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iOS 10 / Swift 3.0 / XCode 8 总结

1,iOS10 新增的privacy settings

iOS10添加了新的权限控制范围 如果你尝试访问这些隐私数据时得到如下错误:

> This app has crashed because it attempted to access privacy-sensitive> data without a usage description.  The app‘s Info.plist must contain> an NSCameraUsageDescription key with a string value explaining to the> user how the app uses this data

因为它企图访问敏感数据时没有在应用程序的Info.plist
设置privacy key 新增的privacy setting如下:

技术分享
privacy setting

2, OS_ACTIVITY_MODE

更新Xcode 8 如果控制台出现enable_level: 0, persist_level: 0, default_ttl: 0, info_ttl: 0, debug_ttl: 0, generate_symptoms: 0enable_oversize: 可通过如下方法设置:

Edit Scheme-> Run -> Arguments, 在Environment Variables里边添加OS_ACTIVITY_MODE = Disable

3,iOS10 layoutIfNeed

iOS10 在一个控件上调用layoutIfNeed是只会单独计算约束,它所约束的控件不会生效,想要达到之前的效果需要在父级控件上调用layoutIfNeed

4, NSDate

Swift3.0会将oc的NSDate转为Data类型,有些操作NSDate的第三方库会闪退

5, Notification

Swift3.0字符串类型的通知常量被定义为struct

static let MyGreatNotification = Notification.Name("MyGreatNotification")// Use site (no change)NotificationCenter.default().post(name: MyController.MyGreatNotification, object: self)‘

6, Zip2Sequence(::) 被移除

在Swift3.0Zip2Sequence(_:_:)方法被替换为zip(_:_:)

7, Range<>.reversed 被移除

在Swift3.0Range<>.reversed方法被移除,被替换为<Collection>[<Range>].indices.reversed().

var array = ["A","B","C","D"]for i in array.indices.reversed() {    print("\(i)")}输出:3 2 1 0

8, Range新增至四种类型

RangeCountableRangeClosedRangeCountableClosedRange

不同的表达式会生成不同的Range

var countableRange = 0..<20 ‘CountableRange(0..<20)‘var countableClosedRange = 0...20 ‘CountableClosedRange(0...20)‘

9, Swift3.0 Collection 新增 index(_:)系列方法

Index的successor(), predecessor(), advancedBy(_:), advancedBy(_:limit:), or distanceTo(_:)方法被移除,这些操作被移动到Collection

myIndex.successor()  =>  myCollection.index(after: myIndex)myIndex.predecessor()  =>  myCollection.index(before: myIndex)myIndex.advance(by: …) => myCollection.index(myIndex, offsetBy: …)

10, iOS10 UIStatusBar过期

如果你需要操作UIStatusBar,在iOS10需要改为

- (UIStatusBarStyle)preferredStatusBarStyle {    return UIStatusBarStyleDefault;}

11, iOS10 UICollectionView 性能优化

在iOS10 UICollectionView 最大的改变是增加了Pre-Fetching(预加载),
如果你翻看UICollectionView的最新API你可以发现新增了如下属性:

@property (nonatomic, weak, nullable) id<UICollectionViewDataSourcePrefetching> prefetchDataSource @property (nonatomic, getter=isPrefetchingEnabled) BOOL

在iOS10 Pre-Fetching 是默认开启的,如果出于某些原因你不想开启Pre-Fetching,可以通过如下设置禁用:

collectionView.isPrefetchingEnabled = false

UICollectionViewDataSourcePrefetching协议定义如下:

@protocol UICollectionViewDataSourcePrefetching <NSObject>@required// indexPaths are ordered ascending by geometric distance from the collection view- (void)collectionView:(UICollectionView *)collectionView prefetchItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths NS_AVAILABLE_IOS(10_0);@optional// indexPaths that previously were considered as candidates for pre-fetching, but were not actually used; may be a subset of the previous call to -collectionView:prefetchItemsAtIndexPaths:- (void)collectionView:(UICollectionView *)collectionView cancelPrefetchingForItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths  NS_AVAILABLE_IOS(10_0);@end

12, iOS10 UITableView 性能优化

和UICollectionView一样UITableView也增加了Pre-Fetching技术,UITableView新增了如下属性:

@property (nonatomic, weak) id<UITableViewDataSourcePrefetching> prefetchDataSource NS_AVAILABLE_IOS(10_0);

奇怪的是UITableView并没有找到isPrefetchingEnabled属性的定义

13,iOS10 UIScrollView 新增 refreshControl 属性

UIScrollView新增了refreshControl属性

@property (nonatomic, strong, nullable) UIRefreshControl *refreshControl NS_AVAILABLE_IOS(10_0) __TVOS_PROHIBITED;

这意味着UICollectionView和UITableView都支持refresh功能了。

我们也可以脱离UITableViewController使用UIRefreshControl了。

14, Swif3.0 新增作用域访问级别 fileprivate

目前有如下访问级别:

  • 公开(public)
  • 内部(internal)
  • 文件外私有(fileprivate)
  • 私有(private)

15,Swift3.0 允许关键字作为参数标签

Swift3.0开始我们将能使用除inout var let关键字作为参数标签

// Swift 3 calling with argument label:    calculateRevenue(for sales: numberOfCopies,                     in .dollars)    // Swift 3 declaring with argument label:    calculateRevenue(for sales: Int,                     in currency: Currency)    func touchesMatching(phase: NSTouchPhase, in view: NSView?) -> Set<NSTouch>

如果你坚持要使用inout var let关键字可以使用 `` 包裹参数标签

func addParameter(name: String, `inout`: Bool)

iOS 10 / Swift 3.0 / XCode 8 总结