必须提供一个函数体。尝试添加函数体

我自己写的，因为statefulwidget没有自动创建模式，并且在 7 个不同的错误中我无法修复这个问题

import 'package:flutter/material.dart';

class NaberMain extends StatefulWidget {
  NaberMain({Key key}) : super(key: key)

  // ignore: empty_constructor_bodies
  @override 
  _NaberMainState createState() => _NaberMainState();
}

class _NaberMainState extends State<NaberMain> {
  @override
  Widget build(BuildContext context) {
    return Container(
    );
  }
}

之后缺少分号super(key: key)。添加分号。

class NaberMain extends StatefulWidget {
  NaberMain({Key key}) : super(key: key); //This is the semi-colon.

  @override 
  _NaberMainState createState() => _NaberMainState();
}

class _NaberMainState extends State<NaberMain> {
  @override
  Widget build(BuildContext context) {
    return Container(
    );
  }
}