以下是2018年10月23日更新
經過大約一個月的時間的適配，項目正式使用XCode10(以下簡稱為10 or XC10)大部分庫都升級為Swift4.2（以下簡稱為 4.2 or S4.2），下面是適配過程中遇到的一些坑。
1. Swift4、Swift4.2混編
如果你對項目是小的獨立項目，完全可以全部升級為4.2，你可以略過第一條；如果你依賴了一些第三方的庫，且沒有升級4.2，你可以繼續看這一條。目前測試的結果來看，Swift4 和 S4.2的混編沒有什么大的問題，如果你是通過cocoapod引入的可以在Podfile中加入如下代碼：
swift_41_pod_targets = ['your_target_name']
post_install do |installer|installer.pods_project.targets.each do |target|if swift_41_pod_targets.include?(target.name)target.build_configurations.each do |config|config.build_settings['SWIFT_VERSION'] = '4.1'endendend
end
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2. NSDataAsset
升級XC10和S.2之前，項目里面有些對 'NSDataAsset' 的錯誤使用： 用‘NSDataAsset’讀ImageAsset中的圖片，這個是不正確的，但是卻可以工作，這次升級修復了這個BUG。
正確的做法使用'DataAsset'，然后才可以用‘NSDataAsset’讀取數據，我由于不夠認真且經驗不足還以為是個BUG，給Apple提了個BUG。。。[捂臉]
3. 第三方庫的重命名 typealias
為了方便的適配S4.2對UIKit中的重命名，有些第三方使用typealias對一些類型進行了重命名，以 RxSwift 為例子，RxSwift中就有如下代碼：
public typealias UIControlEvents = UIControl.Event private
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這會導致一些重命名的類型即使不改也不會報錯，但是一旦去掉了對某個庫的依賴就會引入新的問題。
4.Delegate 的 Access Modifier
在升級S4.2過程中，XC偶爾會提示需要給某些Delegate方法添加 private修飾符，不要為了消除這個??添加private，可能會導致Delegate永遠不被調到；另外，如果是一個public或者open的class，協議方法記得也要加上public，否則會出一樣的問題，具體原因我還在測試，但是現象是這樣的，有新的見解歡迎評論區討論。
5. 機型適配問題，iPhone XS Max字體變大
有些同事遇到XC9構建的安裝包在iPhone XS Max上會有字體變大的情況，這個貌似是普遍現象，微信也有，使用XC10構建安裝包可以解決這個問題，但是會遇到問題6
###6. iOS9.3以下系統Crash率飆升 使用XC10構建安裝包可以解決問題5，但是iOS9.3以下的系統Crash到讓你懷疑人生
以下是2018年9月18日內容
AVAudioSession.sharedInstance().setCategory()
disappeared
Swift 4.2 中 iOS10以下不能用 AVAudioSession.sharedInstance() setCategory
可選方案:
- 使用OC實現該部分，然后使用Swift調用
- 放棄 iOS9用戶體驗
參考地址
do {if #available(iOS 11.0, *) {try audioSession.setCategory(.playback, mode: .default, policy: .longForm, options: [])} else if #available(iOS 10.0, *) {try audioSession.setCategory(.playback, mode: .default, options: [])} else {// Compiler error: 'setCategory' is unavailable in Swifttry audioSession.setCategory(AVAudioSession.Category.playback)}
} catch let error {print("Unable to configure audio sesson category: \(error)")
}
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NSUnderlineStyle(.patternSolid、.none)
disappeared
可選方案:
Wrong: mutableAttributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: [], range: range) Right: mutableAttributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: 0, range: range)
下面是Rename操作
UIKit
#Swift4/UIKit
UITableViewCell
| Swift 4 | Swift 4.2 |
|---|
| UITableViewCellStyle | UITableViewCell.CellStyle |
UIEvent
| Swift 4 | Swift 4.2 |
|---|
| UIEventSubtype | UIEvent.EventSubtype |
UITableView
| Swift 4 | Swift 4.2 |
|---|
| UITableViewScrollPosition | UITableView.ScrollPosition |
| UITableViewAutomaticDimension | UITableView.automaticDimension |
| UITableViewCellEditingStyle | UITableViewCell.EditingStyle |
| UITableViewRowAnimation | UITableView.RowAnimation |
| UITableViewStyle | UITableView.Style |
| UITableViewCellAccessoryType | UITableViewCell.AccessoryType |
UIControl
| Swift 4 | Swift 4.2 |
|---|
| UIControlEvents | UIControl.Event |
UIWindow
| Swift 4 | Swift 4.2 |
|---|
| UIWindowLevelAlert | UIWindow.Level.alert |
