HarmonyOS 全局loading的菊花如何实现？

@Entry  
@Component  
export struct LoadingPage {  
  @Prop flag: boolean;  
  build() {  
    Row() {  
      LoadingProgress().color(Color.White).width(50).height(50)  
    }  
    .height(this.flag ? '100%' : 0)  
    .width('100%')  
    .position({ x: 0, y: 0 })  
    .backgroundColor('#4D000000')  
    .justifyContent(FlexAlign.Center)  
  }  
}

import { LoadingPage } from './LoadingPage'  
@Entry  
@Component  
struct PageThree {  
  @State flag: boolean = false; // 控制是否加载  
  build() {  
    Column() {  
      Button('加载动画').onClick((event: ClickEvent) => {  
        this.flag = !this.flag;  
      })  
      LoadingPage({ flag: this.flag });  
    }  
    .height('100%')  
    .width('100%')  
    .alignItems(HorizontalAlign.Start)  
    .justifyContent(FlexAlign.Start)  
  }  
}