WebView 内部没有高度，滚动不起作用

问题描述 投票：0回答：4

在 Flutter 上...我尝试在所有支持滚动的可用容器中添加 Webview，但它在 Android 上不起作用。

ListView(
          shrinkWrap: true,
          children: <Widget>[
            Text("hiiiiiiiiiiiii "),
            Text("hiiiiiiiiiiiii "),
            Text("hiiiiiiiiiiiii "),
           Expanded(
                child: WebView(
                    key: Key("webview1"),
                    debuggingEnabled:  true,
                    javascriptMode: JavascriptMode.unrestricted,
                    initialUrl: "https://flutter.dev/")),
            Text("hiiiiiiiiiiiii "),
            Text("hiiiiiiiiiiiii "),
            Text("hiiiiiiiiiiiii "),
          ],
)
flutter webview
4个回答
11
投票

如果你想将可滚动的 WebView 放在其他小部件之间，并且 WebView 是可滚动的，其他小部件则不是，那么只需将 ListView 更改为 Column 即可：

Column(
  children: <Widget>[
    Text("hiiiiiiiiiiiii "),
    Text("hiiiiiiiiiiiii "),
    Container(
      height: 300,
      child: WebView(
          key: Key("webview1"),
          debuggingEnabled: true,
          javascriptMode: JavascriptMode.unrestricted,
          initialUrl: "https://flutter.dev/")
    ),
    Text("hiiiiiiiiiiiii "),
    Text("hiiiiiiiiiiiii "),
)

但是如果你想在 WebView 上有一些可滚动的小部件，那么尝试 CustomScrollView 或 SliverList。

你能说出你想要表达的确切逻辑吗？

补充：

如果你想要有可滚动区域和内部一些WebView，你必须知道WebView的高度：

ListView(
  physics: ClampingScrollPhysics(),
  children: <Widget>[
    Text("hiiiiiiiiiiiii "),
    Text("hiiiiiiiiiiiii "),
    ConstrainedBox(
      constraints: BoxConstraints(maxHeight: 10000),
        child: WebView(
          gestureRecognizers: Set()
            ..add(
              Factory<VerticalDragGestureRecognizer>(
                  () => VerticalDragGestureRecognizer(),
              ), // or null
            ),
            key: Key("webview1"),
            debuggingEnabled: true,
            javascriptMode: JavascriptMode.unrestricted,
            initialUrl: "https://flutter.dev/")),
    Text("hiiiiiiiiiiiii "),
    Text("hiiiiiiiiiiiii "),
  ],
);

动态获取WebView的高度，灵感在这里： https://gist.github.com/PonnamKarthik/877a90917a576ecff613d5169680d02c

3
投票

我一开始也有同样的问题。您可以指定传递哪些手势 使用 gestureRecognizers 参数连接到 webView 小部件。下面的代码有助于捕获垂直滚动事件。

       WebView(
       initialUrl: someUrl,
       gestureRecognizers: Set()
        ..add(Factory<VerticalDragGestureRecognizer>(
         () => VerticalDragGestureRecognizer())),
       )

我发现这篇文章对于 webview 也非常有用 Flutter 中 WebView 的强大功能

3
投票

感谢 dubace 的解决方案 gist.github.com/PonnamKarthik/877a90917a576ecff613d5169680d02c

问题解决了，现在我们可以在父可滚动容器中添加 Webview。

import 'dart:convert';

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Code Sample',
      builder: (BuildContext context, Widget navigator) {
        return MyStatelessWidget();
      },
    );
  }
}

class MyStatelessWidget extends StatefulWidget {
  MyStatelessWidget({Key key}) : super(key: key);

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

class _MyStatelessWidgetState extends State<MyStatelessWidget> {
  List<WebViewController> _listController = List();

  List<double> _heights =
      List<double>.generate(htmlStrings.length, (int index) => 20.0);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ListView.builder(
        shrinkWrap: true,
        itemCount: htmlStrings.length,
        itemBuilder: (context, index) {
          return Container(
            height: _heights[index] ?? 100.0,
            child: WebView(
              initialUrl:
                  'data:text/html;base64,${base64Encode(const Utf8Encoder().convert(htmlStrings[index]))}',
              onPageFinished: (some) async {
                double height = double.parse(await _listController[index]
                    .evaluateJavascript(
                        "document.documentElement.scrollHeight;"));
                setState(() {
                  _heights[index] = height;
                });
              },
              javascriptMode: JavascriptMode.unrestricted,
              onWebViewCreated: (controller) async {
                _listController.add(controller);
              },
            ),
          );
        },
      ),
    );
  }
}

