Swift开发遇到问题二

1.获取类名方法

extension NSObject{
    //获取类名方法
    class func classNameAsString(_ obj: Any) -> String {
          //prints more readable results for dictionaries, arrays, Int, etc
          return String(describing: type(of: obj))
    }
}

可以扩展NSObject 全局调用

2.UITableViewCell注册cell方法

public static func cellWithTableView(tableView:UITableView)->FeedBackDetailTableViewCell{
    let identify = classNameAsString(FeedBackDetailTableViewCell())
    var cell: FeedBackDetailTableViewCell?
    cell = tableView.dequeueReusableCell(withIdentifier: identify as String ) as? FeedBackDetailTableViewCell
    if cell == nil  {
        cell = (Bundle.main.loadNibNamed(identify as String, owner: nil, options: nil)?.first as! FeedBackDetailTableViewCell)
    }
    return cell!
}

封装注册UITableViewCell的方法

extension UITableView {

    /// 获取缓存池中的cell
    /// - Parameter cellClass: 需要获取的cell类
    /// - Returns: cell
    func dequeueCellFromNib<T: UITableViewCell>(cellClass: T.Type) -> T{
        var cell: T?
        cell = self.dequeueReusableCell(withIdentifier: "\(cellClass)") as? T
        if cell == nil  {
            cell = (Bundle.main.loadNibNamed("\(cellClass)", owner: nil, options: nil)?.first as? T)
        }
        return cell!
    }

    /// 获取缓存池中的cell
    /// - Parameters:
    ///   - cellClass: 需要获取的cell类
    ///   - cellStyle: cellStyle 默认default
    /// - Returns: cell
    func dequeueCell<T: UITableViewCell>(cellClass: T.Type, _ cellStyle: T.CellStyle? = .default) -> T{
        var cell: T?
        cell = self.dequeueReusableCell(withIdentifier: "\(cellClass)") as? T
        if cell == nil  {
            cell = T.init(style: cellStyle!, reuseIdentifier: "\(cellClass)")
        }
        return cell!
    }
}

调用注册cell方法

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    //调用注册cell方法
    let cell = tableView.dequeueCellFromNib(cellClass: FeedBackDetailTableViewCell.self)

    cell.selectionStyle = .none//设置cell点击效果
    guard viewModel.dataArray.count > indexPath.row else {
        return cell
    }
    cell.feedBackDetailModel = viewModel.dataArray[indexPath.row]
    return cell
}

3.Swift 九宫格

let xa : CGFloat = 0 //x 初始值
let ya : CGFloat = 0 //y 初始值

let xz : CGFloat = 5//横向间隔
let yz : CGFloat = 10 //纵向间隔

let Width = (ScreenWidth-15*2-xz*3)/4
let Height = (ScreenWidth-15*2-xz*3)/4
for  i in 0..<imageArray.count {
    let X = xa+(xz + Width)*CGFloat((i % 4))
    let Y = ya+(yz + Height)*CGFloat((i / 4))
    let imageView = UIImageView(frame:CGRect(x:X, y:Y, width:Width, height:Height))
    let imageStr = imageArray[i] as! String
    imageView.kf.setImage(with: KfnisherImageResource(urlString:imageStr))
    photoView.addSubview(imageView)
}

4.Swift 判断 / %

两数相除或者取余之前都需转成Int类型

let chu = (images?.count ?? 0) / 4 //整除
let yu = (images?.count ?? 0) % 4 //取余
let rowHeight = Int((ScreenWidth-15*2-xz*3)/4) //图片宽度高度
let lineHeight = 10 //上下图片间距

if chu == 0 { //两数相除除数为0 则为未被整除如2/4则只有一行
    make.height.equalTo(rowHeight+lineHeight)
}else{
    if yu == 0 { //两数相除余数为0 则为被整除如4/4或者8/4
        make.height.equalTo((rowHeight+lineHeight)*chu+lineHeight)
    }else{ //两数相除余数不为0 则为被整除如6/4或者7/4
        make.height.equalTo((rowHeight+lineHeight)*chu+rowHeight+lineHeight)
    }
}

5.Swift SnapKit更新约束

更新约束之前需要先移除之前的约束，再重新设置约束

codeView.snp.removeConstraints()
codeView.snp.makeConstraints { (make) in
    make.top.equalTo(phoneView.snp.bottom).offset(15)
    make.height.equalTo(45)
}

6.Swift根据是否是刘海屏判断iphone X

// NavBarHeight
let NavBarHeight : CGFloat = isIPhoneXSeries ? 88 : 64
// TabBarHeight
let TabBarHeight : CGFloat = isIPhoneXSeries ? 49 + 34 : 49

////Mark ----- 是否为iPhone X等全屏手机
public var isIPhoneXSeries: Bool {
    var iPhoneXSeries = false
    if UIDevice.current.userInterfaceIdiom != UIUserInterfaceIdiom.phone {
        return iPhoneXSeries
    }

    if #available(iOS 11.0, *)  {
        if let bottom = UIApplication.shared.delegate?.window??.safeAreaInsets.bottom {
            if bottom > CGFloat(0.0) {
                iPhoneXSeries = true
            }
        }
    }
    return iPhoneXSeries
}