推迟Flutter中AnimationController动画的开始

Question

我试图从一开始就将动画延迟5秒，这是我的代码片段，但它不能正常工作，因为最好从启动屏幕开始延迟5秒。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，但它也不能正常工作。我还希望我的动画在7秒内完成，我认为它也可以在三元运算符中完成。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

我发现我可以正常地写initState，并且我会得到时间延迟的理想结果

@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);
});
}