConstraints = false
        self.view.addSubview(view)
        //        创建约束
        let constraintArrayH = NSLayoutConstraint.constraints(withVisualFormat: "H:|-0-[View]-0-|", options: NSLayoutConstraint.FormatOptions(), metrics: nil, views: ["View":view])
        let constraintArrayV = NSLayoutConstraint.constraints(withVisualFormat: "V:|-\(navigationBarHeight)-[View]-\(tabBarHeight)-|", options: NSLayoutConstraint.FormatOptions(), metrics: nil, views: ["View":view])
        self.view.addConstraints(constraintArrayH)
        self.view.addConstraints(constraintArrayV)
        return view
    }
}

效果演示：