无需读取资产，然后从数据 uri 加载，只需传递资产路径，如下所示：
_loadHtmlFromAssets() async {
_webViewController.loadUrl('file:///android_asset/flutter_assets/files/index.html');
}
在index.html文件中，脚本路径应该是相对的。对我来说，index.html 和 index.js 位于同一路径中，所以这是有效的：
<script src="index.js"></script>
And my pubspec.yml看起来像这样：
assets:
- files/index.html
- files/index.js
Edit
平台独立的解决方案使用本地资产服务器 https://pub.dev/packages/local_assets_server:
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:local_assets_server/local_assets_server.dart';
import 'package:webview_flutter/webview_flutter.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) => MaterialApp(home: MyWidget());
}
class MyWidget extends StatefulWidget {
@override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
String address;
int port;
bool isListening = false;
@override
initState() {
_initServer();
super.initState();
}
_initServer() async {
final server = new LocalAssetsServer(
address: InternetAddress.loopbackIPv4,
assetsBasePath: 'files',
);
final address = await server.serve();
setState(() {
this.address = address.address;
port = server.boundPort;
isListening = true;
});
}
List<String> propList = [];
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('My WebView'),
),
body: !isListening ? Center(child: CircularProgressIndicator()) : WebView(
initialUrl: 'http://$address:$port',
javascriptMode: JavascriptMode.unrestricted,
onWebViewCreated: (WebViewController webViewController) {
}),
);
}
}
对于 Android，添加usesCleartextTraffic="true"在清单文件中：
<application
....
android:usesCleartextTraffic="true"
