有没有办法在 Flutter WebView 中导入外部脚本

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【中文标题】有没有办法在 Flutter WebView 中导入外部脚本【英文标题】：Is there a way to import external scripts in Flutter WebView 【发布时间】：2020-07-08 06:19:03 【问题描述】：

我正在尝试将外部脚本加载到 Flutter WebView 中，但它似乎不起作用。特别是关于 tinyMCE。所以目的是在一个AlertDialog中打开一个富文本编辑器，里面有WebView。这可能吗？

以下是我的html：

<html>
<head>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/tinymce/5.2.1/tinymce.min.js"></script>
</head>
<body>
<textarea id="test"></textarea>
<script>
  tinymce.init(
    selector: 'textarea#test',
    height: 500,
    menubar: false,
    plugins: [
      'advlist autolink lists link image charmap print preview anchor',
      'searchreplace visualblocks code fullscreen',
      'insertdatetime media table paste code help wordcount'
    ],
    toolbar: 'undo redo | formatselect | ' +
    'bold italic backcolor | alignleft aligncenter ' +
    'alignright alignjustify | bullist numlist outdent indent | ' +
    'removeformat | help',
  );
</script>
</body>
</html>

这就是我的小部件：

import 'dart:convert';

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

class RichTextEditor extends StatefulWidget 
  final String html;

  const RichTextEditor(
    this.html: '',
  );

  @override
  RichTextEditorState createState() => RichTextEditorState();


class RichTextEditorState extends State<RichTextEditor> 
  WebViewController _webViewController;

  @override
  Widget build(BuildContext context) 
    final String source = Uri.dataFromString(
      widget.html,
      mimeType: 'text/html',
      encoding: Encoding.getByName('utf-8'),
    ).toString();

    return Container(
      child: Material(
        child: Column(
          children: <Widget>[
            Row(
              children: <Widget>[
                IconButton(
                  icon: Icon(Icons.close),
                  onPressed: () => Navigator.of(context).pop(),
                ),
              ],
              mainAxisAlignment: MainAxisAlignment.end,
            ),
            Expanded(
              child: WebView(
                initialUrl: source,
                javascriptMode: JavascriptMode.unrestricted,
                onWebViewCreated: (WebViewController controller) 
                  _webViewController = controller;
                  _webViewController.loadUrl(source);
                ,
              ),
            ),
          ],
        ),
      ),
      padding: EdgeInsets.all(10.0),
    );
  

  @override
  void initState() 
    super.initState();

我在控制台中得到以下日志：

D/cr_Ime  (30910): [InputMethodManagerWrapper.java:30] Constructor
W/cr_AwContents(30910): onDetachedFromWindow called when already detached. Ignoring
D/cr_Ime  (30910): [InputMethodManagerWrapper.java:59] isActive: false
I/cr_Ime  (30910): ImeThread is not enabled.
D/EGL_emulation(30910): eglMakeCurrent: 0x8a0f4ca0: ver 2 0 (tinfo 0x8976d190)
W/cr_BindingManager(30910): Cannot call determinedVisibility() - never saw a connection for the pid: 30910
D/cr_Ime  (30910): [InputMethodManagerWrapper.java:59] isActive: true
D/cr_Ime  (30910): [InputMethodManagerWrapper.java:68] hideSoftInputFromWindow
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
D/EGL_emulation(30910): eglMakeCurrent: 0xb1e05240: ver 2 0 (tinfo 0xb1e03310)
W/cr_BindingManager(30910): Cannot call determinedVisibility() - never saw a connection for the pid: 30910
D/cr_Ime  (30910): [InputMethodManagerWrapper.java:59] isActive: true
D/cr_Ime  (30910): [InputMethodManagerWrapper.java:68] hideSoftInputFromWindow
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
I/art     (30910): Background sticky concurrent mark sweep GC freed 12(424B) AllocSpace objects, 0(0B) LOS objects, 0% free, 22MB/22MB, paused 10.801ms total 19.097ms
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
I/chromium(30910): [INFO:CONSOLE(9)] "Failed to initialize the editor as the document is not in standards mode. TinyMCE requires standards mode.", source: https://cdnjs.cloudflare.com/ajax/libs/tinymce/5.2.1/tinymce.min.js (9)
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread
W/art     (30910): Attempt to remove non-JNI local reference, dumping thread

任何帮助将不胜感激。谢谢！

【问题讨论】：

【参考方案1】：

要使 TinyMCE 正常工作，您还需要在 HTML 的开头添加 &lt;!DOCTYPE html&gt;（请参阅 https://community.tiny.cloud/communityQuestion?id=9064N000000MvpyQAC）。

你也可以试试我的插件flutter_inappwebview，如果它不适用于webview_flutter。 它是一个 Flutter 插件，可让您添加内联 WebView 或打开应用内浏览器窗口，并提供大量事件、方法和选项来控制 WebView。

这是一个使用initialData: InAppWebViewInitialData() 属性在 WebView 中注入初始 HTML 字符串的示例：

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

Future main() async 
  WidgetsFlutterBinding.ensureInitialized();
  runApp(new MyApp());


class MyApp extends StatefulWidget 
  @override
  _MyAppState createState() => new _MyAppState();


class _MyAppState extends State<MyApp> 
  InAppWebViewController webView;

  @override
  void initState() 
    super.initState();
  

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

  @override
  Widget build(BuildContext context) 
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('InAppWebView Example'),
        ),
        body: Container(
            child: Column(children: <Widget>[
              Expanded(
                  child: InAppWebView(
                    initialData: InAppWebViewInitialData(data: """
<!DOCTYPE html>
<html>
<head>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/tinymce/5.2.1/tinymce.min.js"></script>
</head>
<body>
<textarea id="test"></textarea>
<script>
  tinymce.init(
    selector: 'textarea#test',
    height: 500,
    menubar: false,
    plugins: [
      'advlist autolink lists link image charmap print preview anchor',
      'searchreplace visualblocks code fullscreen',
      'insertdatetime media table paste code help wordcount'
    ],
    toolbar: 'undo redo | formatselect | ' +
    'bold italic backcolor | alignleft aligncenter ' +
    'alignright alignjustify | bullist numlist outdent indent | ' +
    'removeformat | help',
  );
</script>
</body>
</html>
"""),
                    initialHeaders: ,
                    initialOptions: InAppWebViewGroupOptions(
                      crossPlatform: InAppWebViewOptions(
                        debuggingEnabled: true,
                      ),
                      android: AndroidInAppWebViewOptions(
                        builtInZoomControls: true
                      )
                    ),
                    onWebViewCreated: (InAppWebViewController controller) 
                      webView = controller;
                    ,
                    onLoadStart: (InAppWebViewController controller, String url) 

                    ,
                    onLoadStop: (InAppWebViewController controller, String url) 

                    
                  ))
            ])),
      ),
    );

截图：

【讨论】：

我正在尝试在 Flutter Web 中使用您的解决方案，但是使用上面的代码我得到以下错误：1）onLoadStart 和 onLoadStop 函数的第二个参数是 Uri 而不是 String 2）在浏览器中，我得到“flutter_inappwebview 插件尚不支持targetPlatform.windows” Ciao Francesco，如您所见，这个问题很老了，与此同时，插件也在进化。此示例适用于旧版本 4.0.0+4。对于第一个错误：您可以从参数中删除类型或将其更改为Uri（通常，URL 现在有Uri 输入新版本5！）。对于第二个错误：是的，该插件目前仅支持 Android 和 ios。我还会添加对 MacOS、Linux 和 Windows 的支持，但这需要很多时间

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