1# hiTraceMeter 2 3### Introduction 4 5Logging consists of two parts: hiAppEvent for application event logging and hiTraceMeter for performance tracing. 6 7You can call `hiAppEvent` APIs to log various events that occur during application running. 8 9This sample illustrates how to obtain application fault information in eTS. The display effect is as follows: 10 11 12 13### Concepts 14 15hiAppEvent: A module that provides the application event logging functions, such as writing application events to the event file and managing the event logging configuration. 16 17### Required Permissions 18 19N/A 20 21### Usage 22 231. Touch **Write Event**. A message is displayed, indicating that event writing is successful. 24 252. If you turn on the **Disable hiAppEvent** switch and touch **Write Event** again, a message is displayed, indicating that the event writing has failed. 26 273. If you turn off the **Disable hiAppEvent** switch and touch **Write Event** again, a message is displayed, indicating that event writing is successful. 28 29### Constraints 30 311. This sample can only be run on standard-system devices. 32 332. Performance tracing results can be verified only based on the logs obtained by running commands. 34 353. DevEco Studio 3.0 Beta3 (Build version: 3.0.0.901, built on May 30, 2022) must be used. 36
