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Swift日常开发随笔

1、修改UISearchBar的搜索框底色

使用以下代码:
setSearchFieldBackgroundImage(CommonUseClass._sharedManager.imageFromColor(color: .white, viewSize: CGSize(width: self.bounds.size.width, height: self.bounds.size.height)), for: .normal)
 
//颜色创建图片
    func imageFromColor(color: UIColor, viewSize: CGSize) -> UIImage{
        let rect: CGRect = CGRect(x: 0, y: 0, width: viewSize.width, height: viewSize.height)
        UIGraphicsBeginImageContext(rect.size)
        let context: CGContext = UIGraphicsGetCurrentContext()!
        context.setFillColor(color.cgColor)
        context.fill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsGetCurrentContext()
        return image!
    }

2、修改UITextField的placeholderLabel的默认字体颜色

inputTextField.text = "123"
//备注:因为苹果公司开发过程中使用的是懒加载,所以如果不提前进行设置储值,则不会创建“_placeholderLabel”,仅仅使用以下代码不会进行更改默认字体颜色
inputTextField.setValue(colorWithHexString("0x999999"), forKeyPath: "_placeholderLabel.textColor")

3、为UICollectionView添加headerView

//备注:UICollectionView跟UITableView在设置headerView时有少许的差别。UICollection使用的是一个UICollectionReusableView来进行创建
 
collectionView.register(UICollectionReusableView, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "UICollectionReusableView")
 
//实现代理方法
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
        let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier:"UICollectionReusableView", for: indexPath)
        headerView.addSubview(contentSearchBar)
        return headerView
    }
 
//起初时候使用上面的代理方法不知道为何没有执行,后来设置了以下值发现竟然OK了,也不知道为啥,反正就用了。
layout.headerHeight = 70

4、自定义轮播图的UIPageControl

//创建轮播视图
 
class NACustomBannerView: UIView, UIScrollViewDelegate {
    var timeInterval: TimeInterval = 1
     
    private var imageUrls: [String] = [String]()
    private var imageArray: [UIImageView] = [UIImageView]()
    private var tapAction: (Int) -> Void
    private var currentIndex: Int = 0
    private weak var timer: Timer?
     
    private lazy var scrollNode: UIScrollView = {
        let node = UIScrollView()
        node.scrollsToTop = false
        node.isPagingEnabled = true
        node.bounces = false
        node.frame = self.bounds
        node.delegate = self
        node.showsHorizontalScrollIndicator = false
        node.decelerationRate = UIScrollView.DecelerationRate(rawValue: 1)
        node.setContentOffset(CGPoint(x: self.frame.width, y: 0), animated: false)
        node.contentSize = CGSize(width: self.frame.size.width * 3.0, height: 0)
        return node
    }()
     
    lazy var pageControl: NACustomBannerPageControl = {
        let node = NACustomBannerPageControl(frame: CGRect(x: Int(UIScreen.main.bounds.width / 2 - 40), y: Int(self.frame.height - 15), width: 10 * self.imageUrls.count , height: 10))
        node.numberOfPages = self.imageUrls.count
        return node
    }()
     
    // MARK: - Public
    func resetCurrentPage(_ page: Int) {
        currentIndex = page
        pageControl.currentPage = page
        resetImageView()
        startTimer()
    }
     
    // MARK: - Init
    init(frame: CGRect, imageUrls: [String], tapAction action: @escaping(Int) -> Void) {
        self.imageUrls = imageUrls
        self.tapAction = action
        super.init(frame: frame)
         
        addImageView()
        addSubview(scrollNode)
        addSubview(pageControl)
        startTimer()
    }
     
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
 
    // MARK: - UIScrollViewDelegate
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        let contentOffsetX = scrollView.contentOffset.x
        // 设置图片信息
        if contentOffsetX == 2 * scrollView.frame.width {// 左滑
            currentIndex = getActualCurrentPage(calculatedPage: currentIndex + 1)
            resetImageView()
        } else if (contentOffsetX == 0) {// 右滑
            currentIndex = getActualCurrentPage(calculatedPage: currentIndex - 1)
            resetImageView()
        }
 
