scope of this book
总概：
- 第一部分：view， iOS app 的界面基本单位.我们能看见，能touch.让用户与app交互.解释view 的创建，组织，draw(绘制),layered(层级), 动画，和被触碰.
- 第二部分：解释viewController. 可能是最值得注意和重要的特征在iOS编程中.vc让views 能在一个windon中展示.也描述了Cocoa framework提供的每一种view.
- 第三部分：总结了最重要的iOS提供的framework.sound,video,user libraries,mail,maps,device sensors(传感器).
- 第四部分：files, networking, threading, and how to implement undo.
- 附录A：总结很重要的发送到app delegate上的生命周期时间消息.
- 附录B：分类一些有用的可以共用的swift使用的功能.这个需要注意.
有些区域没有完整讲解，只是大概的描述：
- OpenGL
一个开源的c语言的library，作用于：drawing,3d drawing,takes full advantage of graphics hardware.可能是最有效率的方式去draw(绘制),尤其是涉及到动画.iOS 组成了一个简单的OpenGL 版本，称为 OpenGL ES.(Apple's OpenGL Programming Guide for iOS这个里面有详解). OpenGL 界面配置，texture loading, shading, calculation are 简化使用在 GLKit framework.（see the GLKit Framework Reference）.TheMetalandMetal KitandModel I/Oclasses allow you to increase efficincy and performance. - Sprite Kit
Sprite Kit 提供一个内置的框架，作用是涉及2d 的动画游戏. - Scene Kit
macOS 的一部分，使用它可以方便的构建3d游戏和图形交互. - Gameplay Kit
提供写一个游戏app的基础 - Accelerate
- Game Kit
- Advertising
- Newsstand
- Printing
- Security
- Accessibility
- Telephone
- Pass Kit
- Health Kit
- External accessories
- Handoff
- Spotlight
- Siri Kit
New in iOS10(see the SiriKit Programming Guide)
**conventions used **
<i>Italic</i>
Indicates new terms, URLs, email addresses, filenames, and file extensions.
Constant width
Used for program listings, as well as within paragraphs to refer to program ele‐ments such as variable or function names, databases, data types, environmentvariables, statements, and keywords.
Constant width bold
Shows commands or other text that should be typed literally by the user.
Constant width italic
Shows text that should be replaced with user-supplied values or by values deter‐mined by context.
