Load html from assets folder and add query parameters with webview_flutter package - flutter

Question

I want to send query parameters to my HTML in the assets folder with the webview_flutter package.
I added the HTML file to my pubspec.yaml file.
This is my code.
//Dart
import 'dart:convert';
//flutter
import 'package:flutter/services.dart';
import 'package:flutter/material.dart';
//plugins
import 'package:webview_flutter/webview_flutter.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: HomePage(),
);
}
}
class HomePage extends StatefulWidget {
#override
HomePageState createState() {
return HomePageState();
}
}
class HomePageState extends State<HomePage> {
WebViewController _controller;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('Help')),
body: WebView(
initialUrl: 'about:blank',
onWebViewCreated: (WebViewController webViewController) {
_controller = webViewController;
_loadHtmlFromAssets();
},
),
);
}
_loadHtmlFromAssets() async {
String fileText = await rootBundle.loadString('assets/web/index.html');
_controller.loadUrl(Uri.dataFromString(fileText,
mimeType: 'text/html', encoding: Encoding.getByName('utf-8'))
.toString());
}
}
I tried to add parameters like this. but it can't load HTML.
_loadHtmlFromAssets() async {
String fileText = await rootBundle
.loadString('assets/web/index.html?url=https://flutter.github.io/assets-for-api-docs/assets/videos/bee.mp4');
_controller.loadUrl(Uri.dataFromString(fileText,
mimeType: 'text/html', encoding: Encoding.getByName('utf-8'))
.toString());
}
I also thoughts about the JavaScript the javascriptChannels it can send data from java script to the dart file. but I have no idea how to send data from dart file to html file with the web view?