        // 设置 pageControl
        if contentOffsetX < scrollView.frame.width && contentOffsetX > 0 {
            if contentOffsetX <= scrollView.frame.width * 0.5 {
                pageControl.currentPage = getActualCurrentPage(calculatedPage: currentIndex - 1)
            } else if contentOffsetX > scrollView.frame.width * 0.5 {
                pageControl.currentPage = getActualCurrentPage(calculatedPage: currentIndex)
            }
        } else if contentOffsetX > scrollView.frame.width && contentOffsetX < scrollView.frame.width * 2 {
            if contentOffsetX >= scrollView.frame.width * 1.5 {
                pageControl.currentPage = getActualCurrentPage(calculatedPage: currentIndex + 1)
            } else if contentOffsetX < scrollView.frame.width * 1.5 {
                pageControl.currentPage = currentIndex
            }
        }
         
    }
     
    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
        scrollView.setContentOffset(CGPoint(x: self.frame.width, y: 0), animated: true)
        startTimer()
    }
     
    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        timer?.invalidate()
        timer = nil
    }
 
    // MARK: - Action
    @objc fileprivate func cycleViewDidClick(gesture: UITapGestureRecognizer) {
        print("点击了第\(currentIndex)张图")
        let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: frame.width, height: frame.height))
        imageView.kf.setImage(with: URL(string: imageUrls[currentIndex]))
        tapAction(currentIndex)
    }
     
    @objc fileprivate func autoScroll() {
        if imageUrls.count < 2 {
            return
        }
        scrollNode.setContentOffset(CGPoint(x: self.frame.width * 2, y: 0), animated: true)
    }
     
    func startTimer() {
        guard imageUrls.count > 0 else { return }
         
        if let myTimer = timer {
            myTimer.invalidate()
            timer = nil
        }
        timer = Timer.scheduledTimer(timeInterval: self.timeInterval, target: self, selector: #selector(autoScroll), userInfo: nil, repeats: true)
        RunLoop.current.add(timer!, forMode: RunLoop.Mode.common)
    }
     
    func invalidateTimer() {
        timer?.invalidate()
        timer = nil
    }
     
    fileprivate func addImageView() {
        var x: CGFloat = 0
        var pageIndex: NSInteger = self.imageUrls.count - 1
        for index in 0..<3 {
            let imgNode = UIImageView()
            x = CGFloat(index) * frame.width
            imgNode.frame = CGRect(x: x, y: 0, width: frame.width, height: frame.height)
            imgNode.kf.setImage(with: URL(string: imageUrls.count == 0 ? "" : (imageUrls[pageIndex])))
            imgNode.contentMode = .scaleAspectFill
            imgNode.clipsToBounds = true
             
            let gesture = UITapGestureRecognizer(target: self, action: #selector(cycleViewDidClick(gesture:)))
            imgNode.addGestureRecognizer(gesture)
            imgNode.isUserInteractionEnabled = true
            imageArray.append(imgNode)
            scrollNode.addSubview(imgNode)
             
            if imageUrls.count == 1 {
                pageIndex = 0
                scrollNode.isScrollEnabled = false
            } else {
                pageIndex = index == 0 ? 0 : 1
            }
        }
         
    }
     
    fileprivate func resetImageView(){
         
        let preIndex: NSInteger = getActualCurrentPage(calculatedPage: currentIndex - 1)
        let nextIndex: NSInteger = getActualCurrentPage(calculatedPage: currentIndex + 1)
         
        if imageUrls.count == 0 {
            return
        }
 
        imageArray[0].kf.setImage(with: URL(string: imageUrls[preIndex]))
        imageArray[1].kf.setImage(with: URL(string: imageUrls[currentIndex]))
        imageArray[2].kf.setImage(with: URL(string: imageUrls[nextIndex]))
         
        scrollNode.contentOffset = CGPoint(x: self.frame.width, y: 0)
    }
     
 
    fileprivate func getActualCurrentPage(calculatedPage page: NSInteger) -> NSInteger {
        if page == imageUrls.count {
            return 0
        } else if page == -1 {
            return imageUrls.count - 1
        } else {
            return page
        }
    }
}

