UICollectionView highlight
// 方法一 func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) { cell.backgroundColor = .white let backgroundView = UIView(frame: cell.frame) backgroundView.backgroundColor = UIColor(white: 0.9, alpha: 1) cell.selectedBackgroundView = backgroundView } func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { collectionView.deselectItem(at: indexPath, animated: true) } // 方法二(有延时) func collectionView(_ collectionView: UICollectionView, didHighlightItemAt indexPath: IndexPath) { let cell = collectionView.cellForItem(at: indexPath) cell?.contentView.backgroundColor = UIColor(white: 0.9, alpha: 1) } func collectionView(_ collectionView: UICollectionView, didUnhighlightItemAt indexPath: IndexPath) { let cell = collectionView.cellForItem(at: indexPath) cell?.contentView.backgroundColor = nil }
泛型约束
protocol ArrayPresenter { associatedtype ViewType: UIScrollView var listView: ViewType! { set get } } func loadMore<T: UIScrollView>(listView: T, indexPath: NSIndexPath) where T: YourProtocol { }
银行金额验证
extension String { func enteredCorrectly() -> Bool { if length == 0 { return false } let scan = NSScanner(string: self) let isNotZero = Double(self) > 0 if isNotZero { if containsString(".") { if let rangeOfZero = rangeOfString(".", options: .BackwardsSearch) { let suffix = String(characters.suffixFrom(rangeOfZero.endIndex)) if suffix.length > 2 { showAlert(controller, message: "您输入的金额有误") return false } } var float: Float = 0 guard !(scan.scanFloat(&float) && scan.atEnd) else { return true } } else { var int: Int64 = 0 guard !(scan.scanLongLong(&int) && scan.atEnd) else { return true } } } return false } }
多标志符字符串分割
let text = "abc,vfr.yyuu" let set = CharacterSet(charactersIn: ",.") print(text.components(separatedBy: set)) // ["abc", "vfr", "yyuu"]
匹配模式
let age = 19 if 18...25 ~= age { print("条件满足") } 同 if age >= 18 && age <= 25 { print("条件满足") } 同 if case 18...25 = age { print("条件满足") }
单行代码
let arr = (1...1024).map{ 0ドル * 2 } let n = (1...1024).reduce(0,combine: +) let words = ["Swift","iOS","cocoa","OSX","tvOS"] let tweet = "This is an example tweet larking about Swift" let valid = !words.filter({ tweet.containsString(0ドル) }).isEmpty valid //true let valid2 = words.contains(tweet.containsString) valid2 //true // 埃拉托斯特尼筛法 var n = 102 var primes = Set(2...n) var sameprimes = Set(2...n) let aa = sameprimes.subtract(Set(2...Int(sqrt(Double(n)))) .flatMap{(2 * 0ドル).stride(through: n, by:0ドル)}) let bb = aa.sort() // bb [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101] let arr = [82, 58, 76, 49, 88, 90] let retulst = data.reduce(([], [])) { 1ドル < 60 ? (0ドル.0 + [1ドル], 0ドル.1) : (0ドル.0, 0ドル.1 + [1ドル]) } // retulst ([58, 49], [82, 76, 88, 90])
GCD map函数
extension Array { public func pmap(transform: (Element -> Element)) -> [Element] { guard !self.isEmpty else { return [] } var result: [(Int, [Element])] = [] let group = dispatch_group_create() let lock = dispatch_queue_create("pmap queue for result", DISPATCH_QUEUE_SERIAL) let step: Int = max(1, self.count / NSProcessInfo.processInfo().activeProcessorCount) // step can never be 0 for var stepIndex = 0; stepIndex * step < self.count; stepIndex += 1 { let capturedStepIndex = stepIndex var stepResult: [Element] = [] dispatch_group_async(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) { for i in (capturedStepIndex * step)..