该demo是看
iOS-Swift开发项目-斗鱼直播APP 的视频后重写了一下
地址：https://www.bilibili.com/video/BV1qJ411B7G3?p=69
注：本文适合有一定的OC基础，Swift新手阅读

好了 斗鱼直播的 Swift版本上图

1.gif 2.gif 3.gif 4.gif

接下里分析从首页开始分析：
自定义导航栏：

image.png

  private func setNavigationBar(){
        
        navigationItem.leftBarButtonItem = UIBarButtonItem(imageName: "logo")
        let size = CGSize(width: 40, height: 40)
        let historyItem = UIBarButtonItem(imageName: "image_my_history", higtImageName: "Image_my_history_click", size: size)
        let searchItem = UIBarButtonItem(imageName: "btn_search", higtImageName: "btn_search_clicked", size: size)
        let qrcodeItem = UIBarButtonItem(imageName: "Image_scan", higtImageName: "Image_scan_click", size: size)
        navigationItem.rightBarButtonItems = [historyItem,searchItem,qrcodeItem]

    }

extension UIBarButtonItem{
    
    /*
     不建议这么写
     class func createItem(imageName: String, higtImageName:String ,size:CGSize) -> UIBarButtonItem{
            let btn  = UIButton()
            btn.setImage(UIImage(named: imageName), for: .normal)
            btn.setImage(UIImage(named: higtImageName), for: .highlighted)
            btn.frame = CGRect(origin: .zero, size:size)
            return UIBarButtonItem(customView: btn)
        }
     */
    
    
    
    
    /*
     swift 建议构造函数
     1、构造函数不需要写返回值
     2、在extension 只能扩充便利构造函数 convenience 加上开头便利构造函数
     3、必须 明确调用一个设计的构造函数（self）
     
     */
    
    /*
     默认字符串
     higtImageName:String = ""
     
     */
    
    convenience init(imageName: String, higtImageName:String = "" ,size:CGSize = .zero) {
        let btn  = UIButton()
        btn.setImage(UIImage(named: imageName), for: .normal)
        
        if higtImageName != "" {
            btn.setImage(UIImage(named: higtImageName), for: .highlighted)
        }
        if size == .zero {
            //按钮大小自适应
            btn.sizeToFit()
        }else{
            btn.frame = CGRect(origin: .zero, size:size)
        }
        
        self.init(customView:btn)
    }
    
   
}

自定定顶部滚动条

image.png

class JFPageTitleView: UIView {
    
    private var titles:[String]
    //懒加载一个数组
    private lazy var titleLabels:[UILabel] = [UILabel]()
    private var currentIndex:Int = 0
    //声明一个代理的属性
    weak var delegate:JFPageTitleViewDelegate?
     
    private lazy var scrollView:UIScrollView = {
        let scrollView = UIScrollView()
        scrollView.showsHorizontalScrollIndicator = false
        scrollView.scrollsToTop = false
        scrollView.isPagingEnabled = false
        scrollView.bounces = false
        return scrollView
    }()
    
    private lazy var scrollLine:UIView = {
        let scrollLine = UIView()
        scrollLine.backgroundColor = UIColor(r: KSelectColor.0, g: KSelectColor.1, b: KSelectColor.2, a: 1)
        return scrollLine
    }()
    
    init(frame: CGRect, titles:[String]) {
        self.titles = titles
        super.init(frame: frame)
        setupUI()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

extension JFPageTitleView{
    private func setupUI(){
        scrollView.frame = bounds        
        
        addSubview(scrollView)
        
        setupTitleLabel()
        
        setupBottomLineAndScrollLine()
    }
    
    private func setupTitleLabel(){
        //swift没有隐式转化的  一个是CGFloat 类型 一个是 int类型不能直接 乘除
         let labelW:CGFloat = frame.width / CGFloat(titles.count)
         let labelH:CGFloat = frame.height - KScrollLineH
         let labelY:CGFloat = 0
        
