Вы можете сделать это, добавив этот плагин и использовать его так:
Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: CircularCountDownTimer(
// Countdown duration in Seconds
duration: 10,
// Width of the Countdown Widget
width: MediaQuery.of(context).size.width / 2,
// Height of the Countdown Widget
height: MediaQuery.of(context).size.height / 2,
// Default Color for Countdown Timer
color: Colors.white,
// Filling Color for Countdown Timer
fillColor: Colors.red,
// Border Thickness of the Countdown Circle
strokeWidth: 5.0,
// Text Style for Countdown Text
textStyle: TextStyle(
fontSize: 22.0,
color: Colors.black87,
fontWeight: FontWeight.bold),
// true for reverse countdown (max to 0), false for forward countdown (0 to max)
isReverse: false,
// Function which will execute when the Countdown Ends
onComplete: () {
// Here, do whatever you want
print('Countdown Ended');
},
))