Flutter webView没有完成加载栏

Question

您好，我正在为我的应用中的 Flutter webView 实现而苦苦挣扎。它只是不会停止 circularProgressIndicator。

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';

class MyWebView extends StatelessWidget {
  final String selectedUrl;
  final Completer<WebViewController> _controller =  Completer<WebViewController>();
  MyWebView({
    @required this.selectedUrl,
  });
  bool isLoading = true;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[
          new WebView(
            initialUrl: selectedUrl,
            javascriptMode: JavascriptMode.unrestricted,
            onWebViewCreated: (WebViewController webViewController) {
              _controller.complete(webViewController);
            },
            onPageFinished: (finish) {
                isLoading = false;
            },
          ),
          isLoading ? Center(child: CircularProgressIndicator()) : Container(),
        ],
      ),
    );
  }
}

从我的代码中可以看出... isLoading 值未更改为 false 。因为它是一个无状态小部件，所以我不能在这里使用 setState()。我通过以下方式从另一个页面调用此 webView：

return Scaffold(body: new MyWebView( selectedUrl:"https://www.google.com"),);

selectedUrl 是我从不同页面传递的动态值

Answer 1

您可以在下面复制粘贴运行完整代码
你可以使用StatefulBuilder

代码sn-p

 return StatefulBuilder(
        builder: (BuildContext context, StateSetter setState) {
      return Scaffold(
        body: Stack(

...     

        onPageFinished: (finish) {
            setState(() {
              isLoading = false;
            });
          },

工作演示

编辑修订后的完整代码使用 IndexedStack

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:webview_flutter/webview_flutter.dart';

class MyWebView extends StatelessWidget {
  final String selectedUrl;
  final Completer<WebViewController> _controller =
      Completer<WebViewController>();
  MyWebView({
    @required this.selectedUrl,
  });
  //bool isLoading = true;
  num _stackToView = 1;

  @override
  Widget build(BuildContext context) {
    return StatefulBuilder(
        builder: (BuildContext context, StateSetter setState) {
      return Scaffold(
        body: IndexedStack(
          index: _stackToView,
          children: <Widget>[
            new WebView(
              initialUrl: selectedUrl,
              javascriptMode: JavascriptMode.unrestricted,
              onWebViewCreated: (WebViewController webViewController) {
                _controller.complete(webViewController);
              },
              onPageFinished: (finish) {
                print("onPageFinished");
                setState(() {
                  _stackToView = 0;
                });
              },
            ),
            Center(child: CircularProgressIndicator())
          ],
        ),
      );
    });
  }
}

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @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, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: new MyWebView(selectedUrl: "https://flutter.dev/"),
    );
  }
}

完整代码

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:webview_flutter/webview_flutter.dart';

class MyWebView extends StatelessWidget {
  final String selectedUrl;
  final Completer<WebViewController> _controller =
      Completer<WebViewController>();
  MyWebView({
    @required this.selectedUrl,
  });
  bool isLoading = true;
  @override
  Widget build(BuildContext context) {
    return StatefulBuilder(
        builder: (BuildContext context, StateSetter setState) {
      return Scaffold(
        body: Stack(
          children: <Widget>[
            new WebView(
              initialUrl: selectedUrl,
              javascriptMode: JavascriptMode.unrestricted,
              onWebViewCreated: (WebViewController webViewController) {
                _controller.complete(webViewController);
              },
              onPageFinished: (finish) {
                setState(() {
                  isLoading = false;
                });
              },
            ),
            isLoading
                ? Center(child: CircularProgressIndicator())
                : Container(),
          ],
        ),
      );
    });
  }
}

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @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, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: new MyWebView(selectedUrl: "https://flutter.dev/"),
    );
  }
}