Animation

Beautiful, subtle animation throughout iOS builds a visual sense of connection between people and content onscreen. When used appropriately, animation can convey status, provide feedback, enhance the sense of direct manipulation, and help users visualize the results of their actions.

漂亮，微妙的动画贯穿iOS建立了一个在用户和屏幕内容之前的联系。当使用恰当，动画可以传递状态，提供反馈，增强直接操作的感受，帮助用户操作结果的可视化。

Use animation and motion effects judiciously.Don’t use animation for the sake of using animation. Excessive or gratuitous animation can make people feel disconnected or distracted, especially in apps that don’t provide an immersive experience. iOS uses motion effects, such as a parallax effect, to create the perception of depth on the Home screen and in other areas. These effects can increase understanding and enjoyment, but overusing them can make an app feel disorienting and difficult to control. If you implement motion effects, always test the results to make sure they work well.

明智地使用动画和动作效果。不要为了动画使用动画。过渡或者无理由的动画会使用户觉得失去连接或者心烦意乱，特别是在那些不提供沉浸式体验的app。iOS使用动作效果，例如一个视差效果，来在主屏幕和其他区域创建一个深度感觉。这些效果可以增强理解和乐趣，但是过度使用它们会使一个app看起来迷惑和难以控制。如果你实现一个动作效果，记得测试结果来确保它们效果不错。

Strive for realism and credibility.People tend to accept artistic license, but they can feel disoriented when movement doesn’t make sense or appears to defy physical laws. If someone reveals a view by sliding it down from the top of the screen, for example, they should be able dismiss the view by sliding it back up.

追求现实和可信。用户倾向于接受艺术效果，但是当动作没有意义或者看起来违背物理法则。如果某人通过从屏幕顶部向下滑打开一个视图，他们应该可以通过上滑来解散这个视图。

Use consistent animation.A familiar, flowing experience keeps users engaged. They're accustomed to the subtle animation used throughout iOS, such as smooth transitions, fluid changes in device orientation, and physics-based scrolling. Unless you’re creating an immersive experience, such as a game, custom animation should be comparable to the built-in animations.

使用一致的动画。一个熟悉的，一致的体验能够留住用户。他们习惯于使用贯穿于iOS的微妙的动画，例如流畅地转场，流畅地改变设备方向，基于物理的滚动。除非你在创建一个沉浸式体验，例如一个游戏，定制动画应该与内置的动画协调。

Make animations optional.When the option to reduce motion is enabled in accessibility preferences, your app should minimize or eliminate application animations.

使动画可选。当可纺性偏好设置减少动画激活时，你的app应该减少或者消除应用的动画。