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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('TapGestureRecognizer  手势识别（拖曳）'),
        ),
        body: GestureRecognizerPage(),
      ),
    );
  }
}

class GestureRecognizerPage extends StatefulWidget {
  @override
  _GestureRecognizerPageState createState() => _GestureRecognizerPageState();
}

class _GestureRecognizerPageState extends State<GestureRecognizerPage> {
  TapGestureRecognizer recognizer = TapGestureRecognizer();

  bool toggle = true;
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Text('点击文字放大'),
          Text.rich(
            TextSpan(
                text: '你好',
                style: TextStyle(
                  fontSize: toggle ? 16 : 40,
                ),
                recognizer: recognizer
                  ..onTap = () {
                    setState(() {
                      toggle = !toggle;
                    });
                  }),
          ),
        ],
      ),
    );
  }
}