These two intrinsics report different types of time. system_clock reports “wall time” or elapsed time. cpu_time reports time used by the CPU. On a multi-tasking machine these could be very different, e.g., if your process shared the CPU equally with three other processes and therefore received 25% of the CPU and used 10 cpu seconds, … Read more
Try to make the following changes to your code: First, you have to change the way you declare timerTest var timerTest : Timer? then in startTimer before instantiating check if timerTest is nil func startTimer () { guard timerTest == nil else { return } timerTest = Timer.scheduledTimer( timeInterval: TimeInterval(0.3), target : self, selector : … Read more
Here is an example using Timer.periodic : Countdown starts from 10 to 0 on button click : import ‘dart:async’; […] Timer _timer; int _start = 10; void startTimer() { const oneSec = const Duration(seconds: 1); _timer = new Timer.periodic( oneSec, (Timer timer) { if (_start == 0) { setState(() { timer.cancel(); }); } else { … Read more