如何截取基于AndroidViews实现的WebView (webview_flutter)截图？

import 'dart:typed_data';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';

GlobalKey webViewKey = GlobalKey();

RepaintBoundary(
  key: webViewKey,
  child: WebView(
    // WebView的相关配置
  ),
),

Future<Uint8List> captureWebView() async {
  RenderRepaintBoundary boundary = webViewKey.currentContext.findRenderObject();
  ui.Image image = await boundary.toImage(pixelRatio: 2.0);
  ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
  return byteData.buffer.asUint8List();
}

Uint8List screenshot = await captureWebView();