desnot work on my ios device

[DavidMGT]

System info

Issue occurs on: iOS Plugin version: flutter_webview_plugin: any Flutter doctor output:

flutter: 0.1
flutter: ┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
flutter: │ #0   showLog (package:union_flutter/appkit/util/util.dart:1:1207)
flutter: │ #1   _WebViewPageState.initState.() (package:union_flutter/module/web_page/web_view_page.dart:33:7)
flutter: ├┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄
flutter: │ 🐛 onUrlChangeed https://pages.yiwuhaoyun.com/rent
flutter: └───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
flutter: ┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
flutter: │ #0   showLog (package:union_flutter/appkit/util/util.dart:1:1207)
flutter: │ #1   _WebViewPageState.initState.() (package:union_flutter/module/web_page/web_view_page.dart:33:7)
flutter: ├┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄
flutter: │ 🐛 onUrlChangeed http://pages.yiwuhaoyun.com/rent/

## Steps to Reproduce
here is my code 

import 'dart:core';

import 'package:flutter/material.dart';
import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';
import 'package:union_flutter/appkit/util/util.dart';

class WebViewPage extends StatefulWidget {
  final String url;
  final String title;
  static const String routeName = "/webview";

  WebViewPage({this.url, this.title});

  _WebViewPageState createState() => _WebViewPageState();
}

class _WebViewPageState extends State<WebViewPage> {
  final flutterWebviewPlugin = new FlutterWebviewPlugin();

  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
  var lineProgress;

  @override
  void initState() {
    super.initState();
    //showLog('WebViewPage ${Uri.encodeFull(widget.url)}');
    flutterWebviewPlugin.onUrlChanged.listen((String url) {
      showLog('onUrlChangeed '+url);
    });
    flutterWebviewPlugin.onProgressChanged.listen((progress) {
      print(progress);
      setState(() {
        lineProgress = progress;
      });
    });
  }

  _progressBar(double progress, BuildContext context) {
    return LinearProgressIndicator(
      backgroundColor: Colors.white70.withOpacity(0),
      value: progress == 1.0 ? 0 : progress,
      valueColor: new AlwaysStoppedAnimation<Color>(Colors.white),
    );
  }

  @override
  Widget build(BuildContext context) {
    return WebviewScaffold(
      appBar: AppBar(
        title: Text(widget.title),
        bottom: PreferredSize(
          child: _progressBar(lineProgress, context),
          preferredSize: Size.fromHeight(3.0),
        ),
      ),
      key: ObjectKey(widget.url),
      url: Uri.encodeFull(widget.url),
      withZoom: true,
      withLocalStorage: true,
      withJavascript: true,
      useWideViewPort: true,
      displayZoomControls: true,
      withOverviewMode: true,
    );
  }

  @override
  void dispose() {
    super.dispose();
  }
}

1.the onUrlChange was called twice.and change my url from “https” to "http"
2.I add it in my homepage   _pages.add(WebViewPage(
        url: URLS.RENT_URL,
        title: '租买货车',
      ));
3. ...

## Logs

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[shinriyo]

@DavidMGT

 static const String routeName = "/webview";

to

 static const String routeName = "/";