Hibok/lib/utils/count_down_button.dart

import 'dart:async';

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

class CountDownButton extends StatefulWidget{

  final String text;
  final Function callBack;
  CountDownButton(this.text,this.callBack);

  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return CountDownButtonState();
  }

}
class CountDownButtonState extends State<CountDownButton> {

  int secondsPassed = 5*60;
//  int secondsPassed =10;
  Timer timer;
  void handleTick() {
//    if (isActive) {

  if(secondsPassed==1){
    widget.callBack();
    timer?.cancel();
    return;
  }

    setState(() {
      secondsPassed = secondsPassed - 1; //需要更新UI
    });
//    }
  }


  getFull(int sec){
    return sec<10?'0$sec':'$sec';
  }
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    timer = Timer.periodic(Duration(seconds: 1), (Timer t){
      handleTick();
    });
  }

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

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    //  ～/ 取整操作
    int seconds = secondsPassed % 60;
    int minutes = secondsPassed ~/ 60;
    return Container(
      alignment: Alignment.center,
      margin: EdgeInsets.only(left: 30, right: 30, top: 20,bottom: 20),
      height: 48,
      child: RaisedButton(
          color: Color(0xff3875E9),
          shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.all(Radius.circular(10))),
          child:   RichText(
              maxLines: 1,
              textAlign: TextAlign.center,
              text: TextSpan(children: [
                TextSpan(
                    text: widget.text,
                    style: TextStyle(
                        color: Colors.white,
                        fontSize: 18)),
                TextSpan(
                    text:' ('+ getFull(minutes)+' : '+getFull(seconds)+')',
                    style: TextStyle(
                        color: Colors.white, fontSize: 14)),
              ])) ,
          onPressed: () async{

          }),
    );
  }

}