flutter - Flutter Dart Bottomsheet错误上下文=上下文

Question

我希望有人可以帮助我解决这个错误；
我已经使用了showModalBottomSheet窗口小部件，只是试图将结构实现到新站点上。我在BottomSheet中得到但只是不理解的错误与“context = context，”有关。我是否必须在其他地方实现void函数？还是应该创建一个扩展Header类的新类？有人能帮帮我吗？

class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      resizeToAvoidBottomPadding: false,
      body: ListView(
        children: <Widget>[
          Header(),
          //SelectOption(),
          //Chats(),
          //MoodsDetector(),
          //NextUp(),
          //PostFeed(),
        ],
      ),
    );
  }
}

class Header extends StatelessWidget {
  const Header({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: EdgeInsets.fromLTRB(25, 50, 50, 25),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: <Widget>[
          Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Text(
                'Welcome back,',
                style: TextStyle(color: secondColor, fontSize: 20),
              ),
              Text(
                'Henri',
                style: TextStyle(color: mainColor, fontSize: 30),
              ),
            ],
          ),
          Container(
            width: 50,
            height: 50,
            decoration: BoxDecoration(
              shape: BoxShape.circle,
              color: Colors.white,
              boxShadow: [
                BoxShadow(color: secondColor.withOpacity(0.5), blurRadius: 20),
              ],
            ),
            child: new IconButton(
              icon: new Icon(Icons.search),
              highlightColor: Colors.pink,
              onPressed: _showSearch,
            ),
          ),
        ],
      ),
    );
  }


  void _showSearch(){
    showModalBottomSheet(
        backgroundColor: Colors.white,
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.only(topRight: Radius.circular(30.0),topLeft: Radius.circular(30.0))
        ),
        isScrollControlled: true,
        isDismissible: true,
        context: context,
        builder: (builder) {
          return SingleChildScrollView(
            child: Column(
              children: <Widget>[
                Stack(
                  children: <Widget>[
                    SingleChildScrollView(
                      padding: const EdgeInsets.all(15.0),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: <Widget>[
                          Card(
                            elevation: 8.0,
                            shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(10.0)),
                            color: Colors.green,
                            child: ListTile(
                              onTap: () {
                                //open edit profile
                              },
                              title: Text(
                                "Rate your Friendship",
                                style: TextStyle(
                                  color: Colors.white,
                                  fontWeight: FontWeight.w500,
                                ),
                              ),
                              leading: CircleAvatar(
                                backgroundImage: AssetImage("assets/images/HenriKlein.jpeg"),
                              ),
                              trailing: Icon(
                                Icons.star,
                                color: Colors.white,
                              ),
                            ),
                          ),
                          const SizedBox(height:10.0),
                          Card(
                            elevation: 4.0,
                            margin: const EdgeInsets.fromLTRB(32.0, 8.0, 32.0, 16.0),
                            shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(10.0)),
                            child: Column(
                              children: <Widget>[
                                ListTile(
                                  leading: Icon(
                                    Icons.people_outline,
                                    color: Colors.lightGreen,
                                  ),
                                  title: Text("Invite to event"),
                                  trailing: Icon(Icons.keyboard_arrow_right),
                                  onTap: () {

                                  },
                                ),
                                sizedBox,
                                ListTile(
                                  leading: Icon(
                                    Icons.directions_run,
                                    color: Colors.lightGreen,
                                  ),
                                  title: Text("Challange Henri"),
                                  trailing: Icon(Icons.keyboard_arrow_right),
                                  onTap: () {},
                                ),
                                sizedBox,
                                ListTile(
                                  leading: Icon(
                                    Icons.phone_iphone,
                                    color: Colors.lightGreen,
                                  ),
                                  title: Text("Text/Call Henri"),
                                  trailing: Icon(Icons.keyboard_arrow_right),
                                  onTap: () { },
                                ),

                                sizedBox,
                                ListTile(
                                  leading: Icon(
                                    Icons.lock_outline,
                                    color: Colors.lightGreen,
                                  ),
                                  title: Text("Delete Friend"),
                                  trailing: Icon(Icons.keyboard_arrow_right),
                                  onTap: () {},
                                ),

                              ],
                            ),
                          ),
                          const SizedBox(height: 5.0),

                          Center(
                            child: Text(
                              "Friens since 09/20/2019",
                              style: TextStyle(
                                fontSize: 15.0,

                              ),
                              textAlign: TextAlign.center,
                            ),
                          ),
                          SizedBox(height: 20.0),
                          Container(
                            height: 40.0,
                            child: GestureDetector(
                              onTap: () {
                              },
                              child: Material(
                                borderRadius: BorderRadius.circular(50.0),
                                shadowColor: Colors.black,
                                color: Colors.green,
                                elevation: 7.0,
                                child: Center(
                                  child: Text(
                                    '27 mutural friends',                                                                       //Login Button
                                    style: TextStyle(
                                        color: Colors.white,
                                        fontWeight: FontWeight.bold,
                                        fontFamily: 'Montserrat'),
                                  ),
                                ),
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),

              ],
            ),
          );
        });
  }
}

Answer 1

由于context中未定义_showSearch，因此出现错误。

您应该修改函数定义并将上下文作为参数添加，如下所示:

void _showSearch(BuildContext context) {
...

并且在调用时，必须从调用它的位置传递小部件的上下文，如下所示:

child: new IconButton(
  icon: new Icon(Icons.search),
  highlightColor: Colors.pink,
  onPressed: () {
    _showSearch(context); //here
  },
),