全局处理异常,对于发生的js crash进行全局统一管控，存在两点好处。

//EntryAbility.ets 
import AbilityConstant from '@ohos.app.ability.AbilityConstant'; 
import hilog from '@ohos.hilog'; 
import UIAbility from '@ohos.app.ability.UIAbility'; 
import Want from '@ohos.app.ability.Want'; 
import window from '@ohos.window'; 
import errorManager from '@ohos.app.ability.errorManager'; 
 
export default class EntryAbility extends UIAbility { 
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void { 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate'); 
    //创建异常发生时的回调 
    let observer: errorManager.ErrorObserver = { 
      //onUnhandledException回调，回调返回的对象为一个字符串 
      onUnhandledException(errorMsg) { 
        console.log('testTagonUnhandledException, errorMsg: ', errorMsg); 
      }, 
      //onException回调，回调返回的对象是一个包装好的对象，存在一些属性 
      onException(errorObj) { 
        console.log('testTagonException, name: ', errorObj.name); 
        console.log('testTagonException, message: ', errorObj.message); 
        if (typeof(errorObj.stack) === 'string') { 
          console.log('testTagonException, stack: ', errorObj.stack); 
        } 
      } 
      //以上两种回调唯一区别在于回调返回值是否封装为对象，无功能类的区别 
    }; 
    let observerId = -1; 
    //开启监听异常 
    observerId = errorManager.on('error', observer); 
  } 
 
  onDestroy(): void { 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onDestroy'); 
  } 
 
  onWindowStageCreate(windowStage: window.WindowStage): void { 
    // Main window is created, set main page for this ability 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate'); 
 
    windowStage.loadContent('pages/Index', (err, data) => { 
      if (err.code) { 
        hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? ''); 
        return; 
      } 
      hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? ''); 
    }); 
  } 
 
  onWindowStageDestroy(): void { 
    // Main window is destroyed, release UI related resources 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageDestroy'); 
  } 
 
  onForeground(): void { 
    // Ability has brought to foreground 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onForeground'); 
  } 
 
  onBackground(): void { 
    // Ability has back to background 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onBackground'); 
  } 
}