如何获取状态栏和导航栏高度

// MainAbility.ts 
import window from '@ohos.window'; 
import common from '@ohos.app.ability.common'; 
import UIAbility from '@ohos.app.ability.UIAbility'; 
/** 
 * 获取系统状态栏，导航栏高度 
 * @param context 
 * @returns  
 */ 
async function getWindowAvoidArea(context: common.UIAbilityContext): Promise<window.AvoidArea> { 
  try { 
    const mainWindow = await window.getLastWindow(context); 
    const avoidAreaType = window.AvoidAreaType.TYPE_SYSTEM; // 系统默认区域，包括状态栏，导航栏 
    const avoidArea = mainWindow.getWindowAvoidArea(avoidAreaType); 
    return avoidArea 
  } catch (e) { 
    console.log('getWindowAvoidArea fail'); 
    return null 
  } 
} 
 
export default class MainAbility extends UIAbility { 
  // do something 
  async onWindowStageCreate(windowStage: window.WindowStage) { 
    getWindowAvoidArea(this.context); 
    windowStage.loadContent('pages/index') 
  } 
  // do something 
}