        for (index,title) in titles.enumerated() {
            let label = UILabel()
            label.text = title
            label.tag = index
            label.font = UIFont.systemFont(ofSize: 16)
            label.textColor = UIColor(r: KNormalColor.0, g: KNormalColor.1, b: KNormalColor.2, a: 1)
            label.textAlignment = .center
            let labelX:CGFloat = labelW * CGFloat(index)
            
            label.frame = CGRect(x: labelX, y: labelY, width: labelW, height: labelH)
            scrollView.addSubview(label)
            titleLabels.append(label)
            
            label.isUserInteractionEnabled = true
            let tapGes = UITapGestureRecognizer(target: self, action: #selector(self.labelClick(tapGes:)))
            label.addGestureRecognizer(tapGes)
            
        }
    }
    
    private func setupBottomLineAndScrollLine(){
        let bottomLine = UIView()
        let lineH:CGFloat = 0.5
        bottomLine.backgroundColor = UIColor(r: 234, g: 234, b: 234, a: 1)
        bottomLine.frame = CGRect(x: 0, y:frame.height - lineH, width: frame.width, height: lineH)
        addSubview(bottomLine)
        
//        titleLabels.first 是可选类型 用 guard进行判断
        guard let firstlabel  = titleLabels.first  else { return}
        firstlabel.textColor = UIColor(r: KSelectColor.0, g: KSelectColor.1, b: KSelectColor.2, a: 1)
        
        scrollView.addSubview(scrollLine)
        scrollLine.frame = CGRect(x: firstlabel.frame.origin.x, y: frame.height - KScrollLineH, width:firstlabel.frame.width, height: KScrollLineH)
    }
    
}

extension JFPageTitleView {
    // label点击
    @objc private func labelClick(tapGes:UITapGestureRecognizer){
        //当前的label
        guard let currentLabel = tapGes.view as? UILabel else {return}
        
        if currentLabel.tag == currentIndex {return}

        //old label
        let oldLabel = titleLabels[currentIndex]
        
        currentLabel.textColor = UIColor(r: KSelectColor.0, g: KSelectColor.1, b: KSelectColor.2, a: 1)
        oldLabel.textColor = UIColor(r: KNormalColor.0, g: KNormalColor.1, b: KNormalColor.2, a: 1)
        
        //保存最新label的下标值
        currentIndex = currentLabel.tag
        
        let scrollLineX = CGFloat(currentLabel.tag) * scrollLine.frame.size.width
        UIView.animate(withDuration: 0.15) {
            self.scrollLine.frame.origin.x = scrollLineX
        }
        
        //通知代理
        //代理必须是可选的 因为外部可以不遵守这个代理 所以是weak 修饰， "?"
        delegate?.JFPageTitleViewSelectAtIndex(titleView: self, selectIndex: currentIndex)
                
    }
}

//对外暴露方法
extension JFPageTitleView{
    func setTitleViewWithProgress(progress:CGFloat,sourceIndex:Int,targartIndex:Int){
        
        //取出label
        let sourceLabel = titleLabels[sourceIndex]
        let targartLabel = titleLabels[targartIndex]
        
        //处理滑块的逻辑
        let moveTotalX = targartLabel.frame.origin.x -  sourceLabel.frame.origin.x
        let moveX = moveTotalX * progress
        scrollLine.frame.origin.x = sourceLabel.frame.origin.x + moveX
        
        //颜色的渐变
        //取出变化范围
        let colorDelta =  (KSelectColor.0 - KNormalColor.0,
                           KSelectColor.1 - KNormalColor.1,
                           KSelectColor.2 - KNormalColor.2)
        
        
        //sourceLabel 是右 高亮边灰色 色值有大变小的过程
        sourceLabel.textColor = UIColor(r: KSelectColor.0 - colorDelta.0 * progress,
                                        g: KSelectColor.1 - colorDelta.1 * progress,
                                        b: KSelectColor.2 - colorDelta.2 * progress,
                                        a: 1)
        
