flutter 使用showDialog制作的简洁的登录界面

// 这个地方我们因该使用 stl 记得改回来
class HYHomeScreen extends StatefulWidget {
  @override
  _HYHomeScreenState createState() => _HYHomeScreenState();
}

class _HYHomeScreenState extends State {



  @override
  Widget build(BuildContext context) {
//    验证使用的Key
    final _formKey = GlobalKey();
    final nameController = TextEditingController();
    final passwordController = TextEditingController();

    return Scaffold(
      appBar: HYHomeAppBar(context),
      body: HYHomeContent(),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: () {
          showDialog(
            context: context,
            builder: (BuildContext context) {
              return AlertDialog(
                content: Stack(
                  overflow: Overflow.visible,
                  children: [
                    Positioned(
                      right: -40.px,
                      top: -40.px,
                      child: Container(
                        margin: EdgeInsets.only(left: 400.px),
                        child: InkResponse(
                          onTap: () {
                            Navigator.of(context).pop();
                          },
                          child: CircleAvatar(
                            child: Icon(Icons.close),
                            backgroundColor: Colors.red,
                          ),
                        ),
                      ),
                    ),
                    Container(
                      width: 200.px,
//                      color: Colors.red,
                      child: Form(
                        key: _formKey,
                        child: Column(
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Padding(
                              padding: EdgeInsets.all(8.px),
                              child: TextFormField(
                                decoration: InputDecoration(
                                  labelText: "username",
                                  icon: Padding(
                                    padding: EdgeInsets.only(top: 15.px),
                                    child: Icon(Icons.supervised_user_circle),
                                  )
                                ),
                                controller: nameController,
                                validator: (value) {
                                  if( value.isEmpty ) {
                                    return "请输入用户名";
                                  }
                                  return null;
                                },
                              ),
                            ),
                            Padding(
                              padding: EdgeInsets.all(8.px),
                              child: TextFormField(
                                decoration: InputDecoration(
                                  labelText: "password",
                                  icon: Padding(
                                    padding: EdgeInsets.only(top: 15.px),
                                    child: Icon(Icons.lock),
                                  )
                                ),
                                controller: passwordController,
                                validator: (value) {
                                  if( value.isEmpty ) {
                                    return "请输入密码";
                                  }
                                  return null;
                                },
                              ),
                            ),
                            Padding(
                              padding: EdgeInsets.only(top: 15.px),
                              child: RaisedButton(
                                child: Text("登录"),
                                onPressed: () {
                                  if (_formKey.currentState.validate()) {
                                    _formKey.currentState.save();
                                    print("name : ${nameController.text}");
                                    nameController.text = "";
                                    print("password: ${passwordController.text}");
                                    passwordController.text = "";
//                                    const timeout = const Duration(seconds: 1);
//                                    Timer.periodic(timeout, (timer){
////                                      print(timer);
//                                      Navigator.of(context).pop();
//                                    });
                                  }
                                },
                              ),
                            )
                          ],
                        ),
                      ),
                    )
                  ],
                )
              );
            }
          );
        },
      ),
    );
  }

  @override
  void dispose() {
    // TODO: implement dispose
    super.dispose();
  }
}