People tend to be unaware of an app’s navigation until it doesn’t meet their expectations. Your job is to implement navigation in a way that supports the structure and purpose of your app without calling attention to itself. Navigation should feel natural and familiar, and shouldn’t dominate the interface or draw focus away from content. In iOS, there are three main styles of navigation.
除非导航不符合他们的预期, 否则在你的应用里用户不太会意识到导航的存在。你的工作就以一种支持APP结构和目的方式来实现，而导航本身不引起关注。导航应该感觉起来自然和谐，不应该主导界面或转移内容的注意力。在iOS中有三种主要的导航风格.
Hierarchical navigation.Make one choice per screen until you reach a destination. To go to another destination, you must retrace your steps or start over from the beginning and make different choices. Settings and Mail use this navigation style.
层级导航，在每个页面做出选择直到到达目的地。到另外一个目的地，用户需要逐级返回或者回到初始层级，再做出不同的选择。系统设置和邮件应用使用这种导航风格。
Flat navigation.Switch between multiple content categories. Music and App Store use this navigation style.
扁平导航，在多种内容类别中切换，音乐和应用商店使用这种导航风格.
Content-driven or experience-driven navigation.Move freely through content, or the content itself defines the navigation. Games, books, and other immersive apps generally use this navigation style.
内容或体验驱动导航。通过内容自由的移动，或则内容自己定义导航。游戏，阅读，还有其它的沉浸式应用通常使用这种风格。
Some apps combine multiple navigation styles. For example, an app that uses flat navigation may implement hierarchical navigation within each category.
一些应用结合多种导航方式。例如，一个应用使用扁平导航，在每个类目可以实现层级导航。
Always provide a clear path.People should always know where they are in your app and how to get to their next destination. Regardless of navigation style, it’s essential that the path through content is logical, predictable, and easy to follow. In general, give people one path to each screen. If they need to see a screen in multiple contexts, consider using an action sheet, alert, popover, or modal view. To learn more, seeAction Sheets,Alerts,Popovers, andModality.
在应用中提供清晰的路径，用户可以知道他们在哪并知道如何进入另一个目的地。忽略导航模式，最重要的是对用户来说路径是有逻辑的，可预测的，并容易遵循的。通常给用户一条路径到达每个界面。如果他们需要在多种情境下看一个界面，可以考虑使用操作表单，弹出框，浮层，模式视图。学习更多查看Action Sheets,Alerts,Popovers, 和 Modality.
Design an information structure that makes it fast and easy to get to content.Organize your information structure in a way that requires a minimum number of taps, swipes, and screens.
设计一种能简洁高效到达内容的信息结构，以最少的点击，滑动和界面来组织你的信息结构。
Use touch gestures to create fluidity.Make it easy to move through your interface with minimum friction. For example, you could let people swipe from the side of the screen to return to the previous screen.
使用触摸手势来创建流。在最小的阻力下，方便容易的到达你想去的界面，列如，你可以让用户侧滑来回到前一个界面。
Use standard navigation components.Whenever possible, use standard navigation controls such as page controls, tab bars, segmented controls, table views, collection views, and split views. Users are already familiar with these controls, and will intuitively know how to get around your app.
使用标准的导航组件。只要可能，使用标准的导航控制，如：页面控制，页签栏，分栏控制，表格视图，集合视图和分离视图。用户已经熟悉了这些控制，能够直觉的知道怎样来玩转你的应用。
Use a navigation bar to traverse a hierarchy of data.The navigation bar’s title can show the current position in the hierarchy, and the back button makes it easy to return to the previous location. For specific guidance, seeNavigation Bars.
使用导航栏让用户访问数据层级。导航栏的标题能显示当前层级位置；返回按钮让用户容易回到前一个层级。需要详细的指导，查阅 Navigation Bar。
Use a tab bar to present peer categories of content or functionality.A tab bar lets people quickly and easily switch between categories, regardless of the current location. For specific guidance, seeTab Bars.
使用标签栏显示当前类似内容或功能的分类。标签栏可以让用户快速容易的切换分类，而不用考虑当前层级位置。需要详细的指导，查阅Tab Bar。
Use a page control when you have multiple pages of the same type of content.A page control clearly communicates the number of pages available and which one is currently active. The Weather app uses a page control to show location-specific weather pages. For specific guidance, seePage Controls.
当你有多个相同类型内容的页面，可以使用页面控制。页面控制清晰地表达了可能的页面数量，并告知当前显示的是哪个。如，天气应用使用页面控制显示当地特定天气页面。需要详细的指导，查阅 Page Control.
Tip：Segmented controls and toolbars don’t enable navigation. Use a segmented control to organize information into different categories. Use a toolbar to provide controls for interacting with the current context. For additional information on these types of elements, seeSegmented ControlsandToolbars.
提示：分栏控制和工具栏不用来导航. 使用分栏控制来组织不同的信息种类。使用工具栏提供控制，跟当前场合发生交互。需要这些元素类型的额外信息，查阅 Segmented Controls 和 Toolbars.
