As an app designer, you have the opportunity to deliver an extraordinary product that rises to the top of the App Store charts. To do so, you'll need to meet high expectations for quality and functionality.
作为app的设计者， 你有机会提供一个上app商店排行榜的非凡产品。要做到这点，你必须对质量和功能有高的预期。
Three primary themes differentiate iOS from other platforms:
3类基本主题让iOS从其他平台区分出来：
Clarity.Throughout the system, text is legible at every size, icons are precise and lucid, adornments are subtle and appropriate, and a sharpened focus on functionality motivates the design. Negative space, color, fonts, graphics, and interface elements subtly highlight important content and convey interactivity.
清晰：整个系统中任何大小的文本是可辨识的，图标精确易懂，装饰精巧恰当，聚焦于功能都促进设计。留白，颜色，字体，图形和界面元素巧妙的高亮重要内容传达交互。
Deference.Fluid motion and a crisp, beautiful interface help people understand and interact with content while never competing with it. Content typically fills the entire screen, while translucency and blurring often hint at more. Minimal use of bezels, gradients, and drop shadows keep the interface light and airy, while ensuring that content is paramount.
主从：流畅的操作和清爽美观的界面帮助人们理解内容并与之交互但从不跟内容抢眼球。内容通常充满整个屏幕，同时半透明和模糊常常暗示更多。尽少的使用边框，渐变，阴影让界面明亮而轻快，同时确保内容是最重要的。
Depth.Distinct visual layers and realistic motion convey hierarchy, impart vitality, and facilitate understanding. Touch and discoverability heighten delight and enable access to functionality and additional content without losing context. Transitions provide a sense of depth as you navigate through content.
深度：不同的视觉层和逼真的动态传递层级表现生动， 促进了理解。 触摸和易发现增强愉悦感并且在调用功能和其它内容时能够知道前后关系，在你浏览内容时转换提供了一种深度感。
To maximize impact and reach, keep the following principles in mind as you imagine your app’s identity.
在你设想app特性时记住这些原则，最大化这些原则的影响范围。
Aesthetic Integrity
Aesthetic integrity represents how well an app’s appearance and behavior integrate with its function. For example, an app that helps people perform a serious task can keep them focused by using subtle, unobtrusive graphics, standard controls, and predictable behaviors. On the other hand, an immersive app, such as a game, can deliver a captivating appearance that promises fun and excitement, while encouraging discovery.
整体美感
整体美感代表着应用的外观和操作和它的功能结合的多么好。例如，应用帮助用户执行一个重要的任务，通过使用精妙，不突出的图形，标准控件和可预测的行为让他们专注。另一方面，一个沉浸式的应用，如游戏，能够实现一个有魅力的外观来保证有趣刺激，同时激发探索。
Consistency
A consistent app implements familiar standards and paradigms by using system-provided interface elements, well-known icons, standard text styles, and uniform terminology. The app incorporates features and behaviors in ways people expect.
一致性
一致性的应用通过系统提供的界面元素，众所周知的图标，标准的文本样式和统一术语实现常见的标准和模式。应用以用户期望的方式集合特性和行为。
Direct Manipulation
The direct manipulation of onscreen content engages people and facilitates understanding. Users experience direct manipulation when they rotate the device or use gestures to affect onscreen content. Through direct manipulation, they can see the immediate, visible results of their actions.
直接操控
屏幕内容的直接操控吸引用户并促进理解。用户体验直接操控当他们旋转设备或使用手势与屏幕内容交互。通过直接操控，他们能快速，直观的看到行为结果。
Feedback
Feedback acknowledges actions and shows results to keep people informed. The built-in iOS apps provide perceptible feedback in response to every user action. Interactive elements are highlighted briefly when tapped, progress indicators communicate the status of long-running operations, and animation and sound help clarify the results of actions.
反馈
反馈让用户知道确认了操作和显示了结果。iOS内置应用为每个用户操作提供可感知反馈响应。当点击时交互元素简洁的高亮，进度指示长时间运行操作的状态，动效和音效帮助明确操作结果。
Metaphors
People learn more quickly when an app’s virtual objects and actions are metaphors for familiar experiences—whether rooted in the real or digital world. Metaphors work well in iOS because people physically interact with the screen. They move views out of the way to expose content beneath. They drag and swipe content. They toggle switches, move sliders, and scroll through picker values. They even flick through pages of books and magazines.
隐喻
不论是源于真实或数字世界，当应用的虚拟元素或动作是熟悉经验的隐喻，用户学习更快。在iOS隐喻运用的很好，因为用户通过屏幕来物理交流。他们移动视图来显示下面的内容。他们拖拽滑动内容。他们关联切换，移动滑块，滚动选择值。他们甚至轻拂翻书和翻杂志。
User Control
Throughout iOS, people—not apps—are in control. An app can suggest a course of action or warn about dangerous consequences, but it’s usually a mistake for the app to take over the decision-making. The best apps find the correct balance between enabling users and avoiding unwanted outcomes. An app can make people feel like they’re in control by keeping interactive elements familiar and predictable, confirming destructive actions, and making it easy to cancel operations, even when they’re already underway.
用户控制
贯穿iOS，用户而不是应用在控制。应用可以建议操作的方案或警告危险的结果，但取代用户做决定通常是一个错误。优秀的应用能在用户使用和避免不想要的结果之间找到正确的平衡。应用能够通过熟悉可预知元素，确认危险操作，可撤销已进行的操作，让用户感觉应用在他们控制中。
