HarmonyOS webview加载html之后，通过this.webviewController.getPageHeight()获取的高度不正确

import webView from '@ohos.web.webview' 
@Entry 
@Component 
struct WebPage { 
  controller: webView.WebviewController = new webView.WebviewController(); 
  aaa:number=0 
  build() { 
    Column() { 
      Web({ src: $rawfile('MainPage.html'), controller: this.controller }) 
        .width('100%') 
        .height('100%') 
        .javaScriptAccess(true) 
        .domStorageAccess(true) 
        .verticalScrollBarAccess(true) 
        .onPageVisible(() => { 
          console.info(`height1>${this.controller.getPageHeight()}`) 
        }) 
    } 
  } 
}