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文章目录
  1. 1. 常见问题
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int countValue = 10;
Timer _timer;

void startTimer() {
  final Duration duration = Duration(seconds: 1);
  cancelTimer();

  _timer = Timer.periodic(duration, (timer) {
    countValue = countValue - 1;
    if (this.mounted) {
      setState((){
        //..
      });
    }
    print(countValue);
    if (countValue <= 0) {
      cancelTimer();
    }
  });
}

常见问题

  1. Widget销毁时取消Timer

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    @override
    void dispose() {
      cancelTimer();
      super.dispose();
    }

  2. 生命周期变动

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    @override
    void didChangeAppLifecycleState(AppLifecycleState state) {
      switch(state) {
        case AppLifecycleState.resumed: {
          break;
        }
        case AppLifecycleState.paused: {
          cancelTimer();
          break;
        }
        case AppLifecycleState.inactive: {
          cancelTimer();
          break;
        }
        case AppLifecycleState.detached: {
          cancelTimer();
          break;
        }
      }
      super.didChangeAppLifecycleState(state);
    }
文章目录
  1. 1. 常见问题