<((capturedStepIndex + 1) * step) { if i < self.count { let mappedElement = transform(self[i]) stepResult += [mappedElement] } } dispatch_group_async(group, lock) { result += [(capturedStepIndex, stepResult)] } } } dispatch_group_wait(group, DISPATCH_TIME_FOREVER) return result.sort { 0ドル.0 < 1ドル.0 }.flatMap { 0ドル.1 } } } extension Array { public func pfilter(includeElement: Element -> Bool) -> [Element] { guard !self.isEmpty else { return [] } var result: [(Int, [Element])] = [] let group = dispatch_group_create() let lock = dispatch_queue_create("pmap queue for result", DISPATCH_QUEUE_SERIAL) let step: Int = max(1, self.count / NSProcessInfo.processInfo().activeProcessorCount) // step can never be 0 for var stepIndex = 0; stepIndex * step < self.count; stepIndex += 1 { let capturedStepIndex = stepIndex var stepResult: [Element] = [] dispatch_group_async(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) { for i in (capturedStepIndex * step)..<((capturedStepIndex + 1) * step) { if i < self.count && includeElement(self[i]) { stepResult += [self[i]] } } dispatch_group_async(group, lock) { result += [(capturedStepIndex, stepResult)] } } } dispatch_group_wait(group, DISPATCH_TIME_FOREVER) return result.sort { 0ドル.0 < 1ドル.0 }.flatMap { 0ドル.1 } } }
导航栏标题设置
// 需要tabBarItem的title与导航栏title不一致,如下设置navigationbar的titile navigationItem.title = "示例" 注意: 直接 title = "示例" 在tabbar切换时tabBarItem的title会变成设置
tabbar隐藏动画(同知乎)
func setTabBarVisible(visible: Bool, animated: Bool) { //* This cannot be called before viewDidLayoutSubviews(), because the frame is not set before this time // bail if the current state matches the desired state if tabBarIsVisible == visible { return } // get a frame calculation ready let frame = tabBarController?.tabBar.frame let height = frame?.size.height let offsetY = (visible ? -height! : height) // zero duration means no animation let duration: NSTimeInterval = (animated ? 0.3 : 0.0) // animate the tabBar if let rect = frame { UIView.animateWithDuration(duration) { self.tabBarController?.tabBar.frame = CGRectOffset(rect, 0, offsetY!) return } } } var tabBarIsVisible: Bool { return tabBarController?.tabBar.frame.minY < view.frame.maxY }
导航栏标返回图片
navigationBar.backIndicatorTransitionMaskImage = R.image.ic_nav_back() navigationBar.backIndicatorImage = R.image.ic_nav_back()
tableView分割线左边到头(_UITableViewCellSeparatorView)
//写在viewDidLoad http://www.jianshu.com/p/1274343055a7 if tableView.respondsToSelector(Selector("setSeparatorInset:")) { tableView.separatorInset = UIEdgeInsetsZero } if tableView.respondsToSelector(Selector("setLayoutMargins:")) { tableView.layoutMargins = UIEdgeInsetsZero } //写在 willDisplayCell if cell.respondsToSelector(Selector("setSeparatorInset:")) { cell.separatorInset = UIEdgeInsetsZero } if cell.respondsToSelector(Selector("setLayoutMargins:")) { cell.layoutMargins = UIEdgeInsetsZero } override func layoutSubviews() { super.layoutSubviews() separatorInset = UIEdgeInsetsZero preservesSuperviewLayoutMargins = false layoutMargins = UIEdgeInsetsZero }
虚线