        //targartLabel 是右 高亮边灰色 色值有小变大的的过程
        targartLabel.textColor = UIColor(r: KNormalColor.0 + colorDelta.0 * progress,
        g: KNormalColor.1 + colorDelta.1 * progress,
        b: KNormalColor.2 + colorDelta.2 * progress,
        a: 1)
        
        //记录currentIndex
        currentIndex = targartIndex
        
        
    }
}

contentView

image.png

private let KCcontentCellID = "KCcontentCellID"

//标明只能被类遵守  （如果不写也可以被 结构体，枚举遵守 不建议）这样不能把代理属性定义为可选类型
//定义一个协议
protocol JFPageContentViewDelegate : class {
    //声明一个协议的方法
    func JFPageContentViewScrollWith(pageContentView:JFPageContentView,progress:CGFloat, sourceIndex:Int,targetIndex:Int)
}

class JFPageContentView: UIView {
    
    weak var delegate:JFPageContentViewDelegate?
    
    private var childVcs:[UIViewController]
    
    private var startOffSetX:CGFloat = 0
    /*
     用weak修饰 是可选类型 用 “？”修饰
     'weak' variable should have optional type 'UIViewController?'
     */
    
    private var isForbidScrollDelegate:Bool = false
    
    private weak var parentViewController:UIViewController?
    
    private lazy var collectionView:UICollectionView = { [weak self] in
        let layout = UICollectionViewFlowLayout()
        
        /*
         weak self 是可选类型
         self.bounds.size self?.bounds.size 也是可选类型 但是 layout.itemSize 这个是确定类型
         (self?.bounds.size)!  “!”强制解包
         */
        layout.itemSize = (self?.bounds.size)!
        layout.minimumLineSpacing = 0
        layout.minimumInteritemSpacing = 0
        layout.scrollDirection = .horizontal
        
        let frame:CGRect = .zero
        let collectionView  = UICollectionView(frame: frame, collectionViewLayout: layout)
        collectionView.showsHorizontalScrollIndicator = false
        collectionView.isPagingEnabled = true
        collectionView.bounces = false
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: KCcontentCellID)
        return collectionView
    }()

   
    //构造函数改成可选类型
    init(frame: CGRect,childVcs:[UIViewController],parentViewController:UIViewController?) {
        self.childVcs = childVcs
        //可选类型 赋值给可选类型 OK的
        self.parentViewController = parentViewController
        super.init(frame: frame)
        setupUI()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

extension JFPageContentView{
    private func setupUI(){
        //将所有的子控制器加到父控制器中
        for childvc in childVcs {
            //如果是可选类型那么就是 要用可选链来调用
            parentViewController?.addChild(childvc)
        }
        addSubview(collectionView)
        collectionView.frame = bounds
    }
}

//遵守UICOllectionView 的datasource
extension JFPageContentView:UICollectionViewDataSource{
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return childVcs.count
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: KCcontentCellID, for: indexPath)
        
        //cell会循环引用 先移除
        for view in cell.contentView.subviews {
            view.removeFromSuperview()
        }
        
        //给cell设置内容
        let childVc = childVcs[indexPath.item]
        childVc.view.frame = cell.contentView.bounds
        cell.contentView.addSubview(childVc.view)
        return cell
        
    }
    
}

extension JFPageContentView:UICollectionViewDelegate{
    
    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        
        isForbidScrollDelegate = false
        
        startOffSetX =  scrollView.contentOffset.x
    }
    
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        
        if (isForbidScrollDelegate) {return}
        
        var progress:CGFloat = 0
        var sourceIndex:Int = 0
        var targetIndex:Int = 0
        
        //判断左滑还是右滑
        let currentOffSetX = scrollView.contentOffset.x
        let scrollViewW  = scrollView.bounds.width
        if startOffSetX > currentOffSetX { //左滑
            //计算progress
//            floor 取整
            progress = currentOffSetX / scrollViewW - floor(currentOffSetX / scrollViewW)
            
