iOS Design Themes
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.
作为一名app设计师，你有机会提交一个卓越的、在苹果商店购物车中名次靠前的产品。为了做到这一点，你需要满足质量和功能的高期望值。
Three primary themes differentiate iOS from other platforms:
3个IOS不同于其他平台的设计风格：
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。贯穿整个系统，文本在每个尺寸上是易读的，图标准确而易懂的，装饰品精细而恰当，强烈关注功能来驱动设计。实体周围的空间，颜色，字体，图像和界面元素精细地突出重要内容和传达可交互性。
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.
依从。流畅的手势,漂亮的界面帮助人们理解内容，完成与内容的交互，即使人们从没使用过它。覆盖了整个屏幕的是代表性内容，当需要更多内容时通常使用半透明和模糊的方式显示。很少使用斜垫面，而且抛弃阴影保持界面明亮而轻快，只显示最重要内容。
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.
纵深。视觉上的分层和逼真的手势使应用更具活力，有利于理解。在不丢失上下文的情况下，触屏和可见增强用用户的愉悦感,可访问性和功能、额外的内容。过渡效果，让你有种在探索内容深度的体验感。
Design Principles
设计原则
To maximize impact and reach, keep the following principles in mind as you imagine your app’s identity.
为了让你的应用更好，让人印象深刻。记住以下设计原则在你设计app的时候。
Aesthetic Integrity
完整的美学
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.
完整的美学代表有你的app外貌、行为与它的功能集成得有多好。例如，利用精确不唐突的图片，标准控制，可预测的行为一个app帮助用户集中精力解决一个复杂的任务。另一方面，一款沉浸式的app，例如一款游戏，会有拥有一个令人着迷的界面来带给人们乐趣和兴奋，同时鼓励探索。
Consistency
一致性
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.
一款拥有一致性的app通过利用系统提供的界面元素，熟悉的图标，标准的文本风格和统一的术语实现熟悉的标准化和模板。app会按照人们期望的方式组织功能特性和行为。
Direct Manipulation
直接操作
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.
通过触摸技术在屏幕上直接操作内容能够帮助人们理解内容。用户体验直接操作是指当他们旋转设备或用手势去操作屏幕内容。通过直接操作，他们能马上看见他们操作的结果。
Feedback
反馈
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.
反馈保证用户操作之后的结果及时展现。对于任何用户动作，那些内置的iOS apps 提供相应可预测的反馈行为。交互元素被轻敲后会高亮显示，进度条用来表示一个长操作的状态，动画和声音加强操作结果显示效果。
Metaphors
隐喻
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.
当一个app的虚拟对象和动作是隐喻我们日常熟悉的经验时，用户能够学得更快-无论在现实世界和数字世界。隐喻在IOS中表现良好是因为人们是通过物理行为与屏幕交互的。他们移动界面暴露在内容之下。他们拖拽和滑动内容。他们转换开关，移动滑块，滚动选取选项值。他们甚至通过滑动来翻阅书和杂志。
User Control
用户控制
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.
贯穿iOS，用户-而不是apps-会觉得一切尽在掌控。一个app可以给用户操作建议或者警告危险的后果，但让app完全接管决策通常是个错误。最棒的app会在授权用户和避免不想要的结果之间找到最佳平衡。一款app会让用户觉得一切尽在掌握通过使用熟悉和可预测性的交互元素，破坏性操作需要确认，还有让取消操作变得简单，甚至仅当用户在操作起步阶段。
https://developer.apple.com/ios/human-interface-guidelines/overview/design-principles/