自定义轮播视图

import UIKit
 
class NACustomBannerPageControl: UIView {
    let pageControlDiameter: Float = 5
    var currentPage: NSInteger = 0 {
        didSet {
            if oldValue == currentPage {
                return
            }
             
            if currentPage < oldValue {// 向右拉伸
                UIView.animate(withDuration: 0.3, animations: {
                    for dot in self.subviews {
                        var dotFrame = dot.frame
                        if dot.tag == self.currentPage {
                            dotFrame.size.width = CGFloat(self.pageControlDiameter * 2.0)
                            dot.backgroundColor = colorWithHexString("0xfdd000")
                            dot.frame = dotFrame
                             
                        } else if dot.tag <= oldValue && dot.tag > self.currentPage {
                            dotFrame.origin.x += CGFloat(self.pageControlDiameter)
                            dotFrame.size.width = CGFloat(self.pageControlDiameter)
                            dot.backgroundColor = .white
                            dot.frame = dotFrame
                        }
                    }
                })
                 
            } else {
                UIView.animate(withDuration: 0.3, animations: {
                    for dot in self.subviews {
                        var dotFrame = dot.frame
                        if dot.tag == self.currentPage {
                            dotFrame.size.width = CGFloat(self.pageControlDiameter * 2.0)
                            dotFrame.origin.x -= CGFloat(self.pageControlDiameter)
                            dot.backgroundColor = colorWithHexString("0xfdd000")
                            dot.frame = dotFrame
                             
                        } else if dot.tag > oldValue && dot.tag < self.currentPage {
                            dotFrame.origin.x -= CGFloat(self.pageControlDiameter)
                            dot.frame = dotFrame
                             
                        } else if dot.tag == oldValue {
                            dotFrame.size.width = CGFloat(self.pageControlDiameter)
                            dot.backgroundColor = .white
                            dot.frame = dotFrame
                        }
                    }
                })
                 
            }
             
        }
    }
    var numberOfPages: NSInteger = 0 {
        didSet {
            if self.numberOfPages == 0 {
                return
            }
            if self.subviews.count > 0 {
                for view in self.subviews {
                    view.removeFromSuperview()
                }
            }
 
            var dotX: Float = 0;
            var dotW: Float = pageControlDiameter;
            var bgColor: UIColor
            for i in 0..<numberOfPages {
                if i <= currentPage {
                    dotX = pageControlDiameter * 2.0 * Float(i)
                } else {
                    dotX = pageControlDiameter * 2 * Float(i) + pageControlDiameter
                }
                 
                if i == currentPage {
                    dotW = pageControlDiameter * 2;
                    bgColor = colorWithHexString("0xfdd000")
                } else {
                    dotW = pageControlDiameter;
                    bgColor = .white
                }
 
                let temp = UIView()
                temp.frame = CGRect(x: CGFloat(dotX), y: CGFloat(0), width: CGFloat(dotW), height: CGFloat(pageControlDiameter))
                temp.layer.cornerRadius = CGFloat(pageControlDiameter * 0.5)
                temp.layer.masksToBounds = true
                temp.backgroundColor = bgColor
                temp.tag = i
                addSubview(temp)
            }
 
        }
    }
     
}

自定义UIPageControl样式

func setUpTurnsChangeItem() -> Void {
        let x = (SCREEN_WIDTH - 335)/2
        let frame = CGRect(x: x, y: CGFloat(21), width: 335, height: 170)
        let urls = ["",              "",                  "",                    "",                    ""]
        cycleScrollView = NACustomBannerView(frame: frame, imageUrls: urls) { (index) in
            print("当前第\(index)张")
        }
        cycleScrollView.layer.masksToBounds = true
        cycleScrollView.layer.cornerRadius = 5.0
        container.addSubview(cycleScrollView)
         
    }

使用方法

效果图如下:

5、自定义下拉列表

import UIKit
 
class NACustomDropListView: UIView,UITableViewDelegate,UITableViewDataSource{
    fileprivate var cellid = "cellid"
    lazy  var titleArray = [String]()
    lazy  var tableArray = [[String]]()
    var screenWidth = SCREEN_WIDTH
    var screenHeight = SCREEN_HEIGHT
    var maskViewSS:UIView?
    var selectClosure:((_ tag:Int,_ row:Int)->Void)?
    init(frame: CGRect,tableArr:[[String]],selectClosure : @escaping (_ tag:Int,_ row:Int)->Void) {
        super.init(frame: frame)
        self.titleArray = tableArr.map({ (arr) -> String in
            return arr[0]
        })
        self.tableArray = tableArr
        self.selectClosure = selectClosure
        self.backgroundColor = UIColor.white
        self.setTitleButton()
        setMaskView()
        setTableView()
    }
     
