Flutter-如何获取屏幕小部件的图片？

import 'package:flutter/material.dart';

class MyWidget extends StatelessWidget {
  GlobalKey globalKey = GlobalKey();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My Widget'),
      ),
      body: RepaintBoundary(
        key: globalKey,
        child: Center(
          child: Text('Hello, World!'),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          _captureWidget();
        },
        child: Icon(Icons.camera),
      ),
    );
  }

  Future<void> _captureWidget() async {
    RenderRepaintBoundary boundary =
        globalKey.currentContext.findRenderObject();
    ui.Image image = await boundary.toImage();
    ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
    Uint8List pngBytes = byteData.buffer.asUint8List();

    // 处理图片数据，例如保存到本地或上传到服务器
    // ...
  }
}