如何使半透明的appbar颤动

import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';

class ShakingAppBar extends HookWidget {
  @override
  Widget build(BuildContext context) {
    final animationController = useAnimationController(
      duration: Duration(seconds: 1),
    );
    final curvedAnimation = CurvedAnimation(
      parent: animationController,
      curve: Curves.easeInOut,
    );

    animationController.repeat(reverse: true);

    return AnimatedBuilder(
      animation: curvedAnimation,
      builder: (context, child) {
        return Transform(
          transform: Matrix4.rotationZ(curvedAnimation.value * 0.05),
          child: AppBar(
            title: Text('Shaking AppBar'),
            backgroundColor: Colors.transparent,
            elevation: 0.0,
          ),
        );
      },
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      appBar: ShakingAppBar(),
      body: Center(
        child: Text('Hello World'),
      ),
    ),
  ));
}