Question

我正在尝试在Flutter应用中实现webView。它与CircularProgressIndicator配合良好，但我无法隐藏加载栏。这是我的webview dart文件：

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

class MyWebView extends StatelessWidget {
  final String title;
  final String selectedUrl;

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

  MyWebView({
    @required this.title,
    @required this.selectedUrl,
  });

 bool isLoading = true;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(title),
        ),
        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(),
          ],
        ),
    );
  }

它仅显示错误：未为类“ MyWebView”定义方法“ setState”。有人可以建议我如何解决这个问题吗？

Answer 1

@Enayet，您正在setState中使用StatelessWidget。您只能在StatefulWidget中进行操作。如果要使用setState，则需要将窗口小部件类更改为以下类别，

class MyWebView extends StatefulWidget {
  final String title;
  final String selectedUrl;

  const MyWebView({Key key, @required this.title, @required this.selectedUrl}) : super(key: key);

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

class MyWebViewState extends State<MyWebView> {
....

在此处了解有关StatefulWidget的更多信息-https://api.flutter.dev/flutter/widgets/StatefulWidget-class.html

如何更改Flutter WebView setState（）方法

1 个答案: