HarmonyOS 如何获取屏幕宽高并设置为全局供所有页面调用？

// EntryAbility.ets  
import display from '@ohos.display'; // 屏幕属性  
let screenHeight: number = 0;  // 保存屏幕高度（px）  
let screenWidth: number = 0;  // 保存屏幕宽度（px）  
export default class EntryAbility extends UIAbility {  
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {  
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');  
  }  
  onWindowStageCreate(windowStage: window.WindowStage): void {  
    // 通过屏幕属性获取屏幕宽高  
    display.getAllDisplays((err,data) => {  
      screenHeight = data[0].height;  
      screenWidth = data[0].width;  
      // 使用AppStorage存储获取的屏幕宽高  
      AppStorage.setOrCreate('globalScreenHeight', screenHeight);  
      AppStorage.setOrCreate('globalScreenWidth', screenWidth);  
      hilog.info(0x0000, 'testTag', `${screenHeight} --- ${screenWidth}`, 'Ability onWindowStageCreate')  
    })  
  }  
  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');  
  }  
}   
// Index.ets  
// 在页面中使用  
@Entry  
@Component  
struct Index {  
  @State screenHeight: number | undefined = AppStorage.get('globalScreenHeight');  
  build() {  
    Column() {  
      Text('屏幕高度：' + this.screenHeight)  
    }  
  }  
}