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
     
     
    func setMaskView(){
        let height = Int(Int(SCREEN_HEIGHT) - 40 - Int(CommonUseClass._sharedManager.navigationBarHeight()))
        maskViewSS = UIView.init(frame: CGRect(x: 0, y: 40, width: Int(screenWidth), height:height))
        maskViewSS?.backgroundColor = newColorWithAlpha(0, 0, 0, 0.3)
        let tap = UITapGestureRecognizer.init(target: self, action: #selector(tapAction))
         
        maskViewSS?.alpha = 0
        maskViewSS?.addGestureRecognizer(tap)
         
    }
    @objc func tapAction(){
        for i in 0..<self.tableArray.count{
            let tableView = self.viewWithTag(100+i) as! UITableView
            let drop = self.viewWithTag(1000+i) as! NACustomDropListTitleView
 
            if tableView.frame.height>1{
                drop.isSelected = false
                UIView.animate(withDuration: 0.2, animations: {
                    tableView.frame = CGRect.init(x: 0, y: 40, width: UIScreen.main.bounds.width, height: 1)
                    self.maskViewSS?.alpha = 0
                }, completion: { (idCom) in
                    self.maskViewSS?.removeFromSuperview()
                })
 
            }
        }
    }
    func setTitleButton(){
        let totalArry:Array<Array<String>>  = self.tableArray
        let width:CGFloat = screenWidth / CGFloat(titleArray.count)
         
        for i in 0..<self.titleArray.count{
            let view = NACustomDropListTitleView.init(frame: CGRect.init(x: CGFloat(i)*width, y: 0, width: width, height: 44), title: titleArray[i])
            view.tag = 1000+i
            view.gesClosure = { (select)->Void in
                self.insertSubview(self.maskViewSS!, at: 0)
                UIView.animate(withDuration: 0.2, animations: {
                    self.maskViewSS?.alpha = 1
                })
                if select {
                     
                    for n in 0..<self.titleArray.count {
                        let drop = self.viewWithTag(1000+n) as! NACustomDropListTitleView
                        let tableView = self.viewWithTag(100+n) as! UITableView
                        if i == n {
                            drop.isSelected = true
                             
                             
                        }else{
                            drop.isSelected = false
                        }
                        let arr = totalArry[n] as [String]
//                        tableView.reloadData()
                         
                        if i == n {
                            UIView.animate(withDuration: 0.2, animations: {
                                let height2 = Int(arr.count) * 40 + 20
                                let height1 = Int(Int(SCREEN_HEIGHT) - 40 - Int(CommonUseClass._sharedManager.navigationBarHeight()))
                                 
                                tableView.frame = CGRect(x: 0, y: 40, width: Int(self.screenWidth), height: height2 > height1 ? height1 : height2)
                            })
                             
                        }else{
                            UIView.animate(withDuration: 0.2, animations: {
                                tableView.frame = CGRect.init(x: 0, y: 40, width: self.screenWidth, height: 1)
                            })
                        }
                    }
                }else{
                     
                    let tableView = self.viewWithTag(100+i) as! UITableView
                     
                     
                    UIView.animate(withDuration: 0.2, animations: {
                        tableView.frame = CGRect.init(x: 0, y: 40, width: self.screenWidth, height: 1)
                        self.maskViewSS?.alpha = 0
                    }, completion: { (idCom) in
                        self.maskViewSS?.removeFromSuperview()
                    })
                     
                }
                 
            }
            self.addSubview(view)
             
        }
    }
    func setTableView(){
        let totalArry:Array<Array<String>>  = self.tableArray
         
         
         
        for i in 0..<totalArry.count{
             
            let tableView = UITableView.init(frame: CGRect.init(x: 0, y: 40, width: screenWidth, height: 1), style: .plain)
             
             
            tableView.delegate = self
            tableView.dataSource = self
            tableView.tag = 100+i
            tableView.backgroundColor = UIColor.white
            tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellid)
            tableView.rowHeight = 40
            tableView.isScrollEnabled = false
            tableView.separatorStyle = .none
            self.addSubview(tableView)
             
