Swift5.x入门22 -- 开发过程中遇到的问题记录

判断实例对象的类型

• 现有SFHomeViewController继承自SFBaseTableViewController
• 测试代码如下：

class AppDelegate: UIResponder, UIApplicationDelegate {
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        let vc = SFBaseTableViewController()
        
        if type(of: vc) == SFBaseTableViewController.self {
            print("1111") //打印
        }
        
        if type(of: vc) == SFHomeViewController.self {
            print("1111") //不打印
        }
        
        if vc.isMember(of: SFBaseTableViewController.self) {
            print("1111") //打印
        }
        
        if vc.isMember(of: SFHomeViewController.self) {
            print("1111")  //不打印
        }
        
        if vc.isKind(of: SFBaseTableViewController.self) {
            print("1111") //打印
        }
       
        if vc.isKind(of: SFHomeViewController.self) {
            print("1111") //不打印
        }
        
        if vc is SFBaseTableViewController {
            print("1111") //打印
        }
        
        if vc is SFHomeViewController {
            print("1111") //不打印
        }
    
        return true
    }
}

• type(of: 实例对象)与vc.isMember(of: 元类型值)功能等价，实例对象只在当前类进行比较；
• 实例对象 is 类名与vc.isKind(of: 元类型值)功能等价，实例对象在其继承链上进行比较；
• 针对iOS中私有类，例如UITableViewCellContentView，可采用view.isKind(of: NSClassFromString("UITableViewCellContentView")!)，不能使用元类型(会报错)；

委托代理协议的使用

• 自定义view，代码如下：

protocol SFCateRightViewDelegate : NSObjectProtocol {
    func headerRefresh() -> Void
    func footerRefresh() -> Void
    func didSelectedSmallCategory(smallCategory: CategorySmallModel) -> Void
}

class SFCateRightView: SFBaseView {
    //代理属性 使用weak指针 解决循环引用问题
    weak var deletegate: SFCateRightViewDelegate?

    //下拉刷新
    func loadRefreshData() -> Void {
        deletegate?.headerRefresh()
    }
    
    //上拉加载
    func loadMoreData() -> Void {
        deletegate?.footerRefresh()
    }
    
    private lazy var header: SFRefreshHeader = {
        let header = SFRefreshHeader(refreshingBlock: { [weak self] in
            self?.loadRefreshData()
        })
        return header
    }()

    private lazy var footer: SFRefreshFooter = {
        let footer = SFRefreshFooter(refreshingBlock: { [weak self] in
            self?.loadMoreData()
        })
        return footer
    }()
}

• 控制器代码如下：

import UIKit

class SFCategoryController: SFBaseViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        self.isNavBackItemHidden = true
        self.loadCategory()
    }
    
    override func createUI() {
        self.view.addSubview(self.rightView)
        self.rightView.deletegate = self
    }
    
    override func layoutSubControls() {
        self.rightView.snp.makeConstraints { (make) in
            make.top.equalTo(CGFloat(Navigation_Bottom_Y))
            make.right.equalTo(self.view)
            make.height.equalTo(kScreenHeight - kTabbarHeight - Navigation_Bottom_Y)
            make.width.equalTo(kScreenWidth/4*3)
        }
    }
    
    //MARK: -- lazy
    private lazy var rightView: SFCateRightView = {
        let rightView = SFCateRightView()
        rightView.backgroundColor = UIColor.white
        return rightView
    }()
}

extension SFCategoryController: SFCateRightViewDelegate {
    func didSelectedSmallCategory(smallCategory: CategorySmallModel) {
        self.page = 1
        self.isDownRefresh = true
        loadGoods(categoryId: self.selectedSmallCategoryModel!.mallCategoryId!, categorySubId: smallCategory.mallSubId!, page: self.page)
    }
    
    func headerRefresh() {
        self.page = 1
        self.isDownRefresh = true
        loadGoods(categoryId: self.selectedCategoryModel!.mallCategoryId!, categorySubId: self.selectedSmallCategoryModel!.mallSubId!, page: self.page)
    }
    
    func footerRefresh() {
        self.page += 1
        self.isDownRefresh = false
        loadGoods(categoryId: self.selectedCategoryModel!.mallCategoryId!, categorySubId: self.selectedSmallCategoryModel!.mallSubId!, page: self.page)
    }
}