| UIKeyboardFrameEndUserInfoKey | UIResponder.keyboardFrameEndUserInfoKey |
| UIKeyboardFrameBeginUserInfoKey | UIResponder.keyboardFrameBeginUserInfoKey |
| UIKeyboardAnimationDurationUserInfoKey | UIResponder.keyboardAnimationDurationUserInfoKey |
| UIKeyboardAnimationCurveUserInfoKey | UIResponder.keyboardAnimationCurveUserInfoKey |
| UIKeyboardIsLocalUserInfoKey | UIResponder.keyboardIsLocalUserInfoKey |
| UIWindowDidBecomeVisible | UIWindow.didBecomeVisibleNotification |
| UIWindowDidBecomeHidden | UIWindow.didBecomeHiddenNotification |
| UIWindowDidBecomeKey | UIWindow.didBecomeKeyNotification |
| UIWindowDidResignKey | UIWindow.didResignKeyNotification |
| UIKeyboardWillShow | UIResponder.keyboardWillShowNotification |
| UIKeyboardDidShow | UIResponder.keyboardDidShowNotification |
| UIKeyboardWillHide | UIResponder.keyboardWillHideNotification |
| UIKeyboardDidHide | UIResponder.keyboardDidHideNotification |
UIViewController
| Swift 4 | Swift 4.2 |
|---|
| open func addChildViewController(_ childController: UIViewController) | open func addChild(_ childController: UIViewController) |
| open func willMove(toParentViewController parent: UIViewController?) | open func willMove(toParent parent: UIViewController?) |
| open func didMove(toParentViewController parent: UIViewController?) | open func didMove(toParent parent: UIViewController?) |
| open func removeFromParentViewController() | open func removeFromParent() |
UIActivity
| Swift 4 | Swift 4.2 |
|---|
| UIActivityType | UIActivity.ActivityType |
UIActivityIndicatorView
| Swift 4 | Swift 4.2 |
|---|
| activityIndicator.activityIndicatorViewStyle | activityIndicator.style |
UIAlertController
| Swift 4 | Swift 4.2 |
|---|
| UIAlertActionStyle | UIAlertAction.Style |
| UIAlertControllerStyle | UIAlertController.Style |
UIPageViewController
| Swift 4 | Swift 4.2 |
|---|
| UIPageViewControllerNavigationDirection | UIPageViewController.NavigationDirection |
| UIPageViewControllerSpineLocation | UIPageViewController.SpineLocation |
| UIPageViewControllerNavigationOrientation | UIPageViewController.NavigationOrientation |
| UIPageViewControllerTransitionStyle | UIPageViewController.TransitionStyle |
| UIPageViewControllerOptionsKey | UIPageViewController.OptionsKey |
UINavigationController
| Swift 4 | Swift 4.2 |
|---|
| UINavigationControllerOperation | UINavigationController.Operation |
UIGestureRecognizer
| Swift 4 | Swift 4.2 |
|---|
| UIGestureRecognizerStatePossible | UIGestureRecognizer.State.possible |
| UIGestureRecognizerStateBegan | UIGestureRecognizer.State.began |
| UIGestureRecognizerStateChanged | UIGestureRecognizer.State.changed |
| UIGestureRecognizerStateEnded | UIGestureRecognizer.State.ended |
| UIGestureRecognizerStateCancelled | UIGestureRecognizer.State.cancelled |
| UIGestureRecognizerStateFailed | UIGestureRecognizer.State.failed |
| UIGestureRecognizerStateRecognized | UIGestureRecognizer.State.recognized |
NSLayoutFormat
| Swift 4 | Swift 4.2 |
|---|
| NSLayoutFormatOptions | NSLayoutConstraint.FormatOptions |
UIEdgeInsets
| Swift 4 | Swift 4.2 |
|---|
