核心 ： 

/// 获取 子控件高度    func sizeHeaderToFit(view:UIView)  {        view.setNeedsLayout()        view.layoutIfNeeded()        let width = view.systemLayoutSizeFitting(UILayoutFittingCompressedSize).width        let height = view.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height    }

　　

可以参考 :

https://blog.csdn.net/longshihua/article/details/78595502

 

1. headerView 设置

import UIKitclass JYNewCardDetailHeaderV: UIView {    /// 储值卡总耗卡    let dyczkzhkLabel = UILabel(text: "储值卡总耗卡", fontSize: 16, isSetBoldFontSize: true, textColor: UIColor.init(hexColor: "424242"), textAlignment: .left)        override init(frame: CGRect) {        super.init(frame: frame)        setupUI()    }        required init?(coder aDecoder: NSCoder) {        fatalError("init(coder:) has not been implemented")    }        func configData(){            }}extension JYNewCardDetailHeaderV{        func setupUI() {    //VFL或者 layout设置 要把这个设置为false , snapkit 正常设置,不写的话界面也正常，就是报约束错误        self.translatesAutoresizingMaskIntoConstraints = false        let vd : [String:UIView] = ["dyczkzhkLabel":dyczkzhkLabel        vd.fastAddToView(self)        self.fastAddConstraints("|[dyczkzhkLabel]|", vd)        self.fastAddConstraints("V:|-10-[dyczkzhkLabel]-10-|", vd)    }}

　　

2. 使用这个view的地方配置

import Foundationprivate let cellID = "JYNewCardDetailCell"class JYStatmentCarView: UIView {       1.  //创建headerV    let headerV = JYNewCardDetailHeaderV(frame: CGRect.zero)   //创建tableview    fileprivate lazy var tableView : UITableView = {        let tableView = UITableView.init(frame: CGRect.zero, style: .plain)        tableView.delegate = self        tableView.dataSource = self        tableView.separatorStyle = .none        tableView.register(JYNewCardDetailCell.self, forCellReuseIdentifier: cellID)        return tableView    }()            override init(frame: CGRect) {        super.init(frame: frame)        self.translatesAutoresizingMaskIntoConstraints = false        self.configUI()    }    //3.重新计算header的frame    override func layoutSubviews() {        super.layoutSubviews()        sizeHeaderToFit()    }            /// 重置 tableview的header的frame    func sizeHeaderToFit() {        let headerView = tableView.tableHeaderView                headerView?.setNeedsLayout()        // 立马布局子视图        headerView?.layoutIfNeeded()                let height = headerView?.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height ?? 0        var frame = headerView?.frame ?? CGRect.zero        frame.size.height = height        headerView?.frame = frame        // 重新设置tableHeaderView        tableView.tableHeaderView = headerView    }        required init?(coder aDecoder: NSCoder) {        fatalError("init(coder:) has not been implemented")    }    /// 布局UI    private func configUI() {        DDLOG(message: "创建卡相关")                let vd : [String:UIView] = ["tableView":tableView]        let metrics: [String: Any] = [ "DeviceWidth": JY_DEVICE_WIDTH]        vd.fastAddToView(self)        self.fastAddConstraints("|[tableView(DeviceWidth)]|", vd, [], metrics)        self.fastAddConstraints("V:|[tableView]|", vd, [], metrics)            //2.设置tableview的headerView, 并且一定设置headerV的约束        tableView.tableHeaderView = headerV 　　　　 　　　　//VFL设置        headerV.topAnchor.constraint(equalTo: headerV.superview?.topAnchor ?? tableView.topAnchor).fastActive()        headerV.leftAnchor.constraint(equalTo: self.leftAnchor).fastActive()        headerV.rightAnchor.constraint(equalTo: self.rightAnchor).fastActive() 　　　　//snapkit 设置//        headerV.snp.makeConstraints { (make) in//            make.top.equalToSuperview()//            make.left.right.equalTo(self)//        }    }    }// MARK:- 代理extension JYStatmentCarView:UITableViewDelegate , UITableViewDataSource {    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {        return 10    }        func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {        let cell = tableView .dequeueReusableCell(withIdentifier: cellID, for: indexPath) as! JYNewCardDetailCell        cell.configData()        return cell    }        func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {        return UITableViewAutomaticDimension    }        func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {        return UITableViewAutomaticDimension    }}