@zadr 在 iOS 7 正式发布几个小时后在 Twitter 上连续发了一些 iOS 7 SDK 小技巧，大部分都是我还不知道的东西，所以摘录一下，版权归 @zadr 完全所有。

iOS 7: -[AVPlayer volume] and -[AVPlayer muted]; ! You can finally programmatically control the volume of playback without private APIs! via

AVPlayer 音量状态。

iOS 7: [CTTelephonyNetworkInfo currentRadioAccessTechnology]; what kind of cellular connection you’re on now. LTE/GPRS/CDMA{Rev 0, …}/etc! via

获取运营商网络类别。

iOS 7: -[NSArray firstObject]; Like -[NSArray lastObject];, only, the other end of the array. via

NSArray 直接取第一个对象。推荐 Underscore.m.

iOS 7: NSData has base64 encoding/decoding support now. And this fancy method, enumerateByteRangesUsingBlock:. via

NSData 有了原生的 base64 方法 base64EncodedStringWithOptions:。

iOS 7: NSURLComponents: Build a NSURL and have it automatically handle encoding of strings for fragement/path/query/etc. via

NSURLComponents 自动编码处理。

iOS 7: iAd support for prerolls in MPMoviePlayerController. This is more of a heads up than an FYI. via

iAd 支持从前卷广告类型。

iOS 7: JavaScriptCore! Bridge between executing native code and executing JavaScript without needing a UIWebView. via

ObjC 直接操作 JS 的 API，JavaScriptCore 是个里程碑，值得好好学习一番。

iOS 7: MKDistanceFormatter. Localized, unit-specific formatting of distances for both imperial and metric systems. via

MapKit 相关，支持本地化的地点距离换算。

iOS 7: -[MPVolumeView wirelessRouteActive] and -[MPVolumeView wirelessRoutesAvailable] — Customize volume control when AirPlay is available. via

AirPlay 音量控制。

iOS 7: -[UIScrollView keyboardDismissMode]; — Easily recreate Messages.app’s scroll-to-dismiss-keyboard behavior! via

类似系统 Message 的键盘滑动消失效果，UIScrollViewKeyboardDismissModeInteractive.

iOS 7: UITextView supports inserting and tapping on links. Making your own Twitter client just got that much easier! via

UITextView 支持链接点击，应该是 TextKit 带来的新功能。TextKit 也是一个很值得学习的新东西。

iOS 7: AVCaptureDeviceFormat has video zooming with stabilization and simple control over frame rate/duration! via

视频录制支持缩放，以前不支持？

iOS 7: AVSpeechSynthesis - Speak text to users without requiring VoiceOver to be turned on. via

VoiceOver 相关。

iOS 7: Foundation changed a whole bunch of return types to be instancetype instead of id. Yay, type safety! via

默认对象返回类型改为 instancetype，自己封装的类库要跟进。

iOS 7: MediaAccessibility. New framework that makes it really easy to work with closed captions and video. via

图片视频功能继续加强。

iOS 7: MFMessageComposeViewController supports adding attachments! Take a photo/video and iMessage it to someone in the same flow. via

邮件分享支持直接添加附件。

iOS 7: AVCaptureMetadataOutput can detect and decode most kinds of barcodes, including QR codes! via

原生支持二维码扫描！

iOS 7: Also fixed some security vulnerabilities and updated root certificates. Check ‘em out, http://support.apple.com/kb/HT5934 via

修复了一些证书相关的安全问题。

iOS 7: SSReadingList. Add Stuff to Safari’s reading list that syncs between your Mac and iOS devices. via

Safari Reading List API。

iOS 7: I don’t even know how to describe it accurately, but, there’s some amazing motion APIs in there to explore. Can’t call out just one. via

CoreMotion API，M7 也是 iPhone 5s 最吸引我的东西。

iOS 7: UIInputView: If you have a custom input field, use this as the root object. All subviews then get tinting and blur effects. via

iOS 7 输入框的模糊效果。

iOS 7: UISimpleTextPrintFormatter: Print attributed strings without having to fall back to CoreGraphics to render content before printing. via

更为简单的打印内容格式化。

iOS 7: -[NSObject decreaseSize:] / -[NSObject increaseSize:]; // called when cmd+ & cmd- are hit, so you can increase/decrease content size. via

外接键盘可控制显示大小，类似 OS X 上的 Cmd+/Cmd-.

iOS 7: dispatch_source_memorypressure_flags_t, for whenever the system’s memory pressure conditions change. Critical <-> Warn <-> Normal. via

GCD 相关，话说 GCD 的使用一直停留在基本层面，要多多深入。

PS: 分享一个 Twitter 搜索技巧: iOS 7 from:zadr 即可搜索 @zadr 所有包含 iOS 7 关键字的 Tweets。最后鄙视一下一些所谓的开发者，完全无视 NDA 的存在，在 iOS 7 SDK 正式发布前通过翻译等方式来刷自己的技术存在感。