             
        }
    }
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        var view = super.hitTest(point, with: event)
        if view == nil {
            for subView in self.subviews {
                let tp = subView.convert(point, from: self)
                if subView.bounds.contains(tp) {
                    view = subView
                }
            }
        }
        return view
    }
     
     
     
}
extension NACustomDropListView{
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let drop = self.viewWithTag(tableView.tag-100+1000) as! NACustomDropListTitleView
        let cell = tableView.cellForRow(at: indexPath)
         
        drop.title  = cell?.textLabel?.text
        if self.selectClosure != nil {
            self.selectClosure!(tableView.tag,indexPath.row)
        }
         
        drop.isSelected = false
        UIView.animate(withDuration: 0.2, animations: {
            tableView.frame = CGRect.init(x: 0, y: 40, width: self.screenWidth, height: 1)
            self.maskViewSS?.alpha = 0
        }, completion: { (idCom) in
            self.maskViewSS?.removeFromSuperview()
        })
         
         
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let drop = self.viewWithTag(tableView.tag-100+1000) as! NACustomDropListTitleView
        if drop.isSelected == nil {
            return 0
        }else{
            return  drop.isSelected! ? self.tableArray[tableView.tag-100].count : 0
        }
         
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: cellid, for: indexPath) as UITableViewCell
        cell.textLabel?.font = UIFont.systemFont(ofSize: 14)
        cell.textLabel?.text = tableArray[tableView.tag - 100][indexPath.row]
         
        return cell
    }
}

自定义下拉列表View

import UIKit
import SnapKit
typealias GesClosure = (_ selected:Bool)->Void
class NACustomDropListTitleView: UIView {
    var label:UILabel!
    var downIcon:UIImageView!
    var topIcon:UIImageView!
     
    var ly_width:CGFloat?
    var title:String?{
        didSet{
            self.ly_width = CommonUseClass._sharedManager.getStringRect(text: self.title!,font: UIFont.systemFont(ofSize: 16)).width + 2
            label.text = self.title
            if title == "价格"{
                centerLayoutConstraints()
            }else{
                commponLayoutConstraints()
            }
             
        }
    }
    var _isSelect:Bool = false
    var gesClosure:GesClosure?
    var isSelected:Bool?{
        didSet{
            self._isSelect = isSelected!
            if isSelected! {
                self.downIcon.image = UIImage.init(named: "ic_down_y")
                self.label.textColor = colorWithHexString("0xfdd000")
            }else{
                self.downIcon.image = UIImage.init(named: "ic_down_f")
                self.label.textColor = colorWithHexString("0x000000")
            }
 
        }
    }
    init(frame: CGRect,title:String) {
        super.init(frame: frame)
        self.title = title
        self.ly_width = CommonUseClass._sharedManager.getStringRect(text: self.title!,font: UIFont.systemFont(ofSize: 16)).width + 2
        setUI(title: title)
        if title == "价格" {
            centerLayoutConstraints()
        }else{
            commponLayoutConstraints()
        }
         
        setGes()
    }
     
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    func setGes(){
        let ges = UITapGestureRecognizer.init(target: self, action: #selector(tapAction))
         
        self.addGestureRecognizer(ges)
    }
     
    @objc func tapAction(){
        self._isSelect = !self._isSelect
        self.isSelected = self._isSelect
        if (self.gesClosure != nil){
            self.gesClosure!(self.isSelected!)
        }
         
    }
     
    func setUI(title:String){
         
        label = UILabel()
        addSubview(label)
        label.font = UIFont.systemFont(ofSize: 16)
        label.textColor = colorWithHexString("0x000000")
        label.text = self.title
         
        downIcon = UIImageView.init()
        downIcon.image = UIImage.init(named:"ic_down_f")
        addSubview(downIcon)
         
        topIcon = UIImageView.init()
        topIcon.image = UIImage.init(named:"ic_down_f")
        addSubview(topIcon)
        UIView.animate(withDuration: 0.2, animations: {
            self.topIcon.transform = CGAffineTransform.init(rotationAngle: CGFloat(Double.pi))
             
