在TextField中动态显示suffixIcon

import 'package:flutter/material.dart';

class DynamicSuffixIconTextField extends StatefulWidget {
  @override
  _DynamicSuffixIconTextFieldState createState() =>
      _DynamicSuffixIconTextFieldState();
}

class _DynamicSuffixIconTextFieldState
    extends State<DynamicSuffixIconTextField> {
  bool isSuffixIconVisible = false;

  @override
  Widget build(BuildContext context) {
    return TextField(
      onChanged: (text) {
        setState(() {
          isSuffixIconVisible = text.length > 0;
        });
      },
      decoration: InputDecoration(
        suffixIcon: isSuffixIconVisible
            ? IconButton(
                icon: Icon(Icons.clear),
                onPressed: () {
                  setState(() {
                    isSuffixIconVisible = false;
                  });
                },
              )
            : null,
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      appBar: AppBar(
        title: Text('Dynamic Suffix Icon TextField'),
      ),
      body: Center(
        child: DynamicSuffixIconTextField(),
      ),
    ),
  ));
}