轻击扑动时导航扩展

Question

我正在构建一个颤动的应用程序，我正在使用ExpansionTile的示例代码：

import 'package:flutter/material.dart';

class ExpansionTileSample extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: const Text('ExpansionTile'),
        ),
        body: new ListView.builder(
          itemBuilder: (BuildContext context, int index) =>
              new EntryItem(data[index]),
          itemCount: data.length,
        ),
      ),
    );
  }
}

// One entry in the multilevel list displayed by this app.
class Entry {
  Entry(this.title, [this.children = const <Entry>[]]);

  final String title;
  final List<Entry> children;
}

// The entire multilevel list displayed by this app.
final List<Entry> data = <Entry>[
  new Entry(
    'Chapter A',
    <Entry>[
      new Entry(
        'Section A0',
        <Entry>[
          new Entry('Item A0.1'),
          new Entry('Item A0.2'),
          new Entry('Item A0.3'),
        ],
      ),
      new Entry('Section A1'),
      new Entry('Section A2'),
    ],
  ),
  new Entry(
    'Chapter B',
    <Entry>[
      new Entry('Section B0'),
      new Entry('Section B1'),
    ],
  ),
  new Entry(
    'Chapter C',
    <Entry>[
      new Entry('Section C0'),
      new Entry('Section C1'),
      new Entry(
        'Section C2',
        <Entry>[
          new Entry('Item C2.0'),
          new Entry('Item C2.1'),
          new Entry('Item C2.2'),
          new Entry('Item C2.3'),
        ],
      ),
    ],
  ),
];

// Displays one Entry. If the entry has children then it's displayed
// with an ExpansionTile.
class EntryItem extends StatelessWidget {
  const EntryItem(this.entry);

  final Entry entry;

  Widget _buildTiles(Entry root) {
    if (root.children.isEmpty) return new ListTile(
       onTap: () { print("I can be tapped but I dont't figure out how to navigate"); },
       title: new Text(root.title));
    return new ExpansionTile(
      key: new PageStorageKey<Entry>(root),
      title: new Text(root.title),
      children: root.children.map(_buildTiles).toList(),
    );
  }

  @override
  Widget build(BuildContext context) {
    return _buildTiles(entry);
  }
}

https://flutter.io/catalog/samples/expansion-tile-sample/

我想点击较低的项目（项目A0.1，项目A0.2，项目A0.3，项目C2.0等）以浏览其他页面（每次一个不同）。我添加了onTap，但我只能在控制台中打印一些内容。如何实现这一目标？

Answer 1

您可以通过将MaterialPageRoute推送到导航器来导航到屏幕 print('Navigate to SomePageClass'); Navigator.push(context, MaterialPageRoute(builder: (_) => SomePageClass()));

Answer 2

您可以在创建上下文时将上下文从ListView.builder传递到EntryItem方法，并在OnClick中使用它导航到OtherPage。

import 'package:flutter/material.dart';

void main() => runApp(new ExpansionTileSample());

class ExpansionTileSample extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: const Text('ExpansionTile'),
        ),
        body: new ListView.builder(
          itemBuilder: (BuildContext context, int index) =>
          new EntryItem(data[index], context),
          itemCount: data.length,
        ),
      ),
    );
  }
}

// One entry in the multilevel list displayed by this app.
class Entry {
  Entry(this.title, [this.children = const <Entry>[]]);

  final String title;
  final List<Entry> children;
}

// The entire multilevel list displayed by this app.
final List<Entry> data = <Entry>[
  new Entry(
    'Chapter A',
    <Entry>[
      new Entry(
        'Section A0',
        <Entry>[
          new Entry('Item A0.1'),
          new Entry('Item A0.2'),
          new Entry('Item A0.3'),
        ],
      ),
      new Entry('Section A1'),
      new Entry('Section A2'),
    ],
  ),
  new Entry(
    'Chapter B',
    <Entry>[
      new Entry('Section B0'),
      new Entry('Section B1'),
    ],
  ),
  new Entry(
    'Chapter C',
    <Entry>[
      new Entry('Section C0'),
      new Entry('Section C1'),
      new Entry(
        'Section C2',
        <Entry>[
          new Entry('Item C2.0'),
          new Entry('Item C2.1'),
          new Entry('Item C2.2'),
          new Entry('Item C2.3'),
        ],
      ),
    ],
  ),
];

// Displays one Entry. If the entry has children then it's displayed
// with an ExpansionTile.
class EntryItem extends StatelessWidget {
  const EntryItem(this.entry, this.context);

  final Entry entry;
  final BuildContext context;

  Widget _buildTiles(Entry root) {
    if (root.children.isEmpty) return new ListTile(
        onTap: () { print("I can be tapped but I dont't figure out how to navigate");
        Navigator.of(context).push(new MaterialPageRoute(builder: (context) {
          return new OtherScreen();
        }));
        },
        title: new Text(root.title));
    return new ExpansionTile(
      key: new PageStorageKey<Entry>(root),
      title: new Text(root.title),
      children: root.children.map(_buildTiles).toList(),
    );
  }

  @override
  Widget build(BuildContext context) {
    return _buildTiles(entry);
  }
}