将打开的SnackBar内部函数发送到AppBar

Question

我有一个带有表单的页面。用户单击“保存”后，它将显示一个SnackBar。保存按钮位于单独的自定义AppBar小部件中（位于单独的文件中），它具有2个函数，该函数从带有表单的页面发送。 AppBar出于可重用目的而分开。

我尝试使用Builder方法，但是它不起作用。然后我使用了Global Key方法，它不会给我一个错误，但是仍然没有SnackBar。

import 'package:flutter/material.dart';

import '../models/author.dart';
import '../widgets/edit_app_bar.dart';

class AuthorEditPage extends StatefulWidget {
  static const PAGE_TITLE = 'Edit Author';
  static const ROUTE_NAME = '/author-edit';

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

class _AuthorEditPageState extends State<AuthorEditPage> {
  @override
  Widget build(BuildContext context) {
    final _operation = ModalRoute.of(context).settings.arguments as String;
    final GlobalKey<ScaffoldState> _scaffoldKey =
        new GlobalKey<ScaffoldState>();

    Author _initialize() {
      return Author(
        id: null,
        name: 'Test',
        nameOther: null,
        facebook: null,
        website: null,
        lastUpdated: DateTime.now().toIso8601String(),
      );
    }

    void _displaySnackBar(Author author) {
      _scaffoldKey.currentState.showSnackBar(
        SnackBar(
          content: Text(
            'Author: ${author.name} added',
          ),
        ),
      );
    }

    return Scaffold(
      key: _scaffoldKey,
      appBar: EditAppBar(
        title: AuthorEditPage.PAGE_TITLE,
        saveAndAddNew: () async {
          Author author = _initialize();
          bool result = await author.createUpdateDelete(_operation);
          if (result) {
            _displaySnackBar(author);
            setState(() {});
          }
        },
        save: () async {
          Author author = _initialize();
          bool result = await author.createUpdateDelete(_operation);
          if (result) {
            _displaySnackBar(author);
            Navigator.of(context).pop();
          }
        },
      ),
      body: null,
    );
  }
}

自定义应用栏

import 'package:flutter/material.dart';

class EditAppBar extends StatelessWidget with PreferredSizeWidget {
  EditAppBar({
    Key key,
    @required this.title,
    @required this.saveAndAddNew,
    @required this.save,
  }) : super(key: key);

  final String title;
  final Function saveAndAddNew;
  final Function save;

  @override
  Widget build(BuildContext context) {
    return AppBar(
      title: Text(
        title,
      ),
      actions: <Widget>[
        IconButton(
          icon: Icon(
            Icons.add,
          ),
          onPressed: saveAndAddNew,
        ),
        IconButton(
          icon: Icon(
            Icons.save,
          ),
          onPressed: save,
        ),
      ],
    );
  }

  @override
  Size get preferredSize => Size.fromHeight(kToolbarHeight);
}

非常感谢任何帮助/指导！

Answer 1

不需要您使用必须具有脚手架的小吃店的另一种快速方法是使用名为Flushbar的软件包。这非常简单，并且消除了所有样板代码Flushbar Link