WebView不能在flutter中加载两个不同的url？

Question

我在 build 方法的第一行打印 url 消息。而这里，url是对的，但是webView没有效果。 我用的是webview_flutter lib，版本是0.3.13；

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

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

class WebPage extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _WebPageState();
  }
}

class _WebPageState extends State<WebPage> {
  String url = "https://flutter.dev/";

  void _changeUrl() {
    setState(() {
      this.url = "https://github.com/flutter/flutter";
    });
  }

  @override
  Widget build(BuildContext context) {
    print("url:" + url);
    return MaterialApp(
        theme: ThemeData(primarySwatch: Colors.blue),
        home: Scaffold(
          appBar: AppBar(
            title: Text("WebPage"),
          ),
          body: WebView(
            initialUrl: url,
            javascriptMode: JavascriptMode.unrestricted,
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: _changeUrl,
            child: Icon(Icons.replay),
          ),
        ));
  }
}

我排除了 webView 加载第二个 url，但它没有。

Answer 1

你需要像这样使用 web-view 控制器类方法

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

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

class WebPage extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _WebPageState();
  }
}

class _WebPageState extends State<WebPage> {
  WebViewController controller;
  var url = "https://flutter.dev/";

  changeUrl() {
    setState(() {
    url = "https://github.com/flutter/flutter";
      controller.loadUrl(url);
    });
  }

  @override
  Widget build(BuildContext context) {
    print("url:" + url);
    return MaterialApp(
        theme: ThemeData(primarySwatch: Colors.blue),
        home: Scaffold(
          appBar: AppBar(
            title: Text("WebPage"),
          ),
    body: WebView(
          // key: _key,
          javascriptMode: JavascriptMode.unrestricted,
          initialUrl: url,
          onWebViewCreated: (WebViewController webViewController) {
            controller = webViewController;
          }),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          changeUrl();
        },
            child: Icon(Icons.replay),
          ),
        ));
  }
}

更多的控制器方法可以在这里找到flutter web-view class methods