如何在Flutter中使用BottomNavigationBar维护Webview状态 [英] How to maintain Webview state with BottomNavigationBar in Flutter

问题描述

我正在创建一个Flutter应用程序，该应用程序使用BottomNavigationBar在页面之间进行切换。在其中一页中，我有一个Webview（我使用的是Flutter开发的插件团队），当我导航到另一个标签然后返回时，我无法保持Web视图的状态。我也不知道是否有办法。

I'm creating a Flutter application that uses a BottomNavigationBar to change between pages. In one of the pages, I have a Webview (I'm using the plugin developed by the Flutter dev team) and I can't get to keep the state of the webview when I navigate to another tab then come back. I don't know if there is a way either.

我尝试使用PageStorageBucket以及AutomaticKeepAliveClientMixin都没有用。我注意到，使用PageStorageBucket时，简单的ListView的状态会保留在选项卡之间，但是似乎不适用于Webview。

I've tried using a PageStorageBucket and also AutomaticKeepAliveClientMixin, to no avail. I've noticed that the state of a simple ListView is kept between tabs when using PageStorageBucket, but it doesn't seem to work with a Webview.

可重现的示例：

class _MyHomePageState extends State<MyHomePage> {
  List<Widget> _pages;
  int _selectedIndex = 0;

  @override
  void initState() {
    super.initState();
    _pages = [
      Center(
        child: Text('HOME'),
      ),
      WebView(
        initialUrl: 'https://flutter.io',
        javascriptMode: JavascriptMode.unrestricted,
      )
    ];
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      bottomNavigationBar: BottomNavigationBar(
        items: [
          BottomNavigationBarItem(icon: Icon(Icons.home), title: Text('Home')),
          BottomNavigationBarItem(icon: Icon(Icons.web), title: Text('Web')),
        ],
        currentIndex: _selectedIndex,
        onTap: (index) {
          setState(() {
            _selectedIndex = index;
          });
        },
      ),
      body: _pages[_selectedIndex],
    );
  }

https://imgur.com/qOm7uEa

当我返回时，我希望网络处于相同状态到Webview选项卡，我不希望它重新加载。

I'd want the web to be in the same state when I go back to the Webview tab, I don't want it to reload.

推荐答案

您可以为此使用IndexedStack。它将永远不会卸下孩子们。但是，它会一次全部加载它们[产生一些滞后]

You could use an IndexedStack for this. it will never unload the children. However , it will load them at all once [producing a little lag]

    body:IndexedStack(
              index: _selectedIndex ,
              children: <Widget>[
               FirstPage(),
               Webview(),
               //etc...
              ]
            ),

这篇关于如何在Flutter中使用BottomNavigationBar维护Webview状态的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！