Design for Notifications The notification system allows users to keep informed about relevant and timely events in your app, such as new chat messages from a friend or a calendar event. Think of notifications as a news channel that alerts the user to important events as they happen or a log that chronicles events while the user is not paying attention - and one that is synced as appropriate across all their Android devices.41591
Anatomy of a notification
This section goes over basic parts of a notification and how they can appear on different types of devices.
Expanded layouts
You have the option to provide more details on notifications. You can use this to show the first few lines of a message or show a larger image preview. This provides the user with additional context, and - in some cases - may allow the user to read a message in its entirety. The user can pinch-zoom or perform a single-finger glide in order to toggle between compact and expanded layouts. For single event notifications, Android provides three expanded layout templates (text, inbox, and image) for you to re-use in your application.
Actions
Android has supported optional actions that are displayed at the bottom of the notification, as far back as Jelly Bean. With actions, users can handle the most common tasks for a particular notification from within the notification shade without having to open the originating application. This speeds up interaction and, in conjunction with "swipe-to-dismiss", helps users to streamline their notification triaging experience.
Be judicious with how many actions you include with a notification. The more actions you include, the more cognitive complexity you create. Limit yourself to the fewest number of actions possible by only including the most imminently important and meaningful ones.
You can specify a maximum of three actions, each consisting of an action icon and an action name. Adding actions to a simple base layout will make the notification expandable, even if the notification doesn't have an expanded layout. Since actions are only shown for expanded notifications and are otherwise hidden, you must make sure that any action a user can invoke from a notification is available from within the associated application as well.
Your notification's main icon will still be shown, so the user can associate it with the icon visible in the status bar.
Navigate to the right place
When the user touches the body of a notification (outside of the action buttons), open your app to the place where the user can view and act upon the data referenced in the notification. In most cases this will be the detail view of a single data item such as a message, but it might also be a summary view if the notification is stacked and references multiple items. If in any of those cases the user is taken to a hierarchy level below your app's top-level, insert navigation into your app's back stack to allow them to navigate to your app's top level using the system back button.
Correctly set and manage notification priority
Starting with Jelly Bean, Android supported a priority flag for notifications. It allows you to
influence where your notification will appear in comparison to other notifications and help to make sure that users always see their most important notifications first.
Summarize your notifications
If your app creates a notification while another of the same type is still pending, avoid creating an altogether new notification object. Instead, turn it into a summary notification for the app.
A summary notification builds a summary description and allows the user to understand how many notifications of a particular kind are pending.
You can provide more detail about the inpidual notifications that make up a summary by using the expanded digest layout. This allows users to gain a better sense of which notifications are pending and if they are interesting enough to be read in detail within the associated app. Android通知的设计英文文献和中文翻译:http://www.751com.cn/fanyi/lunwen_41699.html