func drawDottedLine(lineView: UIView, offset: CGPoint) { let shapeLayer = CAShapeLayer() shapeLayer.bounds = lineView.bounds shapeLayer.position = lineView.layer.position shapeLayer.fillColor = nil shapeLayer.strokeColor = MOOTS_LINE_GRAY.CGColor shapeLayer.lineWidth = 0.5 shapeLayer.lineJoin = kCALineJoinRound // 4=线的宽度 1=每条线的间距 shapeLayer.lineDashPattern = [NSNumber(int: 4), NSNumber(int: 1)] let path = CGPathCreateMutable() CGPathMoveToPoint(path, nil, offset.x, offset.y) CGPathAddLineToPoint(path, nil, CGRectGetWidth(lineView.frame) - offset.x, offset.y) shapeLayer.path = path lineView.layer.addSublayer(shapeLayer) }
部分圆角图片
func cornerImage(frame: CGRect, image: UIImage, Radii: CGSize) -> UIImageView { let imageView = UIImageView(image: image) imageView.frame = frame let bezierPath = UIBezierPath(roundedRect: imageView.bounds, byRoundingCorners: [.TopLeft, .TopRight], cornerRadii: Radii) let shapeLayer = CAShapeLayer() shapeLayer.path = bezierPath.CGPath imageView.layer.mask = shapeLayer return imageView }
圆角图片(AlamofireImage里面有切圆角的方法)
extension UIImageView { func kt_addCorner(radius radius: CGFloat) { self.image = self.image?.kt_drawRectWithRoundedCorner(radius: radius, self.bounds.size) } } extension UIImage { func kt_drawRectWithRoundedCorner(radius radius: CGFloat, _ sizetoFit: CGSize) -> UIImage { let rect = CGRect(origin: CGPoint(x: 0, y: 0), size: sizetoFit) UIGraphicsBeginImageContextWithOptions(rect.size, false, UIScreen.mainScreen().scale) CGContextAddPath(UIGraphicsGetCurrentContext(), UIBezierPath(roundedRect: rect, byRoundingCorners: UIRectCorner.AllCorners, cornerRadii: CGSize(width: radius, height: radius)).CGPath) CGContextClip(UIGraphicsGetCurrentContext()) self.drawInRect(rect) CGContextDrawPath(UIGraphicsGetCurrentContext(), .FillStroke) let output = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return output } }
通过字符串构建类
extension String { func fromClassName() -> NSObject { let className = NSBundle.mainBundle().infoDictionary!["CFBundleName"] as! String + "." + self let aClass = NSClassFromString(className) as! UIViewController.Type return aClass.init() } } extension NSObject { class func fromClassName(className: String) -> NSObject { let className = NSBundle.mainBundle().infoDictionary!["CFBundleName"] as! String + "." + className let aClass = NSClassFromString(className) as! UIViewController.Type return aClass.init() } }
修改状态栏背景颜色
func setStatusBarBackgroundColor(color: UIColor) { guard let statusBar = UIApplication.sharedApplication().valueForKey("statusBarWindow")?.valueForKey("statusBar") as? UIView else { return } statusBar.backgroundColor = color } swift3.0 func setStatusBarBackgroundColor(color: UIColor) { let statusBarWindow = UIApplication.shared.value(forKey: "statusBarWindow") as? UIView guard let statusBar = statusBarWindow?.value(forKey: "statusBar") as? UIView else { return } statusBar.backgroundColor = color }
裁剪图片
extension UIImage { func cutOutImageWithRect(rect: CGRect) -> UIImage { guard let subImageRef = CGImageCreateWithImageInRect(CGImage, rect) else { return self } let smallBounds = CGRect(x: 0, y: 0, width: CGImageGetWidth(subImageRef), height: CGImageGetHeight(subImageRef)) UIGraphicsBeginImageContext(smallBounds.size) let context = UIGraphicsGetCurrentContext() CGContextDrawImage(context, smallBounds, subImageRef) let smallImage = UIImage(CGImage: subImageRef) UIGraphicsEndImageContext() return smallImage } }
