问题
Hi I developed a Flutter Plugin flutter_tex. It's based on the WebView. How do I add Flutter Web support for this??
I tried this example to show my HTML content.
import 'dart:ui' as ui;
void forWeb() {
if(kIsWeb){
// ignore: undefined_prefixed_name
ui.platformViewRegistry.registerViewFactory(
'hello-world-html',
(int viewId) => uni_html.IFrameElement()
..width = '640'
..height = '360'
..src = 'https://www.youtube.com/embed/IyFZznAk69U'
..style.border = 'none');
Directionality(
textDirection: TextDirection.ltr,
child: Center(
child: SizedBox(
width: 200,
height: 200,
child: HtmlElementView(viewType: 'hello-world-html'),
),
),
);
}
}
But this code is fine when building for the web but when for compiling on android I get this error even if I am not calling above code.
Compiler message:
../lib/flutter_tex.dart:139:10: Error: Getter not found: 'platformViewRegistry'.
ui.platformViewRegistry.registerViewFactory(
^^^^^^^^^^^^^^^^^^^^
Target kernel_snapshot failed: Exception: Errors during snapshot creation: null
build failed.
FAILURE: Build failed with an exception.
回答1:
You can copy paste run 3 files below main.dart
, mobileui.dart
and webui.dart
You can put mobile
and web
code in different files and use conditional import
This allow you to have different implement on mobile and web
import 'mobileui.dart' if (dart.library.html) 'webui.dart' as multiPlatform;
...
home: multiPlatform.TestPlugin(),
working demo
when run with Chrome
or Android Emulator
in Android Studio
main.dart
import 'package:flutter/material.dart';
import 'mobileui.dart' if (dart.library.html) 'webui.dart' as multiPlatform;
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: multiPlatform.TestPlugin(),
);
}
}
mobileui.dart
import 'package:flutter/material.dart';
class TestPlugin extends StatefulWidget {
@override
_TestPluginState createState() => _TestPluginState();
}
class _TestPluginState extends State<TestPlugin> {
@override
Widget build(BuildContext context) {
return Text("Mobile");
}
}
webui.dart
import 'package:flutter/material.dart';
import 'dart:html' as html;
import 'dart:js' as js;
import 'dart:ui' as ui;
class TestPlugin extends StatefulWidget {
TestPlugin();
_TestPluginState createState() => _TestPluginState();
}
class _TestPluginState extends State<TestPlugin> {
String createdViewId = 'map_element';
@override
void initState() {
// ignore: undefined_prefixed_name
ui.platformViewRegistry.registerViewFactory(
createdViewId,
(int viewId) => html.IFrameElement()
..width = MediaQuery.of(context).size.width.toString() //'800'
..height = MediaQuery.of(context).size.height.toString() //'400'
..srcdoc = """<!DOCTYPE html><html>
<head><title>Page Title</title></head><body><h1>This is a Heading</h1><p>This is a paragraph.</p></body></html>"""
..style.border = 'none');
super.initState();
}
@override
void dispose() {
super.dispose();
}
@override
Widget build(BuildContext context) {
return Container(
padding: EdgeInsets.symmetric(horizontal: 10),
decoration: BoxDecoration(
color: Colors.white,
border: Border.all(color: Colors.grey[300], width: 1),
borderRadius: BorderRadius.all(Radius.circular(5))),
width: 200,
height: 200,
child: Directionality(
textDirection: TextDirection.ltr,
child: HtmlElementView(
viewType: createdViewId,
)));
}
}
来源:https://stackoverflow.com/questions/60075516/webview-support-for-flutterweb-for-plugin-development