where is expected to appear myWebView where is only show a string not webview

[cuihee]

where is expected to appear myWebView where is only show a string not webview.
and the string is myWebview's url

just like:
return WebviewScaffold(url: myUrl, .......);
the same as
return Text($myUrl);

My source code（if you need）(copy from this project's exmaple)
import 'dart:async';

import 'package:flutter/material.dart';

import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';

const kAndroidUserAgent =
'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Mobile Safari/537.36';

String selectedUrl = 'https://flutter.dev';

class MyFlutterWebViewApp extends StatelessWidget {
final flutterWebViewPlugin = FlutterWebviewPlugin();

@OverRide
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter WebView Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
routes: {
'/': () => const MyHomePage(title: 'Flutter WebView Demo'),
'/widget': () {
return WebviewScaffold(
url: selectedUrl,
appBar: AppBar(
title: const Text('Widget WebView'),
),
withZoom: true,
withLocalStorage: true,
hidden: true,
initialChild: Container(
color: Colors.redAccent,
child: const Center(
child: Text('Waiting.....'),
),
),
bottomNavigationBar: BottomAppBar(
child: Row(
children: [
IconButton(
icon: const Icon(Icons.arrow_back_ios),
onPressed: () {
flutterWebViewPlugin.goBack();
},
),
IconButton(
icon: const Icon(Icons.arrow_forward_ios),
onPressed: () {
flutterWebViewPlugin.goForward();
},
),
IconButton(
icon: const Icon(Icons.autorenew),
onPressed: () {
flutterWebViewPlugin.reload();
},
),
],
),
),
);
},
},
);
}
}

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

final String title;

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

class _MyHomePageState extends State {
// Instance of WebView plugin
final flutterWebViewPlugin = FlutterWebviewPlugin();

// On destroy stream
StreamSubscription _onDestroy;

// On urlChanged stream
StreamSubscription _onUrlChanged;

// On urlChanged stream
StreamSubscription _onStateChanged;

StreamSubscription _onHttpError;

StreamSubscription _onScrollYChanged;

StreamSubscription _onScrollXChanged;

final _urlCtrl = TextEditingController(text: selectedUrl);

final _codeCtrl = TextEditingController(text: 'window.navigator.userAgent');

final _scaffoldKey = GlobalKey();

final _history = [];

@OverRide
void initState() {
super.initState();

flutterWebViewPlugin.close();

_urlCtrl.addListener(() {
  selectedUrl = _urlCtrl.text;
});

// Add a listener to on destroy WebView, so you can make came actions.
_onDestroy = flutterWebViewPlugin.onDestroy.listen((_) {
  if (mounted) {
    // Actions like show a info toast.
    _scaffoldKey.currentState.showSnackBar(const SnackBar(content: const Text('Webview Destroyed')));
  }
});

// Add a listener to on url changed
_onUrlChanged = flutterWebViewPlugin.onUrlChanged.listen((String url) {
  if (mounted) {
    setState(() {
      _history.add('onUrlChanged: $url');
    });
  }
});

_onScrollYChanged = flutterWebViewPlugin.onScrollYChanged.listen((double y) {
  if (mounted) {
    setState(() {
      _history.add('Scroll in Y Direction: $y');
    });
  }
});

_onScrollXChanged = flutterWebViewPlugin.onScrollXChanged.listen((double x) {
  if (mounted) {
    setState(() {
      _history.add('Scroll in X Direction: $x');
    });
  }
});

_onStateChanged = flutterWebViewPlugin.onStateChanged.listen((WebViewStateChanged state) {
  if (mounted) {
    setState(() {
      _history.add('onStateChanged: ${state.type} ${state.url}');
    });
  }
});

_onHttpError = flutterWebViewPlugin.onHttpError.listen((WebViewHttpError error) {
  if (mounted) {
    setState(() {
      _history.add('onHttpError: ${error.code} ${error.url}');
    });
  }
});

}

@OverRide
void dispose() {
// Every listener should be canceled, the same should be done with this stream.
_onDestroy.cancel();
_onUrlChanged.cancel();
_onStateChanged.cancel();
_onHttpError.cancel();
_onScrollXChanged.cancel();
_onScrollYChanged.cancel();

flutterWebViewPlugin.dispose();

super.dispose();

}

@OverRide
Widget build(BuildContext context) {
return Scaffold(
key: _scaffoldKey,
appBar: AppBar(
title: const Text('Plugin example app'),
),
body: SingleChildScrollView(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Container(
padding: const EdgeInsets.all(24.0),
child: TextField(controller: _urlCtrl),
),
RaisedButton(
onPressed: () {
flutterWebViewPlugin.launch(
selectedUrl,
rect: Rect.fromLTWH(0.0, 0.0, MediaQuery.of(context).size.width, 300.0),
userAgent: kAndroidUserAgent,
);
},
child: const Text('Open Webview (rect)'),
),
RaisedButton(
onPressed: () {
flutterWebViewPlugin.launch(selectedUrl, hidden: true);
},
child: const Text('Open "hidden" Webview'),
),
RaisedButton(
onPressed: () {
flutterWebViewPlugin.launch(selectedUrl);
},
child: const Text('Open Fullscreen Webview'),
),
RaisedButton(
onPressed: () {
Navigator.of(context).pushNamed('/widget');
},
child: const Text('Open widget webview'),
),
Container(
padding: const EdgeInsets.all(24.0),
child: TextField(controller: _codeCtrl),
),
RaisedButton(
onPressed: () {
final future = flutterWebViewPlugin.evalJavascript(_codeCtrl.text);
future.then((String result) {
setState(() {
_history.add('eval: $result');
});
});
},
child: const Text('Eval some javascript'),
),
RaisedButton(
onPressed: () {
setState(() {
_history.clear();
});
flutterWebViewPlugin.close();
},
child: const Text('Close'),
),
RaisedButton(
onPressed: () {
flutterWebViewPlugin.getCookies().then((m) {
setState(() {
_history.add('cookies: $m');
});
});
},
child: const Text('Cookies'),
),
Text(_history.join('\n'))
],
),
),
);
}
}