final List<String> htmlStrings = [
  '''<p>Table shows some compounds and the name of their manufacturing process</p>
<table style="border-collapse: collapse; width: 100%; height: 85px;" border="1">
<tbody>
<tr style="height: 17px;">
<td style="width: 50%; text-align: center; height: 17px;">Compounds/Elements</td>
<td style="width: 50%; text-align: center; height: 17px;">Manufacture process</td>
</tr>
<tr style="height: 17px;">
<td style="width: 50%; height: 17px;">Nitric acid</td>
<td style="width: 50%; height: 17px;">Ostwald's process</td>
</tr>
<tr style="height: 17px;">
<td style="width: 50%; height: 17px;">Ammonia</td>
<td style="width: 50%; height: 17px;">Haber's process</td>
</tr>
<tr style="height: 17px;">
<td style="width: 50%; height: 17px;">Sulphuric acid</td>
<td style="width: 50%; height: 17px;">Contact process</td>
</tr>
<tr style="height: 17px;">
<td style="width: 50%; height: 17px;">Sodium</td>
<td style="width: 50%; height: 17px;">Down's process</td>
</tr>
</tbody>
</table>''',
  '''<p>\(L=[M{L }^{2 }{T }^{-2 }{A }^{-2 }]\)</p>
<p>\(C=[{M }^{-1 }{L }^{-2 }{T }^{4 }{A }^{2 }]\)</p>
<p>\(R=[M{L }^{2 }{T }^{-3 }{A }^{-2 }]\)</p>
<p>\(\therefore \frac {R}{L}=\frac{[M{L }^{2 }{T }^{-2 }{A }^{-2 }]}{[M{L }^{2 }{T }^{-3 }{A }^{-2 }]}=[T]\)</p>''',
  '''<p>Displacement(s)\(=\left(13.8\pm0.2\right)m\)</p>
<p>Time(t)\(=\left(4.0\pm0.3\right)s\)</p>
<p>Velocity(v)\(=\frac{13.8}{4.0}=3.45m{s}^{-1}\)</p>
<p>\(\frac{\delta v}{v}=\pm\left(\frac{\delta s}{s}+\frac{\delta t}{t}\right)=\pm\left(\frac{0.2}{13.8}+\frac{0.3}{4.0}\right)=\pm0.0895\)</p>
<p>\(\delta v =\pm0.0895*3.45=\pm0.3\)(rounding off to one place of decimal)</p>
<p>\(v=\left(3.45\pm0.3\right)m{s}^{-1}\)</p>''',
  '''<p>The only real numbers satisfying \(x^2=4\) are 2 and -2. But none of them satisfy the final condition, \(x+2=3\). So, there is no real number such that these conditions are met. Hence this is null set.</p>
<p>Note that, for \(x\) to be a memner of \(\{x:p(x),q(x)\}\),&nbsp;<em><strong>both</strong></em> \(p(x)\) and \(q(x)\) should be true.</p>''',
];
2
投票

第一种方法：-

制作一个完全可滚动的Widget，包含WebView（具有动态高度）以及其上方和下方的其他容器。所有内容都应该在父窗口小部件内滚动

确保 flutter 包：

webview_flutter: any
已正确安装。

1.创建

Future
fxn

    String hight;
    double webHight =400; //default some value
    Future funcThatMakesAsyncCall() async{
      var result =
             await controller.evaluateJavascript('document.body.scrollHeight'); 
    //here we call javascript for get browser data
             setState(() {
                       hight = result;
                          },);}

2.我们使用

SingleChildScrollView
滚动方向：Axis.vertical，

3.内部使用

Column

4.最后我们使用

Conatiner

里面

Container
我们使用
WebView

这里

Container
代码

               Container(
                height: webHight+20,
                child: WebView(
                initialUrl: widget.url,
                onPageFinished: (webhight)async{
                   await funcThatMakesAsyncCall();
                   setState((){
                      webHight= double.parse(hight);                          
                   });                        
                  },
                  javascriptMode: JavascriptMode.unrestricted,
                  onWebViewCreated: (WebViewController webViewController) {
                  
                  controller = webViewController;

                  },
                ),
              ),

第二种方法：-

插件版本：> 

webview_flutter: ^3.0.4

Column(
          children: [            
            Container(
              height: Get.height * 0.1,
              color: Colors.amber,
            ),
            Expanded(
              // height: 200,
              child: WebView(                              
                gestureNavigationEnabled: true,
                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
                  Factory<OneSequenceGestureRecognizer>(
                    () => EagerGestureRecognizer(),
                  ),
                },
                onWebViewCreated: (WebViewController webViewController) {
                  bscontroller.webcontroller = webViewController;
                },
                initialUrl: 'https://flutter.dev',
              ),
            )
          ],
        ),

当我再次陷入同一问题并尝试我的旧答案时，但这一次对我来说不起作用，所以我想出了另一种方法

以及同一问题的第二个答案

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