            //计算当前的 sourceIndex
            sourceIndex = Int(currentOffSetX / scrollViewW)
            
            //计算target
            targetIndex = sourceIndex + 1
            
            if targetIndex >= childVcs.count {
                targetIndex = childVcs.count - 1
            }
            
            //如果完全滑过去
            if currentOffSetX - startOffSetX ==  scrollViewW{
                progress = 1
                targetIndex = sourceIndex
            }
            
            
        }else{ //右滑
            progress = 1 - (currentOffSetX / scrollViewW - floor(currentOffSetX / scrollViewW))
            
            //计算target
            targetIndex = Int(currentOffSetX / scrollViewW)
            
            //计算当前的 sourceIndex
            sourceIndex = targetIndex + 1
            
            if sourceIndex >= childVcs.count {
                sourceIndex = childVcs.count - 1
            }
        }
        
        delegate?.JFPageContentViewScrollWith(pageContentView: self, progress: progress, sourceIndex: sourceIndex, targetIndex: targetIndex)

        
        
    }
}



//对外暴露的方法
extension JFPageContentView{
    func setCurrentIndex(currentIndex:Int) {
        
        //禁止执行scroll的代理
        isForbidScrollDelegate = true
        
        let offSetX = CGFloat(currentIndex) * collectionView.frame.width
        //设置collectionview的偏移量
        collectionView.setContentOffset(CGPoint(x: offSetX, y: 0), animated: false)
    }
}

网络请求：

import Alamofire

enum MethodType {
    case GET
    case POST
}

class JFNetworkTool{
    
    //字典类型 [String:NSString]
    //parameters:[String:NSString]? = nil, 默认参数 方便外面调用
    //callBack:()->() 闭包的写法 第一个（）里面添加参数
    
    //逃逸闭包 @escaping 闭包在另外一个闭包中使用需要  @escaping修饰
    //result:AnyObject 改成any 则callBack(result as AnyObject) 改成            callBack(result)
    /*
     parameters: parameters,
      encoding: URLEncoding.default,
      headers: nil).responseJSON { (response) in
     有默认参数 可以直接去掉
     */
    
    

    
    class func requestData(type:MethodType , urlString:String,parameters:[String:NSString]? = nil, callBack:@escaping (_ result:Any)->())  {
        
        //获取类型
        let method = type == .GET ? HTTPMethod.get : HTTPMethod.post
      
        Alamofire.request(urlString,
                          method:method ,
                          parameters: parameters).responseJSON { (response) in
            guard let result = response.result.value  else{
                print(response.result.error as Any)
                return}
            callBack(result)
        }
        
    }

}

KVC字典转模型

/// 子类可以继承父类的所有属性和方法 可以用来抽取 公共的属性和方法
class BaseGameModel: NSObject {
    
    //定义属性  swift 4.0 之后需要手动添加@objc 否则转模型会没有值
        @objc var tag_name : String = ""
        @objc var icon_url : String = ""

        init(dict:[String:Any]) {
           super.init()
           setValuesForKeys(dict)
        }
        //构造函数 在调用的时候 才可以用 AnchorGroup()来创建
        override init() {}

        override func setValue(_ value: Any?, forUndefinedKey key: String) {}

}

   override func setValue(_ value: Any?, forUndefinedKey key: String) {}

这个一定要重写 要不然 字段超出要解析的字段会奔溃

归纳下Swift一些常见且高频注意的点：

类型推导：

image.png

基本运算：

image.png image.png

逻辑分支Guard：

image.png

for 循环：

image.png
image.png

元祖

image.png image.png

可选类型

举例两种错误写法：

image.png image.png image.png image.png image.png
image.png

类型转换

image.png image.png image.png

本期就总结到这 下期继续 并上源码地址