Question

我有这个螺丝（波纹管），我正在试着在上面打开一个抽屉。每当我单击按钮时，我都会得到以下回报：

class _BarberListState extends State<BarberList> {
  final TextStyle dropdownMenuItem =
  TextStyle(color: Colors.black, fontSize: 18);
  final GlobalKey<ScaffoldState> _key = GlobalKey<ScaffoldState>();
  final primary = Color(0xFF63736B);
  final secondary = Color(0xFF0C0E0B);
  final green = Color(0xFF79FF00);
  final Color active = Colors.grey.shade800;
  final Color divider = Colors.grey.shade600;

  final String image = 'https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png';


  final List<Map> barberLists = [
    {
      "name": "Barbearia do Laender",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png",
      "description":
      "Barbaria conceituada que está no mercado de trabalho a mais de 10 anos e com vários clientes satisfeitos",
      "details":
      "Detalhes como produtos a serem vendidas e serviços adicionais: \n* Corte de Barba: R\$15,00 \n*Pomoda modeladora: R\$50,00",
      "detailImage":
      "https://cdn.pixabay.com/photo/2019/09/17/18/52/barbershop-4484297__340.jpg",
      "prices": "R\$15,00-R\$40,00"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
    {
      "name": "Barbearia do PA",
      "location": "Rua Paraná, 184 - Cidade de Deus",
      "type": "De 09h ás 18h - Seg. à Sex.",
      "phone": "(37) 99122-3338",
      "logoText":
      "https://cdn.pixabay.com/photo/2017/01/13/01/22/rocket-1976107_960_720.png"
    },
  ];


  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      key: _key,
      home: Scaffold(
        drawer: Drawer(
          child: Container(
            padding: const EdgeInsets.only(left: 16.0, right: 40),
            decoration: BoxDecoration(
                color: primary, boxShadow: [BoxShadow(color: Colors.black45)]),
            width: 300,
            child: SafeArea(
              child: SingleChildScrollView(
                child: Column(
                  children: <Widget>[
                    Container(
                      alignment: Alignment.centerRight,
                      child: IconButton(
                        icon: Icon(
                          Icons.power_settings_new,
                          color: active,
                        ),
                        onPressed: () {},
                      ),
                    ),
                    Container(
                      height: 90,
                      alignment: Alignment.center,
                      decoration: BoxDecoration(
                          shape: BoxShape.circle,
                          gradient: LinearGradient(
                              colors: [Colors.orange, Colors.deepOrange])),
                      child: CircleAvatar(
                        radius: 40,
                        backgroundImage: CachedNetworkImageProvider(image),
                      ),
                    ),
                    SizedBox(height: 5.0),
                    Text(
                      "erika costell",
                      style: TextStyle(
                          color: Colors.black,
                          fontSize: 18.0,
                          fontWeight: FontWeight.w600),
                    ),
                    Text(
                      "@erika07",
                      style: TextStyle(color: active, fontSize: 16.0),
                    ),
                    SizedBox(height: 30.0),
                    _buildRow(Icons.home, "Home"),
                    _buildDivider(),
                    _buildRow(Icons.person_pin, "My profile"),
                    _buildDivider(),
                    _buildRow(Icons.message, "Messages", showBadge: true),
                    _buildDivider(),
                    _buildRow(Icons.notifications, "Notifications",
                        showBadge: true),
                    _buildDivider(),
                    _buildRow(Icons.settings, "Settings"),
                    _buildDivider(),
                    _buildRow(Icons.email, "Contact us"),
                    _buildDivider(),
                    _buildRow(Icons.info_outline, "Help"),
                    _buildDivider(),
                  ],
                ),
              ),
            ),
          ),
        ),
        resizeToAvoidBottomInset: false,
        backgroundColor: Color(0xfff0f0f0),
        body: SingleChildScrollView(
          child: Container(
            height: MediaQuery.of(context).size.height,
            width: MediaQuery.of(context).size.width,
            child: Stack(
              children: <Widget>[
                Container(
                  padding: EdgeInsets.only(top: 145),
                  height: MediaQuery.of(context).size.height,
                  width: double.infinity,
                  child: ListView.builder(
                      itemCount: barberLists.length,
                      itemBuilder: (BuildContext context, int index) {
                        return buildList(context, index);
                      }),
                ),
                Container(
                  height: 140,
                  width: double.infinity,
                  decoration: BoxDecoration(
                      color: green,
                      borderRadius: BorderRadius.only(
                          bottomLeft: Radius.circular(30),
                          bottomRight: Radius.circular(30))),
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 30),
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: <Widget>[
                        MaterialButton(
                          padding: const EdgeInsets.all(8.0),
                          shape: RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(10.0)),
                          child: Icon(Icons.menu),
                          color: Colors.white,
                          textColor: Colors.black,
                          minWidth: 0,
                          height: 40,
                          onPressed: () {
                              _key.currentState.openDrawer();
                          },

                        ),
                        Text(
                          "Barbearias",
                          style: TextStyle(color: Colors.white, fontSize: 24),
                        ),
                        IconButton(
                          onPressed: () {},
                          icon: Icon(
                            Icons.filter_list,
                            color: Colors.white,
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
                Container(
                  child: Column(
                    children: <Widget>[
                      SizedBox(
                        height: 110,
                      ),
                      Padding(
                        padding: EdgeInsets.symmetric(horizontal: 20),
                        child: Material(
                          elevation: 5.0,
                          borderRadius: BorderRadius.all(Radius.circular(30)),
                          child: TextField(
                            // controller: TextEditingController(text: locations[0]),
                            cursorColor: Theme.of(context).primaryColor,
                            style: dropdownMenuItem,
                            decoration: InputDecoration(
                                hintText: "Procurar Barbearias",
                                hintStyle: TextStyle(
                                    color: Colors.black38, fontSize: 16),
                                prefixIcon: Material(
                                  elevation: 0.0,
                                  borderRadius:
                                  BorderRadius.all(Radius.circular(30)),
                                  child: Icon(Icons.search),
                                ),
                                border: InputBorder.none,
                                contentPadding: EdgeInsets.symmetric(
                                    horizontal: 25, vertical: 13)),
                          ),
                        ),
                      ),
                    ],
                  ),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }

我尝试遵循一些示例来解决该问题，但是我失败了。我真的很乐于助人。如果需要的话，我会将其他方法发布在抽屉上，但是我认为此屏幕上有内容，但是我不知道我在做什么错。

Answer 1

不要忘记将全局密钥分配给支架中的密钥专有性

Scaffold(
  key: _scaffoldKey,...

Answer 2

该消息不存在，因为密钥在MaterialApp中。当我在脚手架上声明钥匙时，抽屉将根据需要工作。

“方法'openDrawer'在null上被调用。”我需要有关Flutter的帮助

2 个答案: