A 页面跳转 B 页面，需要传入扩展方法，让 B 页面在运行时调用，以实现定制 B 页面运行时的效果

//ChildComp.ets 
@Component 
export struct ChildComp { 
  @Builder FunBuilder() {} 
  @BuilderParam aBuilder: () => void = this.FunBuilder; 
 
 
  build(){ 
    Column() { 
      this.aBuilder(); 
    } 
  } 
} 
 
//ParentComp.ets 
import { ChildComp } from './ChildComp'; 
 
@Entry 
@Component 
struct ParentComp { 
  @State message: string = 'Hello World' 
  @Builder componentBuilder() { 
    Text('Parent Builder'); 
  } 
 
  build() { 
    Column() { 
      Column() { 
        Text(this.message) 
          .fontSize(50) 
          .fontWeight(FontWeight.Bold) 
      } 
      .width('100%') 
 
      ChildComp({aBuilder: this.componentBuilder}) 
    } 
    .height('100%') 
  } 
}