Flutter：组件10、倒计时

import 'dart:async';
import 'package:flutter/material.dart';class CountdownTimer extends StatefulWidget {final int seconds;final double? fontSize;final Color? textColor;final bool showDays;final bool showHours;final bool showMinutes;final bool showSeconds;final String separator;const CountdownTimer({super.key,required this.seconds,this.fontSize,this.textColor,this.showDays = true,this.showHours = true,this.showMinutes = true,this.showSeconds = true,this.separator = " : ",});@overrideState<CountdownTimer> createState() => _CountdownTimerState();
}class _CountdownTimerState extends State<CountdownTimer> {late Timer _timer;late int _remainingSeconds;bool _mounted = true;@overridevoid initState() {super.initState();_remainingSeconds = widget.seconds;_startTimer();}@overridevoid dispose() {_mounted = false;_timer.cancel();super.dispose();}void _startTimer() {_timer = Timer.periodic(const Duration(seconds: 1), (timer) {if (!_mounted) return;setState(() {if (_remainingSeconds > 0) {_remainingSeconds--;} else {_timer.cancel();}});});}String _formatNumber(int number) {return number.toString().padLeft(2, '0');}@overrideWidget build(BuildContext context) {final days = _remainingSeconds ~/ (24 * 3600);final hours = (_remainingSeconds % (24 * 3600)) ~/ 3600;final minutes = (_remainingSeconds % 3600) ~/ 60;final seconds = _remainingSeconds % 60;List<String> timeParts = [];if (widget.showDays && days > 0) {timeParts.add(_formatNumber(days));}if (widget.showHours) {timeParts.add(_formatNumber(hours));}if (widget.showMinutes) {timeParts.add(_formatNumber(minutes));}if (widget.showSeconds) {timeParts.add(_formatNumber(seconds));}return Text(timeParts.join(widget.separator),style: TextStyle(fontSize: widget.fontSize ?? 14,color: widget.textColor ?? Colors.black,),);}
} 

使用方式

// 基本使用
CountdownTimer(seconds: 3600, // 1小时
)// 自定义样式
CountdownTimer(seconds: 3600,fontSize: 20,textColor: Colors.red,
)// 只显示分秒
CountdownTimer(seconds: 3600,showDays: false,showHours: false,
)// 自定义分隔符
CountdownTimer(seconds: 3600,separator: " - ",
)