颤振将时钟小部件添加到列

flutter adding a clock widget to column

我必须在 flutter 中使用时钟向导,如果直接插入 body 中,它工作正常,但我想在列中使用它,但它显示错误。我试图将它用作另一个有状态的小部件并调用列的内部子项,但仍然出现错误。任何帮助..???

import 'package:analog_clock_example/demo.dart';
import 'package:flutter/material.dart';

import 'package:analog_clock/analog_clock.dart';

void main() => runApp(MyApp());
//void main() => runDemo();

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) => MaterialApp(
          home: Scaffold(
        body: AnalogClock(),
      ));
}

我认为它会给您带来错误,因为您可能没有设置其约束。
尝试这样的事情,

import 'package:analog_clock_example/demo.dart';
import 'package:flutter/material.dart';

import 'package:analog_clock/analog_clock.dart';

void main() => runApp(MyApp()); 

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) => MaterialApp(
          home: Scaffold(
          body: Column(
               children: [
                  Container(
                    height: 300.0,       // Missing Constraints
                    width: 300.0,
                    child: AnalogClock(),
                 ),
             ],
          ),
      ),
    );
}

确保你停下来,然后 运行 再做一次,而不是 Hot Reload。希望有用!