flutter - 如何在 flutter 中的每次重复动画之间添加延迟

Question

我的应用程序中有一个带有容器的 SlideTransition，它会永远重复，但我希望在每次重复后都有延迟。所以它会是这样的:

这是我的代码

  late final AnimationController _animationController = AnimationController(
    vsync: this,
    duration: const Duration(seconds: 1)
  )..repeat(reverse: true); // Here there should be the 500 millisecond delay

  late final Animation<Offset> _animation = Tween<Offset>(
    begin: Offset.zero,
    end: Offset(0, 1),
  ).animate(_animationController);

. . .

return Scaffold(
  body: Center(
    child: SlideTransition(
      position: _animation,
      child: Container(
        height: 100,
        width: 100,
        color: Colors.red,
      ),
    ),
  ),
);


   

Answer 1

只需更改您想要的持续时间 => await Future.delayed(Duration(seconds: 3)); 我用 seconds: 3 测试它以获得更好的想法。

 late final AnimationController _animationController =
      AnimationController(vsync: this, duration: const Duration(seconds: 3))
        ..forward(); 

 @override
  void initState() {
    super.initState();

    _animationController.addListener(() async {
      print(_animationController.status);

      if (_animationController.isCompleted) {
        await Future.delayed(Duration(seconds: 3));
        _animationController.reverse();
      } else if (_animationController.isDismissed) {
        await Future.delayed(Duration(seconds: 3));
        _animationController.forward();
      }
    });
  }