函数闭包使用 等价于OC中的Block

• 自定义view，代码如下：

import UIKit

class SFCateLeftView: SFBaseView {
    //定义函数闭包    
    var didSelectCategoryBlock: ((SFCategoryModel,IndexPath) -> Void)?
    
    override func createUI() {
        self.addSubview(self.tableView)
    }

    override func layoutSubControls() {
        self.tableView.snp.makeConstraints { (make) in
            make.top.left.bottom.equalTo(self)
            make.width.equalTo(kScreenWidth/4-1)
        }
    }
    
    //MARK: --lazy
    private lazy var tableView: UITableView = {
        let tableView = UITableView(frame: .zero, style: UITableView.Style.plain)
        tableView.delegate = self
        tableView.dataSource = self
        tableView.backgroundColor = UIColor.white
        tableView.separatorStyle = .singleLine
        tableView.separatorColor = SF_LineColor_one
        tableView.separatorInset = UIEdgeInsets(top: 0, left: 15, bottom: 0, right: 0)
        if #available(iOS 11.0, *) {
            tableView.estimatedRowHeight = 0
            tableView.estimatedSectionHeaderHeight = 0
            tableView.estimatedSectionFooterHeight = 0
            tableView.contentInsetAdjustmentBehavior = .never
        } else {
            
        }
        //可隐藏没有数据的分割线
        let view = UIView()
        view.backgroundColor = UIColor.red
        tableView.tableFooterView = view;
        tableView.register(SFCateLeftCell.self, forCellReuseIdentifier: SFCateLeftCell.identifier())
        return tableView
    }()
}

extension SFCateLeftView: UITableViewDataSource,UITableViewDelegate {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.datas?.count ?? 0
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: SFCateLeftCell.identifier(), for: indexPath) as? SFCateLeftCell
        let model = self.datas![indexPath.row]
        cell!.model = model
        return cell!
    }
    
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 44.0
    }
    
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        print(indexPath.row)
        let model = self.datas![indexPath.row]
        model.isSelected = true
        let preModel: SFCategoryModel = self.datas![self.selectedIndex!]
        preModel.isSelected = false
        self.selectedIndex = indexPath.row
        tableView.reloadData()
        //调用函数闭包
        self.didSelectCategoryBlock?(model,indexPath)
    }
}

• 控制器代码：

import UIKit

class SFCategoryController: SFBaseViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        self.isNavBackItemHidden = true
        self.loadCategory()
    }
    
    override func createUI() {
        self.view.addSubview(self.leftView)
        //初始化函数闭包
        self.leftView.didSelectCategoryBlock = { [weak self] (model: SFCategoryModel,indexPath: IndexPath) in
            print(model.mallCategoryName!)
            guard let strongSelf = self else { return }
            
            let smallCategorys = model.bxMallSubDto
            //刷新右侧顶部数据
            strongSelf.rightView.smallCategorys = smallCategorys
            strongSelf.selectedCategoryModel = model
            strongSelf.selectedSmallCategoryModel = strongSelf.rightView.selectedSmallCategoryModel
            strongSelf.isDownRefresh = true
            strongSelf.page = 1
            //加载商品数据
            strongSelf.loadGoods(categoryId: model.mallCategoryId!, categorySubId: strongSelf.selectedSmallCategoryModel!.mallSubId!, page: strongSelf.page)
        }
    }
    
    override func layoutSubControls() {
        self.leftView.snp.makeConstraints { (make) in
            make.left.equalTo(self.view)
            make.top.equalTo(CGFloat(Navigation_Bottom_Y))
            make.height.equalTo(kScreenHeight - kTabbarHeight - Navigation_Bottom_Y)
            make.width.equalTo(kScreenWidth/4)
        }
    }
    
    //MARK: -- lazy
    private lazy var leftView: SFCateLeftView = {
        let leftView = SFCateLeftView()
        leftView.backgroundColor = UIColor.red
        return leftView
    }()
}