Flutter Drawer

Flutter 系列文章 总体目录

Drawer 是抽屉布局，一般情况下Scaffold一起使用。
Drawer的属性就记住一个child就好，直接看使用：

class MyDrawer extends StatefulWidget {
  @override
  _MainDrawer createState() => _MainDrawer();
}

class _MainDrawer extends State<MyDrawer> {
  List<GroupData> dataList = [
    //widgets
    new GroupData("单个子控件的容器", [
      new GroupItem("Container", ContainerDemo()),
      new GroupItem("Padding", PaddingDemo()),
      new GroupItem("Center", CenterDemo()),
      new GroupItem("Align", AlignDemo()),
      new GroupItem("FittedBox", FittedBoxDemo()),
      new GroupItem("AspectRatio", AspectRatioDemo()),
    ]),
    new GroupData("多个子控件的容器", [
      new GroupItem("Row/Column", RowDemo()),
      new GroupItem("GridView", GridViewDemo()),
      new GroupItem("ListView", ListViewDemo()),
      new GroupItem("Expanded", ExpandedDemo()),
      new GroupItem("ExpansionTile", ExpansionTileDemo()),
    ]),
    new GroupData("基础控件", [
      new GroupItem("Image", ImageDemo()),
      new GroupItem("Icon", IconDemo()),
      new GroupItem("Button", ButtonDemo()),
      new GroupItem("Button2", Button2Demo()),
      new GroupItem("Scaffold", ScaffoldDemo()),
      new GroupItem("AppBar", AppBarDemo()),
      new GroupItem("Placeholder", PlaceholderDemo()),
    ]),
    new GroupData("Material", [
      new GroupItem("BottomNavigationBar", BottomNavigationBarDemo()),
      new GroupItem("TabBar", TabBarDemo()),
      new GroupItem("MaterialApp", MaterialAppDemo()),
      new GroupItem("PopupMenuButton", PopupMenuButtonDemo()),
    ]),
  ];

  int _selectedItemIndex = 0;
  Widget _selectedItemWidget = PopupMenuButtonDemo();
  String _title = "Text1";

  _onSelectedItem(BuildContext context, int index, GroupItem item) {
    if (index == _selectedItemIndex) {
      return;
    }
    Navigator.pop(context);
    setState(() {
      _selectedItemIndex = index;
      _selectedItemWidget = item.widget;
      _title = item.name;
    });
  }

  List<Widget> _createDrawerItems(BuildContext context, List<GroupData> list) {
    var drawerItems = <Widget>[];
    drawerItems.add(DrawHeader());
    for (var i = 0; i < list.length; i++) {
      var itemList = <Widget>[];
      for (var j = 0; j < list[i].group.length; j++) {
        itemList.add(new ListTile(
          title: Text(list[i].group[j].name),
          selected: _selectedItemIndex == i + j,
          onTap: () {
            _onSelectedItem(context, i + j, list[i].group[j]);
          },
        ));
      }
      if (list[i].groupName != null) {
        drawerItems.add(new ExpansionTile(
          title: Text(list[i].groupName),
          children: itemList,
        ));
      }
    }
    return drawerItems;
  }

  @override
  Widget build(BuildContext context) {
    var groupList = _createDrawerItems(context, dataList);
    return Scaffold(
      appBar: AppBar(title: Text(_title)),
      body: _selectedItemWidget,
      drawer: Drawer(
          child: ListView(
        children: groupList,
      )),
    );
  }
}

class GroupData {
  String groupName;
  List<GroupItem> group;

  GroupData(String groupName, List<GroupItem> group) {
    this.group = group;
    this.groupName = groupName;
  }
}

class GroupItem {
  String name;
  Widget widget;

  GroupItem(String name, Widget widget) {
    this.name = name;
    this.widget = widget;
  }
}