编辑导读：iOS是运行于iPhone、iPad和iPod touch设备上、最常用的移动操作系统之一。作为互联网应用的开发者、产品经理、体验设计师，都应当理解并熟悉平台的设计规范。这有利于提高我们的工作效率，保证用户良好的体验。本文是iOS设计规范系列第一篇。

一、3大设计主旨（Design Themes）

iOS与其他平台区分的三个主要主旨：

1. Clarity（清晰）

在整个系统中，文字在各种尺寸上都清晰可辨；

图标精确而清晰，装饰巧妙且恰当，并且对功能的敏锐关注激发了设计；

负空间，颜色，字体，图形和界面元素巧妙地突出重要内容并传达交互性。

2. Deference（遵从）

流畅的动作和清晰美观的界面在帮助人们理解并与内容互动的同时，还能不与之竞争；内容通常填满整个屏幕，半透明和模糊通常暗示更多；

尽量少的使用边框，渐变和阴影可使界面轻量，同时确保内容至关重要。

3. Depth（层次）

清晰的视觉层和逼真的动作传达层次，赋予活力，促进理解；

触摸和可发现性提高了乐趣，并能够访问功能和附加内容而不会丢失上下文；

过渡可以在您浏览内容时提供深度感。

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.

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.

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.

二、6大设计原则（Design Principles）

为了最大限度地提高影响力和覆盖面，请在设计APP时遵循以下6个原则。

1. Aesthetic Integrity（完整性）

审美完整性体现了app的外观和行为与其功能的整合程度。

例如，一个帮助用户执行严肃任务的app可以通过使用微妙、不显眼的图形、标准控件和可预测的行为来保持他们的专注。

另一方面，沉浸式app，如游戏，可以提供吸引人的外观，传递乐趣和刺激感，同时鼓励发现。

2. Consistency（一致性）

一个一致的app通过使用系统提供的界面元素、众所周知的图标、标准文本样式和统一术语来实现熟悉的标准和范例。

这种app符合用户期望的特征和行为。

3. Direct Manipulation（直接性）

对屏幕内容的直接操作会吸引用户并促进理解。

当用户旋转设备使用手势触动屏幕内容时会体验到直接操作。

通过直接操纵，用户可以看到他们行动的直接、可见的结果。

4. Feedback（反馈感)

反馈对用户的行动进行了确认，并显示行动结果以使用户了解情况。

内置的iOS app为用户的每一项操作提供可感知的反馈。

轻触时会突出显示交互元素；进度指示器会传达长时间运行的项目的状态；动画和音效有助于阐明操作的结果。

5. Metaphors（隐喻性）

当一个app的虚拟对象和动作都是对熟悉事物的隐喻时（不管基于现实世界还是数字世界），用户学习的更快

隐喻在iOS系统中发挥的很好，因为用户是直接与屏幕产生物理交互的。

用户移动视图来查看更多的内容；拖拽内容；切换开关、移动滑块并且直接滚动来选取值；甚至可以像翻书或杂志一样轻快翻页。

6. User Control（控制感）

在整个iOS中，用户是掌控者，而不是APP。

APP可以建议一个行动方案或警告危险后果，但APP接管决策通常是一个错误。

好的APP可以在用户授权和避免不必要的结果之间找到正确的平衡。

APP可以通过保持交互元素熟悉和可预测，确认破坏性操作以及轻松取消操作（即使它们已经在进行中）来使用户感觉自己在控制。

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.

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.

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.

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. Interactiveelements are highlighted briefly when tapped, progress indicators communicate the status of long-running operations, and animation and sound help clarify the results of actions.

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.

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.

参考资料：

Apple Developer-Human Interface Guidelines.

#专栏作家#

晓吾，微信公众号：体验主义，人人都是产品经理专栏作家。腾讯高级交互设计师，前创新工场、新浪微博交互设计师。专注社交创新与娱乐产品设计。

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