我可以访问子部件中的scafold吗？

Question

如果我想在我的自定义小部件内使用小吃店，我能做到吗？CustomWidget是否可以进入脚手架？既然小吃店应该在脚手架里？

return Scaffold(
  backgroundColor: HexColor("f4f4f4"),
  body: SafeArea(
      child: Column(
    children: [
      CustomAppBar(
        width: width,
        topBarHeight: topBarHeight,
        height: height,
      ),
      CustomWidget(),
      ]))

Answer 1

是的，您可以在小部件中使用它，如下所示：

CustomWidget(BuildContext ctx) {
   if(condition) // it can also be a button action or something like that
     ScaffoldMessenger.of(ctx)
       .showSnackBar(
           SnackBar(content: Text(''))); //Replace Text('') with your widget
}

并将context传递给您的CustomWidget(context)。

Answer 2

您可以将ScaffoldState键传递给构造函数。

例如：

创建全局ScaffoldState密钥

final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();

以下是完整的代码：

class Test extends StatefulWidget {
  const Test({Key? key}) : super(key: key);

  @override
  TestState createState() => TestState();
}

class _TestState extends State<Test> {
  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: _scaffoldKey,
      body: GetData(
        scaffoldKey: _scaffoldKey,
      ),
    );
  }
}

子部件：

class GetData extends StatefulWidget {
  const GetData({
    Key? key,
    required this.scaffoldKey,
  }) : super(key: key);

  final GlobalKey<ScaffoldState> scaffoldKey;
  @override
  GetDataState createState() => GetDataState();
}

class _GetDataState extends State<GetData> {
  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
        onPressed: () {
          widget.scaffoldKey.currentState
              ?.showSnackBar(const SnackBar(content: Text('content')));
        },
        child: Text('Show SnackBar'));
  }
}