在Flutter中创建自定义时钟小部件

import 'package:flutter/material.dart';
import 'dart:async';

class ClockWidget extends StatefulWidget {
  @override
  _ClockWidgetState createState() => _ClockWidgetState();
}

class _ClockWidgetState extends State<ClockWidget> {
  Timer _timer;
  DateTime _currentTime;

  @override
  void initState() {
    super.initState();
    _currentTime = DateTime.now();
    _timer = Timer.periodic(Duration(seconds: 1), (timer) {
      setState(() {
        _currentTime = DateTime.now();
      });
    });
  }

  @override
  void dispose() {
    _timer.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Text(
        _formatTime(_currentTime),
        style: TextStyle(fontSize: 24),
      ),
    );
  }

  String _formatTime(DateTime time) {
    String hour = time.hour.toString().padLeft(2, '0');
    String minute = time.minute.toString().padLeft(2, '0');
    String second = time.second.toString().padLeft(2, '0');
    return '$hour:$minute:$second';
  }
}

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Clock App',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('Clock App'),
        ),
        body: Center(
          child: ClockWidget(),
        ),
      ),
    );
  }
}