HarmonyOS preview模拟器运行时，display.getDefaultDisplaySync()获取的宽高为0

import display from '@ohos.display'; 
 
@Entry 
@Component 
struct Index { 
  @State iWidth:number = 0 
  @State iHeight:number = 0 
 
  @State message: string = 'Hello World'; 
 
  aboutToAppear(): void { 
    let displayClass: display.Display | null = null; 
    try { 
      displayClass = display.getDefaultDisplaySync(); 
      this.iWidth = px2vp(displayClass.width) 
      this.iHeight = px2vp(displayClass.height ) 
      // this.iWidth = 300 
      // this.iHeight = 600 
      console.log('display:',displayClass.width,displayClass.height) 
    } catch (exception) { 
      console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception)); 
    } 
  } 
 
  build() { 
    Row() { 
      Column() { 
        Text(this.message) 
          .fontSize(50) 
          .fontWeight(FontWeight.Bold) 
      } 
      .backgroundColor(Color.Blue) 
      .width(this.iWidth) 
      .height(this.iHeight) 
    } 
    .width(this.iWidth) 
    .height(this.iHeight) 
  } 
}