flutter - Flutter Webview 或 InAppWebview 不会每次都评估 javascript

Question

import 'dart:io';

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

Future main() async {
  WidgetsFlutterBinding.ensureInitialized();
  if (Platform.isAndroid) {
    await AndroidInAppWebViewController.setWebContentsDebuggingEnabled(true);

    var swAvailable = await AndroidWebViewFeature.isFeatureSupported(
        AndroidWebViewFeature.SERVICE_WORKER_BASIC_USAGE);
    var swInterceptAvailable = await AndroidWebViewFeature.isFeatureSupported(
        AndroidWebViewFeature.SERVICE_WORKER_SHOULD_INTERCEPT_REQUEST);

    if (swAvailable && swInterceptAvailable) {
      AndroidServiceWorkerController serviceWorkerController =
          AndroidServiceWorkerController.instance();

      serviceWorkerController.serviceWorkerClient = AndroidServiceWorkerClient(
        shouldInterceptRequest: (request) async {
          print(request);
          return null;
        },
      );
    }
  }
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  InAppWebViewController? webViewController;
  InAppWebViewGroupOptions options = InAppWebViewGroupOptions(
      crossPlatform: InAppWebViewOptions(
        useShouldOverrideUrlLoading: true,
        mediaPlaybackRequiresUserGesture: false,
        javaScriptCanOpenWindowsAutomatically: true,
        useShouldInterceptFetchRequest: true,
      ),
      android: AndroidInAppWebViewOptions(
        useShouldInterceptRequest: true,
        useHybridComposition: true,
      ),
      ios: IOSInAppWebViewOptions(
        allowsInlineMediaPlayback: true,
      ));

  String url = "";

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () {
        return Future.value(false);
      },
      child: MaterialApp(
        home: Scaffold(
          appBar: AppBar(
            centerTitle: true,
            title: const Text('InAppWebView Example'),
            leading: IconButton(
              icon: Icon(Icons.arrow_back),
              onPressed: () {
                Navigator.pop(context);
              },
            ),
          ),
          body: Container(
            child: Column(children: <Widget>[
              Container(
                padding: EdgeInsets.all(20.0),
                child: Text(url),
              ),
              Expanded(
                child: Container(
                  decoration: BoxDecoration(
                      border: Border.all(color: Colors.blueAccent)),
                  child: InAppWebView(
                    initialUrlRequest:
                        URLRequest(url: Uri.parse("https://youtube.com")),
                    initialOptions: options,
                    onWebViewCreated: (InAppWebViewController controller) {
                      webViewController = controller;
                    },
                    onLoadStart: (controller, url) async {
                      
                      setState(() {
                        this.url = url.toString();
                        controller
                            .evaluateJavascript(source: """alert('Hello')""");
                      });
                    },
                    onLoadStop: (controller, url) async {
                      
                    },
                    androidOnPermissionRequest:
                        (controller, origin, resources) async {
                      return PermissionRequestResponse(
                          resources: resources,
                          action: PermissionRequestResponseAction.GRANT);
                    },
                    shouldOverrideUrlLoading:
                        (controller, navigationAction) async {
                      var uri = navigationAction.request.url!;

                      // if (![ "http", "https", "file", "chrome",
                      //   "data", "javascript", "about"].contains(uri.scheme)) {
                      //   if (await canLaunch) {
                      //     // Launch the App
                      //     await launch(
                      //       url,
                      //     );
                      //     // and cancel the request
                      //     return NavigationActionPolicy.CANCEL;
                      //   }
                      // }

                      // return NavigationActionPolicy.ALLOW;
                    },
                    onUpdateVisitedHistory: (controller, url, androidIsReload) {
                      setState(() {
                        this.url = url.toString();
                      });
                    },
                    onProgressChanged:
                        (InAppWebViewController controller, int progress) {},
                  ),
                ),
              ),
            ]),
          ),
        ),
      ),
    );
  }
}

嘿伙计们，我在颤振中使用 inAppWebview ，似乎一些像 youtube 这样的网站不允许在初始 url 或加载后评估 javascript。虽然这在某些网站上按预期工作，但我尝试过 stackoverflow、flutter.dev 但在 youtube 上没有。

有人可以解释为什么吗？

谢谢

我正在使用 InAppWebview 5。