HarmonyOS 关于动态设置组件宽度的问题

import window from '@ohos.window';  
import { BusinessError } from '@ohos.base';  
  
@Entry  
@Component  
struct Width {  
  @State message: string = 'Hello World';  
  @State number:number=0;  
  getWidth(){  
    let windowClass: window.Window | undefined = undefined;  
    try {  
      window.getLastWindow(getContext(), (err: BusinessError, data) => {  
        const errCode: number = err.code;  
        if (errCode) {  
          console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(err));  
        }  
        windowClass = data;  
        let windowWidth:number=windowClass.getWindowProperties().windowRect.width  
  
        this.number= px2vp(windowWidth)  
        console.log(this.number+" oooooo")  
        console.log(JSON.stringify(windowWidth))  
        console.info('Succeeded in obtaining the top window. Data: ' + JSON.stringify(data));  
      });  
    } catch (exception) {  
      console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(exception));  
    }  
  }  
  
  aboutToAppear(): void {  
    this.getWidth()  
  }  
  
  build() {  
    Row() {  
      Column() {  
        Text(this.message)  
          .fontSize(50)  
          .fontWeight(FontWeight.Bold)  
      }  
      .width('100%')  
    }  
    .height('100%')  
    .width(this.number)  
  }  
}