| public func UIEdgeInsetsMake(_ top: CGFloat, _ left: CGFloat, _ bottom: CGFloat, _ right: CGFloat) -> UIEdgeInsets | UIEdgeInsets(top: CGFloat, left: CGFloat, bottom: CGFloat, right: CGFloat) |
| public func UIEdgeInsetsInsetRect(_ rect: CGRect, _ insets: UIEdgeInsets) -> CGRect | public func inset(by insets: UIEdgeInsets) -> CGRect |
UIFontDescriptor
| Swift 4 | Swift 4.2 |
|---|
| UIFontDescriptorSymbolicTraits | UIFontDescriptor.SymbolicTraits |
UIImage
| Swift 4 | Swift 4.2 |
|---|
UIKIT_EXTERN NSData * __nullable UIImagePNGRepresentation(UIImage * __nonnull image); | public func pngData() -> Data? |
NSData * __nullable UIImageJPEGRepresentation(UIImage * __nonnull image, CGFloat compressionQuality); | public func jpegData(compressionQuality: CGFloat) -> Data? |
UIApplication
| Swift 4 | Swift 4.2 |
|---|
| UIApplicationDidEnterBackground | UIApplication.didEnterBackgroundNotification |
| UIApplicationWillEnterForeground | UIApplication.willEnterForegroundNotification |
| UIApplicationDidFinishLaunching | UIApplication.didFinishLaunchingNotification |
| UIApplicationDidBecomeActive | UIApplication.didBecomeActiveNotification |
| UIApplicationWillResignActive | UIApplication.willResignActiveNotification |
| UIApplicationDidReceiveMemoryWarning | UIApplication.didReceiveMemoryWarningNotification |
| UIApplicationWillTerminate | UIApplication.willTerminateNotification |
| UIApplicationSignificantTimeChange | UIApplication.significantTimeChangeNotification |
| UIApplicationWillChangeStatusBarOrientation | UIApplication.willChangeStatusBarOrientationNotification |
| UIApplicationDidChangeStatusBarOrientation | UIApplication.didChangeStatusBarOrientationNotification |
| UIApplicationDidChangeStatusBarFrame | UIApplication.didChangeStatusBarFrameNotification |
| UIApplicationBackgroundRefreshStatusDidChange | UIApplication.backgroundRefreshStatusDidChangeNotification |
| UIApplicationProtectedDataWillBecomeUnavailable | UIApplication.protectedDataWillBecomeUnavailableNotification |
| UIApplicationProtectedDataDidBecomeAvailable | UIApplication.protectedDataDidBecomeAvailableNotification |
| UIApplicationUserDidTakeScreenshot | UIApplication.userDidTakeScreenshotNotification |
| UIApplicationOpenSettingsURLString | UIApplication.openSettingsURLString |
| UIApplicationLaunchOptionsKey | UIApplication.LaunchOptionsKey |
| UIInterfaceOrientationIsLandscape() | UIApplication.shared.statusBarOrientation.isLandscape |
UIView
| Swift 4 | Swift 4.2 |
|---|
func bringSubview(toFront view: UIView) | func bringSubviewToFront(_ view: UIView) |
| UIViewAnimationOptions | UIView.AnimationOptions() |
Foundation
NSAttributedString
| Swift 4 | Swift 4.2 |
|---|
| NSAttributedStringKey | NSAttributedString.Key |
QuartzCore
CAShapeLayer
| Swift 4 | Swift 4.2 |
|---|
| kCALineCapRound | CAShapeLayerLineCap.round |
| kCALineCapButt | CAShapeLayerLineCap.butt |
| kCALineCapSquare | CAShapeLayerLineCap.square |
| kCALineJoinMiter | CAShapeLayerLineJoin.miter |
| kCALineJoinRound | CAShapeLayerLineJoin.round |
| kCALineJoinBevel | CAShapeLayerLineJoin.bevel |
| kCAFillRuleNonZero | CAShapeLayerFillRule.nonZero |
| kCAFillRuleEvenOdd | CAShapeLayerFillRule.evenOdd |
參考資料
Swift-Migration-4.2
