在Flutter中推迟AnimationController动画的开始

Question

我试图将动画从一开始延迟 5 秒，这是我的代码片段，但它不能正常工作，因为从启动屏幕开始延迟 5 秒会更好.我试图制作一个单独的函数来负责延迟，但它也导致我在模拟器上显示错误。我尝试使用三元运算符并延迟它，但它也无法正常工作。我也希望我的动画在 7 秒内完成，我认为它也可以用三元运算符完成。我还不知道如何停止动画，所以我在动画中使用了很长的延迟使其不可见。

class BubbleBackground extends StatefulWidget {
  final Widget child;
  final double size;

  const BubbleBackground({
    Key key,
    @required this.child,
    @required this.size,
  }) : super(key: key);
  @override
  State<BubbleBackground> createState() => _BubbleBackgroundState();
}

class _BubbleBackgroundState extends State<BubbleBackground>
    with SingleTickerProviderStateMixin {
  bool timer = false;
  final longAnimationDuration = 100000;
  final shortAnimationDuration = 700;
  AnimationController _controller;
  @override
  void initState() {
    setState(() {
      // Future.delayed(Duration(seconds: 5), () {
      //   timer = true;
      // });
      timer = true;
    });

    _controller = AnimationController(
      lowerBound: 0.9,
      duration: Duration(
        milliseconds: timer
            ? Future.delayed(
                Duration(seconds: 5),
                () {
                  shortAnimationDuration;
                },
              )
            : longAnimationDuration,
      ),
      vsync: this,
    )..repeat(reverse: true);
    super.initState();
  }

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

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller,
      builder: (_, __) {
        return Transform.scale(
          scale: _controller.value,
          child: Container(
            width: widget.size,
            height: widget.size,
            alignment: Alignment.center,
            decoration: BoxDecoration(
              color: Colors.white,
              shape: BoxShape.circle,
            ),
            child: widget.child,
          ),
        );
      },
    );
  }
}

Answer 1

我发现我可以正常编写initState，并且我会得到理想的时间延迟结果

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

    _controller = AnimationController(
      lowerBound: 0.9,
      duration: Duration(milliseconds: shortAnimationDuration),
      vsync: this,
    );
    Future.delayed(Duration(seconds: 5), () {
      _controller.repeat(reverse: true);
    });
  }

在Flutter中推迟AnimationController动画的开始

Postpone the start of the AnimationController animation in Flutter

flutter

dart

animation

mobile

timer