[null,null,["最后更新时间 (UTC)：2025-07-26。"],[[["\u003cp\u003eIn-car notifications prioritize safety by limiting quantity and content to minimize driver distraction, focusing on crucial information like the notification type and sender.\u003c/p\u003e\n"],["\u003cp\u003eInteractions with notifications are simplified, with shorter display times and basic actions, to ensure drivers can quickly refocus on the road.\u003c/p\u003e\n"],["\u003cp\u003eMessage notifications in cars enable hands-free interaction through play and mute conversation features, allowing drivers to manage messages without visual distraction.\u003c/p\u003e\n"],["\u003cp\u003eThe car's driving state influences notification behavior, with content and interactions adjusted based on whether the car is parked, idling, or moving.\u003c/p\u003e\n"],["\u003cp\u003eCar manufacturers have specialized controls and categories for managing notifications, including options to suppress navigation HUNs and prioritize critical car-related alerts.\u003c/p\u003e\n"]]],[],null,["# Differences: car vs phone\n\n\u003cbr /\u003e\n\nThe need to keep a driver's attention on the road imposes some special requirements on notifications in cars, compared to other devices\n\nNotifications in cars serve the same general purpose as notifications on other devices: communicating a small amount of timely, relevant information from the system or from an app. However, in-car notification systems must be designed differently to minimize distractions for drivers. \n[How notifications differ in cars\nOverview of differences for developers](https://developer.android.com/training/cars/notifications#how-notifications-differ)\n\n*** ** * ** ***\n\nFewer notifications\n-------------------\n\nTo minimize driver distraction, heads-up notifications (HUNs) in a car have tighter limitations compared to other devices.\n\nHUNs in the car should be actionable and time-sensitive, with an importance level of HIGH or above, and they also must meet one or more of the following criteria:\n\n- Safety-critical\n- Driving-relevant\n- Communications-related\n\nNotifications that appear in the Notification Center are mostly the same as on other devices, with a few categories excluded because they are handled elsewhere or are of low importance. For details of how various categories are handled, visit [How car notifications work](/cars/design/automotive-os/product-experience/system-ui/notifications/how-car-notifications-work). \n[Android notifications -- Settings\nMaterial Design discussion of notification channels and importance levels on phones and other devices](https://material.io/design/platform-guidance/android-notifications.html#settings)\n\n*** ** * ** ***\n\nLess content per notification\n-----------------------------\n\nTo allow drivers to glance quickly at notifications and return their eyes to the road, notifications in the car need to focus on only the most essential, easy-to-grasp information.\n\nOur testing has shown that the information most important to drivers is *what* and *who*: What the notification is (message, call, navigation instructions, and so on), and who it is from. HUNs in the car emphasize these elements, along with a simple set of possible actions.\n\n*** ** * ** ***\n\nSimpler interactions\n--------------------\n\nTo minimize distraction, notifications in the car do not include complex contextual controls, such as a long press or controls that are based on the length of the user's swiping action.\n\nAlso, most HUNs appear only briefly, for a default time of 8 seconds, before being automatically dismissed if the user doesn't interact with them. In most such cases, users can deal with the notification later in the Notification Center.\n\nFor details about interactions with HUNs and in the Notification Center, visit [How car notifications work](/cars/design/automotive-os/product-experience/system-ui/notifications/how-car-notifications-work). \n[Notification API changes and restrictions for cars\nTechnical details about notification effects supported differently in cars](https://developer.android.com/training/cars/notifications#api-changes)\n\n*** ** * ** ***\n\nPlayable message notifications\n------------------------------\n\nTo allow drivers to deal with messages easily while paying attention to the road, message notifications in cars should provide the following two capabilities on the notification card:\n\n- **Play:** Reads the notification using either the Assistant or the default TTS (text-to-speech) reader provided by the platform\n- **Mute conversation:** Stops showing HUNs for a specific conversation for the remainder of the drive\n\nIf a conversation is muted, the messages from that conversation will still be available in the Notification Center.\n\n*** ** * ** ***\n\nSimpler Notification Center\n---------------------------\n\nIn cars, the Notification Center (sometimes implemented as a pull-down shade) operates as a temporary holding area for notifications a driver may want to access either during or at the end of the drive. It excludes some categories of notifications, limits the number of notifications shown during a drive, and is cleared at the beginning of each drive.\n\nDetails about what types of notifications appear in the Notification Center are provided in [How car notifications work](/cars/design/automotive-os/product-experience/system-ui/notifications/how-car-notifications-work).\n\n*** ** * ** ***\n\nAwareness of the car's driving state\n------------------------------------\n\nKnowing a car's driving state -- whether it is parked, idling, or moving -- is a crucial factor in deciding how much information can safely be shown to drivers without distracting them.\n\nAndroid Automotive OS includes a UX Restrictions Engine, which is a set of rules (configurable by car makers) about what can and cannot happen during particular driving states. The UX Restrictions Engine allows actions such as the following for notifications, based on driving state (and, optionally, speed ranges):\n\n- Hiding content previews for messages\n- Truncating of text beyond a specified length\n- Limiting the number of list items shown in the Notification Center and elsewhere\n\nThese restrictions can be removed in driving states where they're not needed, such as when the car is parked.\nThe message preview in a notification can be hidden or shown depending on whether the car is moving or not \n[Android Automotive Library\nDriving state additional technical details for developers](https://developer.android.com/reference/android/car/drivingstate/package-summary)\n\n*** ** * ** ***\n\nSpecial categories \\& controls for car makers\n---------------------------------------------\n\nCar makers have the ability to suppress turn-by-turn navigation notifications from appearing as HUNs.\n\nIn addition, Android Automotive OS includes three new notification categories controlled by car makers:\n\n- CATEGORY_CAR_EMERGENCY\n- CATEGORY_CAR_WARNING\n- CATEGORY_CAR_INFORMATION\n\nThe CAR_EMERGENCY and CAR_WARNING categories bypass typical ranking mechanisms, so they appear at the top of the list of notifications in the Notification Center.\n| **Note:** These car-specific categories are intended to be used in addition to other mechanisms for communicating car-related information. They are not a substitute for warning lights or other such mechanisms."]]
