HarmonyOS web再次展示时，会闪一下

参考如下：

import { webview } from '@kit.ArkWeb';
@Entry
@Component
export struct WebPage {
  private webViewController = new webview.WebviewController();
  url = 'https://developer.huawei.com/consumer/cn/doc/harmonyos-faqs-V5/faqs-arkui-67-V5'
  @State visible: boolean = true
  build() {
    NavDestination() {
      Column() {
        Row() {
          Button(`重置初始状态`)
            .fontColor(Color.Black)
            .height('100%')
            .onClick(() => {

              this.webViewController.loadUrl(this.url)
              this.visible = true
            })

          Button(`显示`)
            .fontColor(Color.Black)
            .height('100%')
            .onClick(() => {
              this.visible = true
            })

          Button(`隐藏`)
            .fontColor(Color.Black)
            .height('100%')
            .onClick(() => {
              this.webViewController.loadUrl('about:blank')
              setTimeout(()=>{
                this.visible = false
              },300)

            })
        }
        .width('100%')
        .height(44)
        .margin(44)

        Web({
          src: this.url,
          controller: this.webViewController
        })
          .visibility(this.visible ? Visibility.Visible : Visibility.Hidden)
      }

    }
    .hideTitleBar(true)
  }
}