UIButton响应区域太小
extension UIButton { //处理button太小 open override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? { // if the button is hidden/disabled/transparent it can't be hit if self.isHidden || !self.isUserInteractionEnabled || self.alpha < 0.01 { return nil } // increase the hit frame to be at least as big as `minimumHitArea` let buttonSize = bounds.size let widthToAdd = max(44 - buttonSize.width, 0) let heightToAdd = max(44 - buttonSize.height, 0) let largerFrame = bounds.insetBy(dx: -widthToAdd / 2, dy: -heightToAdd / 2) // perform hit test on larger frame return largerFrame.contains(point) ? self : nil } }
UIImage(named: "imageName")// caching
UIImage(contentsOfFile: "imageName")// no caching
如果你要加载一个大图片而且是一次性使用,那么就没必要缓存这个图片,用contentsOfFile足矣,这样不会浪费内存来缓存它。
然而,在图片反复重用的情况下named是一个好得多的选择。
- UITableView
在UITableViewCell实例上添加子视图,有两种方式:[cell addSubview:view]或[cell.contentView addSubview:view],一般情况下,两种方式没有区别。但是在多选编辑状态,直接添加到cell上的子视图将不会移动,而添加在contentView上的子视图会随着整体右移。所以,推荐使用[cell.contentView addSubview:view]方式添加子视图。
cell.backgroundColor = [UIColor grayColor];或cell.contentView.backgroudColor = [UIColor grayColor];一般情况下,两种方式效果一样。但是在多选编辑状态,直接设置cell的背景色可以保证左侧多选框部分的背景色与cell背景色一致,而设置contentView背景色,左侧多选框的背景色会是UITableView的背景色或UITableView父视图背景色,如果需要保证颜色一致,必须设置cell的背景色而不是cell.contentView的。
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UIButton setImage setBackgroundImage
首先setBackgroundImage,image会随着button的大小而改变,图片自动会拉伸来适应button的大小,这个时候任然可以设置button的title,image不会挡住title;相反的的setImage,图片不会进行拉伸,原比例的显示在button上,此时再设置title,title将无法显示,因此可以根据需求选中方法
- NSLayoutConstraint Leading left
NSLayoutAttributeLeading/NSLayoutAttributeTrailing的区别是left/right永远是指左右,
leading/trailing在某些从右至左习惯的地区(希伯来语等)会变成,leading是右边,trailing是左边
- Protocol
delegate一般得用weak标识符,这样当delegate指向的controller被销毁时,delegate会跟着被置为nil,可以有效防止这种问题。
若是使用assign标识的delegate,则注意在delegate指向的对象被销毁时,将delegate 置为nil。
也有不将delegate置为nil,没有问题的情况。如常见的tableView,其delegate和datasource,一般不会在其他controller中使用该tableView,所以不会有这种问题。
- Struct
实例方法中修改值类型
结构体和枚举是值类型。默认情况下,值类型的属性不可以在他的实例方法中修改
可以用mutating(变异行为)
注意:不能在结构体类型常量上调用变异方法,因为常量的属性不能被改变,即使想改变的是常量的变量属性也不行
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杂
-
Self 表示引用当前实例的类型
-
AnyObject可以代表任何class类型的实例
-
Any可以表示任何类型。除了方法类型(function types)
-
对于生命周期中会变为nil的实例使用弱引用。相反地,对于初始化赋值后再也不会被赋值为nil的实例,使用无主引用。
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Cocoapods原理
卸载当前版本 sudo gem uninstall cocoapods 下载旧版本 sudo gem install cocoapods -v 0.25.0
修改Xcode自动生成的文件注释来导出API文档
open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Templates/File\ Templates/Source
LLDB(断点调试)
删除多余模拟器
open /Library/Developer/CoreSimulator/Profiles/Runtimes
open /Users/你电脑的名字/Library/Developer/Xcode/iOS\ DeviceSupport
修改swift文件
open /Applications/Xcode.app/Contents/Developer/Library/Xcode/Templates/File\ Templates/Source/Swift\ File.xctemplate
open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Templates/File\ Templates/Source/Cocoa\ Touch\ Class.xctemplate/UIViewControllerSwift
1.The certificate used to sign "XXX" has either expired or has been revoked
2.解决cocoapods diff: /../Podfile.lock: No such file or directory
按字母排序,点击展开为该库的描述