抽屉未定义答案

【问题标题】：Drawer is not define抽屉未定义
【发布时间】：2019-12-13 03:00:43
【问题描述】：

我收到一个错误说抽屉未定义，当我向正文添加一个 gridview.count 时，它现在给出此错误哪个抽屉未定义...如何解决此错误？

这是我的脚手架：

return new Scaffold(
  appBar: new AppBar(
    title: Stack(
      children: <Widget>[Text('PickerUp')],
    ),
    centerTitle: true,
  ),
  body: new GridView.count(
    crossAxisCount: 2,
    children: List.generate(100, (index) {
      return Center(
          child: Text('Item $index',
              style: Theme.of(context).textTheme.headline));
    }),

    // Drawer controls left menu drawer
    drawer: Container(
      width: 245,
      child: new Drawer(
        child: ListView(
          padding: EdgeInsets.zero,
          children: <Widget>[
            UserAccountsDrawerHeader(
              accountName: Text('Admin'),
              accountEmail: Text('test@admin.com'),
              currentAccountPicture: CircleAvatar(
                  backgroundImage: NetworkImage(
                      'https://images-wixmp-ed30a86b8c4ca887773594c2.wixmp.com/f/a89c3e38-b6f3-48a0-9f9e-df9a0129fb93/daghh5x-4a77b3ec-fd4f-4d17-9f84-5963a8cb5c03.png?token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJ1cm46YXBwOjdlMGQxODg5ODIyNjQzNzNhNWYwZDQxNWVhMGQyNmUwIiwiaXNzIjoidXJuOmFwcDo3ZTBkMTg4OTgyMjY0MzczYTVmMGQ0MTVlYTBkMjZlMCIsIm9iaiI6W1t7InBhdGgiOiJcL2ZcL2E4OWMzZTM4LWI2ZjMtNDhhMC05ZjllLWRmOWEwMTI5ZmI5M1wvZGFnaGg1eC00YTc3YjNlYy1mZDRmLTRkMTctOWY4NC01OTYzYThjYjVjMDMucG5nIn1dXSwiYXVkIjpbInVybjpzZXJ2aWNlOmZpbGUuZG93bmxvYWQiXX0.dWTFMrwnbAbj5TtUp9U_vQsohW7MnkRPymzR5wZQoV8')),
            ),
            ListTile(
              leading: Icon(Icons.search),
              title: Text('Search'),
            ),
            ListTile(
              leading: Icon(Icons.settings),
              title: Text('Settings'),
            ),
            ListTile(
              leading: Icon(Icons.arrow_back),
              title: Text('Logout'),
            ),
          ],
        ),
      ),
    ),
  ),
);

【问题讨论】：

标签： flutter visual-studio-code flutter-layout

【解决方案1】：

您必须确定括号。这是你的脚手架

return new Scaffold(
  appBar: new AppBar(
    title: Stack(
      children: <Widget>[Text('PickerUp')],
    ),
    centerTitle: true,
  ),
  // Drawer controls left menu drawer
  drawer: Container(
      width: 245,
      child: new Drawer(
        child: ListView(
          padding: EdgeInsets.zero,
          children: <Widget>[
            UserAccountsDrawerHeader(
              accountName: Text('Admin'),
              accountEmail: Text('test@admin.com'),
              currentAccountPicture: CircleAvatar(
                  backgroundImage: NetworkImage(
                      'https://images-wixmp-ed30a86b8c4ca887773594c2.wixmp.com/f/a89c3e38-b6f3-48a0-9f9e-df9a0129fb93/daghh5x-4a77b3ec-fd4f-4d17-9f84-5963a8cb5c03.png?token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJ1cm46YXBwOjdlMGQxODg5ODIyNjQzNzNhNWYwZDQxNWVhMGQyNmUwIiwiaXNzIjoidXJuOmFwcDo3ZTBkMTg4OTgyMjY0MzczYTVmMGQ0MTVlYTBkMjZlMCIsIm9iaiI6W1t7InBhdGgiOiJcL2ZcL2E4OWMzZTM4LWI2ZjMtNDhhMC05ZjllLWRmOWEwMTI5ZmI5M1wvZGFnaGg1eC00YTc3YjNlYy1mZDRmLTRkMTctOWY4NC01OTYzYThjYjVjMDMucG5nIn1dXSwiYXVkIjpbInVybjpzZXJ2aWNlOmZpbGUuZG93bmxvYWQiXX0.dWTFMrwnbAbj5TtUp9U_vQsohW7MnkRPymzR5wZQoV8')),
            ),
            ListTile(
              leading: Icon(Icons.search),
              title: Text('Search'),
            ),
            ListTile(
              leading: Icon(Icons.settings),
              title: Text('Settings'),
            ),
            ListTile(
              leading: Icon(Icons.arrow_back),
              title: Text('Logout'),
            ),
          ],
        ),
      )),
  body: new GridView.count(
    crossAxisCount: 2,
    children: List.generate(100, (index) {
      return Center(
          child: Text('Item $index',
              style: Theme.of(context).textTheme.headline));
    }),
  ),
);

【讨论】：

【解决方案2】：

括号放错了。

  body: new GridView.count(
    crossAxisCount: 2,
    children: List.generate(100, (index) {
      return Center(
          child: Text('Item $index',
              style: Theme.of(context).textTheme.headline));
    })), <- missed bracket

【讨论】：