IOS Human Interface Guidelines (Original translation) Chapter 3, iosguidelines

IOS Human Interface Guidelines (Original translation) Chapter 3, iosguidelines

Adaptation and Layout

· Creation adaptation

Generally, people want to use their favorite apps on all their devices, regardless of the device's targeting. In iOS8 and later versions, you can use the size class and automatic layout to define the screen layout when the device placement environment changes, how should the View Controller and view be adjusted to help you meet this expectation. The concept of environment placement may involve the entire screen or only part of the screen, such as a pop-up menu area or a main view in a separated View Controller.

IOS defines two types of dimensions: Regular and compact. The general dimension class is associated with the loose space, and the compact dimension class is associated with the limited space. To describe a placement environment, you need to specify a horizontal dimension class and a vertical (vertical) dimension class. As you guessed, an iOS device can use a series of dimension classes for vertical orientation and a different series of dimension classes for horizontal orientation.

When the size of a placement environment changes, iOS can automatically generate various layout changes. For example, when the vertical dimension class changes from compact to normal, the navigation bar and toolbar automatically increase.

When you rely on the dimension class to control changes in the layout, your app can look great in any placement environment. To learn how to use the dimension class in Interface Builder, see the dimensional class design guide. Note: In a dimension class, make sure to use automatic layout to make small adjustments to the layout, such as stretching content or compressing content.

The following example shows how the dimension class describes the placement environment of different devices. For example, the iPad uses the regular size class in terms of length, width, and orientation. In other words, the placement environment of the iPad is always horizontal and vertical.

The iPhone's placement environment may change, depending on the device type and how it is targeted.

In vertical placement, iPone6 Plus uses a compact horizontal dimension class and a compact vertical dimension class. In a horizontal placement environment, the iPhone 6 Plus uses a regular horizontal dimension class and a compact vertical dimension class.

All other iPhone models, including iPhone 6, use the same series of dimensions.

In a vertical environment, both iPhone 6, iPhone 5, and iPhone 4S use a compact horizontal dimension class and a conventional vertical dimension class. In a horizontal placement environment, both horizontal and vertical devices use compact dimension classes.

· Provides an excellent experience in every environment

When using adaptability, you can make sure that your UI responds appropriately to changes in the placement environment. Following these guidelines gives users an excellent experience on all devices and targeting.

· Keep your focus on the main content in all environments. This is your top priority. People use your app to browse and interact with the content they are interested in. Changing your focus when the placement environment changes will confuse users and make them feel that they have lost control of the app.

· Avoid unnecessary layout changes. When people rotate devices or run your app on a different device, similar experience in all environments can keep people in their usage patterns (behavior habits ?). For example, if you use a grid in a standard horizontal environment to display images, even if you have to adjust the grid dimension, however, you do not need to use a list in a horizontally compact environment to display the same information.

· Directly tell the user that your app can only run in a targeted manner. People want to use your app in different targeting situations. It is best if you can satisfy this desire. However, if your app can only run in a targeted manner, you should:

· Avoid placing the UI elements that tell people to rotate devices. Running on the supported orientation clearly tells the user to rotate the device. If necessary, do not add unnecessary decoration on the UI.

· Supports targeted variants. For example, if an app can only run horizontally, whether the Home Key is holding the device on the left or right, people should be able to use it. And if people rotate the device 180 degrees when using the app, if the app content can also rotate 180 degrees for response, it would be best.

· If your app explains changes in device orientation when users enter (there are many forms of input), then the app will process device rotation in a specific way. For example, a game that allows people to move content in a game by rotating devices cannot respond to device rotation by rotating the screen. In such a case, you should load all variants as required, and allow people to switch between different variants before the app director starts. Once people start to charge services, they begin to respond to device movements in app-specific ways.

· Use layout to communicate

The layout not only contains how the UI elements are displayed on an app screen. In your layout, you can show users what is most important, what their choices are and how things are related.

· It is easy to focus on directors by improving important content or functions. A good way to achieve this principle is to place important things on the top of the screen-and follow the left-to-right convention-close to the left of the screen.

· Use visual effects and balance to show users the relative importance of elements on the screen. Big things attract attention and tend to look more important than small objects. Big things are also very convenient for users to touch, which makes them particularly useful in some apps-such as Phone and Clock-users often use these apps in an easily distracted environment.

· Simplify browsing and communicate the grouping and system with consortium. Alignment tends to make an app look neat and organized. When the user scrolls the information on a screen, alignment can also give the user space to focus on the content. The indentation and alignment of different information groups indicate how the groups are associated, and it is easier for users to find specific things.

· Ensure that the main content can be understood by the user in the default size. For example, users should not have to scroll horizontally to read important texts or zoom in to see important images.

· Change the font size. Users want most apps to respond appropriately when they select a different font size in their settings. To adapt to some font size changes, you may need to change the layout. To obtain