        })
    }
     
    func labelConstraints() -> Void {
        label.snp.removeConstraints()
        downIcon.snp.removeConstraints()
        label.snp.makeConstraints { (make) in
            make.centerY.equalTo(self)
            make.centerX.equalTo(self)
            make.height.equalTo(16)
            make.width.equalTo(ly_width!)
        }
    }
    func commponLayoutConstraints(){
        labelConstraints()
        downIcon.snp.makeConstraints { (make) in
            make.left.equalTo(label.snp.right).offset(2)
            make.centerY.equalTo(label)
            make.width.equalTo(12)
            make.height.equalTo(6)
             
        }
    }
     
    func centerLayoutConstraints() -> Void {
        labelConstraints()
         
        topIcon.snp.makeConstraints { (make) in
            make.left.equalTo(label.snp.right).offset(2)
            make.top.equalTo(label).offset(1)
            make.width.equalTo(12)
            make.height.equalTo(6)
        }
         
        downIcon.snp.makeConstraints { (make) in
            make.left.equalTo(label.snp.right).offset(2)
            make.bottom.equalTo(label).offset(-1)
            make.width.equalTo(12)
            make.height.equalTo(6)
             
        }
         
         
    }
 
}

自定义下拉列表titleView

lazy var dropListView : NACustomDropListView = {
        let dropListView = NACustomDropListView.init(frame: CGRect(x: CGFloat(0), y: 0, width: SCREEN_WIDTH, height: CGFloat(44)), tableArr: [moneyArray,limitArray,sortArray], selectClosure: { (tag, row) in
            print(tag-100,row)
        })
        return dropListView
    }()
 
view.addSubview(dropListView)

使用方法

运行效果:

提示:之所以为空白,是因为我把下拉列表中的tableView.reloadData()这行代码屏蔽掉了,加入的数组没有刷新。

6、隐藏navigationBar和tabbar的黑色分割线

//隐藏navigationBar下面的分割线
self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .any, barMetrics: .default)
self.navigationController?.navigationBar.shadowImage = UIImage()
 
//隐藏tabbar上面的分割线
self.tabBarController?.tabBar.shadowImage = UIImage.init()
self.tabBarController?.tabBar.backgroundImage = UIImage.init()

 7、获取导航栏+状态栏的高度

func navigationBarHeight() -> Float {
        var navigationBarH: Float = 64
        if IS_IPHONE_X.boolValue {
            navigationBarH += 20
        }else{
            navigationBarH += 0
        }
        return navigationBarH
    }

8、判断字符串是否为空

func StringIsEmpty(value: AnyObject?) -> Bool {
        if (nil == value) {
            return true
        }else{
            if let myValue  = value as? String{
                return myValue == "" || myValue == "(null)" || 0 == myValue.count
            }else{
                return true
            }
        }
    }

9、判断是否是整数

func isPurnInt(string: String) -> Bool {
        let scan: Scanner = Scanner(string: string)
        var val:Int = 0
        return scan.scanInt(&val) && scan.isAtEnd
    }

10、添加阴影效果

func setShadow(view:UIView,sColor:UIColor,offset:CGSize,
                   opacity:Float,radius:CGFloat) {
        view.layer.shadowColor = sColor.cgColor
        view.layer.shadowOpacity = opacity
        view.layer.shadowRadius = radius
        view.layer.shadowOffset = offset
    }
 
使用实例:setShadow(view: groundView, sColor: .black, offset: CGSize(width: 1, height: 1), opacity:0.15, radius: 5)

11、颜色创建图片

func imageFromColor(color: UIColor, viewSize: CGSize) -> UIImage{
        let rect: CGRect = CGRect(x: 0, y: 0, width: viewSize.width, height: viewSize.height)
        UIGraphicsBeginImageContext(rect.size)
        let context: CGContext = UIGraphicsGetCurrentContext()!
        context.setFillColor(color.cgColor)
        context.fill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsGetCurrentContext()
        return image!
    }

12、获取字符串的宽度、高度

func getStringRect(text:String, font:UIFont) -> CGRect {
        let strText: NSString = NSString( string: text )
        let size:CGSize = CGSize(width: 100, height: 0)
        let options:NSStringDrawingOptions = NSStringDrawingOptions.usesLineFragmentOrigin
        let boundRect = strText.boundingRect(with: size, options: options, attributes: [NSAttributedString.Key.font: font], context: nil)
        return boundRect
    }

所用代码:均是swift 4.2下运行

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