MJ

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大多数的iOS应用程序都是通过UIKit框架来完成的，它(UIKit)定义了通用的界面元素组件。该框架保证了应用程序在不同平台的操作一致性，同时提供了高度的定制服务。这些灵活、常用的元素使得你的设计能够完美适配于任何iOS设备，他们甚至能够随系统的更新而自动更新。这些界面元素组件主要包括三类： 

栏。告诉用户他们所处的位置，提供导航。栏里包含能够引导用户和传递信息的按钮或其他元素。

视图。用户在应用里的主要内容阅读区域，比如文字、图片、动画和交互元素。视图能够实现翻转、插入、删除和排列等动能。

控件。能够引导用户或者传递信息。比如按钮、开关、文本区域和进度条等。

为了更好地完成iOS界面的工作，UIKit规定了可使用的功能。通过使用这个框架，应用程序可以响应用户的各种屏幕内操作，比如拖拽、触摸和涂画等。

iOS 整合了其他的程序框架和技术，包括Apple支付、HealthKit和ResearchKit等。这会让你设计出更优秀的手机应用。 

英文原版----------------------------------------------------------------------------

Interface Essentials

Most iOS apps are built using components from UIKit, a programming framework that defines common interface elements. This framework lets apps achieve a consistent appearance across the system, while at the same time offering a high level of customization. UIKit elements are flexible and familiar. They’re adaptable, enabling you to design a single app that looks great on any iOS device, and they automatically update when the system introduces appearance changes. The interface elements provided by UIKit fit into three main categories:

Bars. Tell people where they are in your app, provide navigation, and may contain buttons or other elements for initiating actions and communicating information.

Views. Contain the primary content people see in your app, such as text, graphics, animations, and interactive elements. Views can enable behaviors such as scrolling, insertion, deletion, and arrangement.

Controls. Initiate actions and convey information. Buttons, switches, text fields, and progress indicators are examples of controls.

In addition to defining the interface of iOS, UIKit defines functionality your app can adopt. Through this framework, for example, your app can respond to gestures on the touchscreen and enable features such as drawing, accessibility, and printing.

iOS tightly integrates with other programming frameworks and technologies too, such as Apple Pay, HealthKit, and ResearchKit, enabling you to design amazingly powerful apps. 

原文链接----------------------------------------------------------------------------

https://developer.apple.com/ios/human-interface-guidelines/overview/interface-essentials/