如果触摸外部，则颤动移除OverlayEntry

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('OverlayEntry Example'),
        ),
        body: Center(
          child: GestureDetector(
            onTap: () {
              // 触摸到OverlayEntry之外的区域时，颤动并移除OverlayEntry
              removeOverlayEntry();
            },
            child: Text(
              'Tap here to remove OverlayEntry',
              style: TextStyle(fontSize: 20),
            ),
          ),
        ),
      ),
    );
  }
}

OverlayEntry overlayEntry;

void showOverlayEntry(BuildContext context) {
  overlayEntry = OverlayEntry(
    builder: (BuildContext context) {
      return Positioned(
        top: 100,
        left: 100,
        child: Container(
          width: 200,
          height: 200,
          color: Colors.red,
          child: Center(
            child: Text(
              'OverlayEntry',
              style: TextStyle(fontSize: 20, color: Colors.white),
            ),
          ),
        ),
      );
    },
  );
  Overlay.of(context).insert(overlayEntry);
}

void removeOverlayEntry() {
  if (overlayEntry != null) {
    overlayEntry.remove();
    overlayEntry = null;
  }
}