flutter - flutter keep alive widget 如何再次请求数据？

Question

我在用flutter写一个app，在A页面设置wantKeepAlive为true，然后在initState生命周期请求数据。现在，我跳转到B页面做了一些事情，然后又回到了A页面，我想再次请求数据，因为我在B页面做了一些事情，但是A页面一直保持事件状态，它从未运行过initState。那么，我应该如何重新请求数据呢？

Answer 1

我相信这就是您要找的:

class PageA extends StatefulWidget {
  @override
  _PageAState createState() => _PageAState();
}

class _PageAState extends State<PageA> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Page A'),
      ),
      body: Column(
        children: <Widget>[
          Text('Page A'),
          RaisedButton(
            onPressed: goToPageB,
            child: Text('Go to Page B'),
          )
        ],
      )
    );
  }

  void goToPageB(){
    Navigator.of(context).push(MaterialPageRoute(
      builder: (context) {
        return PageB();
      }
    )).then((result){
//      Once you come back from Page B you can
//      fetch your data for page A again here
    });
  }
}

class PageB extends StatefulWidget {
  @override
  _PageBState createState() => _PageBState();
}

class _PageBState extends State<PageB> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Page B'),
        ),
        body: Column(
          children: <Widget>[
            Text('Page B'),
            RaisedButton(
              onPressed: () => Navigator.of(context).pop(),
              child: Text('Go to Page A'),
            )
          ],
        )
    );
  }
}