后退按钮在 flutter 中的 Webview 内不起作用

Question

I wrote the code by wrapping willpopScope so that I can get previous page of webview but it is not working thus it is closing the entire webView page.

Here is the full code:

class Resources extends StatefulWidget {
  @override
  _ResourcesState createState() => _ResourcesState();
}

class _ResourcesState extends State<Resources> {

  late WebViewController _controller;

  final Completer<WebViewController> _controllerCompleter =
  Completer<WebViewController>();

  Future<bool> pop(BuildContext context) async {
    if (await _controller.canGoBack()) {
      _controller.goBack();
      return Future.value(false);
    } else {
      return Future.value(true);
    }
  }
  @override
  void initState() {
    super.initState();
    if (Platform.isAndroid) WebView.platform = SurfaceAndroidWebView();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: SafeArea(
            child: WillPopScope(
              onWillPop:()=> pop(context),
              child: Scaffold(
                appBar: AppBar(),
                body: WebView(
                  gestureNavigationEnabled: true,
                  initialUrl: 'https://www.edhitch.com/login.html',
                  javascriptMode: JavascriptMode.unrestricted,
                  onWebViewCreated: (WebViewController webViewController) {
                    _controllerCompleter.future.then((value) => _controller = value);
                    _controllerCompleter.complete(webViewController);

                    },
                ),

              ),
          ),
            ),
        );
  }
}

I have used will scope which takes bool function pop kindly help me out with it.

Answer 1

Try to below code hope it helps to you:

Create Future function using async and it will return true

Future<bool> onWillPopFunction() async {
    return true;
}

and call your onWillPopFunction, function on onWillPop event

WillPopScope(
    child:  Scaffold(), 
    onWillPop: onWillPopFunction,
)

you also add alert box for warning like (exit your app or not?)

Or try below code

 IconButton(
      icon: Icon(Icons.arrow_back),
      onPressed: () => Navigator.pop(context, false),
    ),

Answer 2

You need to set the controller when the WebView is created and pop for the controller, not the app context:

onWillPop: (){
    _controller.goBack();
},

(updated, since "Controller.complete()" does not exist anymore)

onWebViewCreated: (WebViewController webViewController) {
    _controller = webViewController;
},