UI组件怎样条件执行选项函数？

import web_webview from '@ohos.web.webview'; 
 
class MyButtonModifier implements AttributeModifier<ButtonAttribute> { 
  ChangeColor: boolean = false 
  applyNormalAttribute(instance: ButtonAttribute): void { 
    if (this.ChangeColor) { 
      instance.backgroundColor(Color.Red) 
    } 
  } 
} 
class MyWebModifier implements AttributeModifier<WebAttribute> { 
  ChangeWidth: boolean = false 
  applyNormalAttribute(instance: WebAttribute): void { 
    if (this.ChangeWidth) { 
      instance.width(100) 
      instance.height(200) 
    } 
  } 
} 
 
@Entry 
@Component 
struct attributeDemo { 
  @State modifier: MyButtonModifier = new MyButtonModifier() 
  @State webfier: MyWebModifier = new MyWebModifier() 
  webviewController: web_webview.WebviewController = new web_webview.WebviewController(); 
 
  onPageShow(): void { 
    //模拟接口返回或者点击事件改变状态 
    setTimeout(()=>{ 
      this.modifier.ChangeColor = !this.modifier.ChangeColor 
    },1000) 
    setTimeout(()=>{ 
      this.webfier.ChangeWidth = !this.webfier.ChangeWidth 
    },2000) 
  } 
 
 
  build() { 
    Row() { 
      Column() { 
        // web组件加载本地index.html页面 
        Web({ src: $rawfile('index.html'), controller: this.webviewController}) 
          .javaScriptAccess(true) 
          .multiWindowAccess(true) 
          .domStorageAccess(true) 
          .allowWindowOpenMethod(true) 
          .backgroundColor(Color.Green) 
          .attributeModifier(this.webfier) 
 
        Button("Button") 
          .attributeModifier(this.modifier) 
      } 
      .width('100%') 
    } 
    .height('100%') 
  } 
}