| ohos.stationary | on(activity: ActivityType, event: ActivityEvent, reportLatencyNs: number, callback: Callback<ActivityResponse>): void | Subscribes to the device status. This API uses an asynchronous callback to return the result.|
| ohos.stationary | once(activity: ActivityType, callback: Callback<ActivityResponse>): void | Obtains the device status. This API uses an asynchronous callback to return the result.|
| ohos.stationary | off(activity: ActivityType, event: ActivityEvent, callback?: Callback<ActivityResponse>): void | Unsubscribes from the device status. |
## Constraints
The device must support the acceleration sensor.
## How to Develop
1. Subscribe to the event indicating entering the absolute still state, and the event is reported every 1 second.