dart - 在 Flutter 中按后退键关闭抽屉

Question

我正在为现有项目添加 flutter。在 flutter 模块中，我有主页，它包含抽屉。但是在后面按 drawer 没有关闭。

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: HomePage(),
    drawer: Drawer(),
  );
}

Answer 1

给 Scaffold 一个 GlobalKey 并将你的小部件包装在 WillPopScope

GlobalKey<ScaffoldState> _globalKey = GlobalKey();
...

@override
Widget build(BuildContext context) {
  return Scaffold(
    key: _globalKey,
    drawer: Drawer(),
    body: WillPopScope(
      child: HomePage(),
      onWillPop: () {
        if (_globalKey.currentState.isDrawerOpen) {
          Navigator.pop(context); // closes the drawer if opened
          return Future.value(false); // won't exit the app
        } else {
          return Future.value(true); // exits the app
        }
      },
    ),
  );
}