Basic

sample.packages.flutter.lib.src.widgets.basic.6311.

The following example shows a blue rectangular that turns yellow when hovered. Since the hover state is completely contained within a widget that unconditionally creates the MouseRegion, you can ignore the aforementioned restriction.

  
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: 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({Key? key}) : super(key: key);

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

class _MyStatefulWidgetState extends State {
  bool hovered = false;

  @override
  Widget build(BuildContext context) {
    return Container(
      height: 100,
      width: 100,
      decoration: BoxDecoration(color: hovered ? Colors.yellow : Colors.blue),
      child: MouseRegion(
        onEnter: (_) {
          setState(() {
            hovered = true;
          });
        },
        onExit: (_) {
          setState(() {
            hovered = false;
          });
        },
      ),
    );
  }
}