用MouseRegion Package GestureDetector以获取鼠标事件。

return MouseRegion(
      onEnter: (event) {
        setState(() {
          following = true;
        });
      },
      onExit: (event) {
        setState(() {
          following = false;
        });
      },
      child: GestureDetector(

我为你做了一个示例代码。你可以很容易地跟踪鼠标，使你想要的AnimatedContainer或AnimatedSwitcher。
下面是结果

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const Center(
          child: MyStatefulWidget(),
        ),
      ),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({super.key});

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  bool isMouseEnter = true;
  String buttonText = "Follow";

  void _onExitMouse(PointerEvent details) {
    setState(() {
      isMouseEnter = false;
      buttonText = "Following";
    });
  }

  void _onEnterMouse(PointerEvent details) {
    setState(() {
      isMouseEnter = true;
      buttonText = "UnFollow";
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: MouseRegion(
          onEnter: _onEnterMouse,
          onExit: _onExitMouse,
          child: AnimatedContainer(
            width: 200,
            height: 50,
            decoration: BoxDecoration(
                borderRadius: BorderRadius.all(Radius.circular(isMouseEnter ? 30 : 10)),
                border: Border.all(
                    color: isMouseEnter ? Colors.red : Colors.lightBlueAccent,
                    width: 2)),
            duration: const Duration(milliseconds: 300),
            child: AnimatedSwitcher(
                duration: const Duration(milliseconds: 300),
                child: Text(
                  buttonText,
                  key: ValueKey(isMouseEnter),
                  style: Theme.of(context).textTheme.headline5?.copyWith(
                      color: isMouseEnter ? Colors.red : Colors.lightBlueAccent),
                )),
          ),
        ),
      ),
    );
  }
}