webview_flutter仓库地址：webview_flutter | Flutter package

github地址：https://github.com/flutter/packages/tree/main/packages/webview_flutter/webview_flutter

要打开非https协议的网页，需要在安卓平台上添加权限：android:usesCleartextTraffic=”true”

打开网页demo：

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// ignore_for_file: public_member_api_docs
import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';
// #docregion platform_imports
// Import for Android features.
import 'package:webview_flutter_android/webview_flutter_android.dart';
// Import for iOS features.
import 'package:webview_flutter_wkwebview/webview_flutter_wkwebview.dart';
// #enddocregion platform_imports
void main() => runApp(const MaterialApp(home: WebViewExample()));
const String kNavigationExamplePage = '''


The navigation delegate is set to block navigation to the youtube website.


https://www.youtube.com/
https://www.google.com/

''';
const String kLocalExamplePage = '''

Local demo page

This is an example page used to demonstrate how to load a local file or HTML
string using the Flutter
webview plugin.

''';
const String kTransparentBackgroundPage = '''

body { background: transparent; margin: 0; padding: 0; }
#container { position: relative; margin: 0; padding: 0; width: 100vw; height: 100vh; }
#shape { background: red; width: 200px; height: 200px; margin: 0; padding: 0; position: absolute; top: calc(50% - 100px); left: calc(50% - 100px); }
p { text-align: center; }
Transparent background test
''';
const String kLogExamplePage = '''

Local demo page

This page is used to test the forwarding of console logs to Dart.

.btn-group button {
padding: 24px; 24px;
display: block;
width: 25%;
margin: 5px 0px 0px 0px;
}
Error
Warning
Info
Debug
Log
''';
class WebViewExample extends StatefulWidget {
const WebViewExample({super.key});
@override
State createState() => _WebViewExampleState();
}
class _WebViewExampleState extends State {
late final WebViewController _controller;
@override
void initState() {
super.initState();
// #docregion platform_features
late final PlatformWebViewControllerCreationParams params;
if (WebViewPlatform.instance is WebKitWebViewPlatform) {
params = WebKitWebViewControllerCreationParams(
allowsInlineMediaPlayback: true,
mediaTypesRequiringUserAction: const {},
);
} else {
params = const PlatformWebViewControllerCreationParams();
}
final WebViewController controller =
WebViewController.fromPlatformCreationParams(params);
// #enddocregion platform_features
controller
..setJavaScriptMode(JavaScriptMode.unrestricted)
..setBackgroundColor(const Color(0x00000000))
..setNavigationDelegate(
NavigationDelegate(
onProgress: (int progress) {
debugPrint('WebView is loading (progress : $progress%)');
},
onPageStarted: (String url) {
debugPrint('Page started loading: $url');
},
onPageFinished: (String url) {
debugPrint('Page finished loading: $url');
},
onWebResourceError: (WebResourceError error) {
debugPrint('''
Page resource error:
code: ${error.errorCode}
description: ${error.description}
errorType: ${error.errorType}
isForMainFrame: ${error.isForMainFrame}
''');
},
onNavigationRequest: (NavigationRequest request) {
if (request.url.startsWith('https://www.youtube.com/')) {
debugPrint('blocking navigation to ${request.url}');
return NavigationDecision.prevent;
}
debugPrint('allowing navigation to ${request.url}');
return NavigationDecision.navigate;
},
onUrlChange: (UrlChange change) {
debugPrint('url change to ${change.url}');
},
onHttpAuthRequest: (HttpAuthRequest request) {
openDialog(request);
},
),
)
..addJavaScriptChannel(
'Toaster',
onMessageReceived: (JavaScriptMessage message) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text(message.message)),
);
},
)
..loadRequest(Uri.parse('http://192.168.1.171:5173/#/pad?team=red'));
// #docregion platform_features
if (controller.platform is AndroidWebViewController) {
AndroidWebViewController.enableDebugging(true);
(controller.platform as AndroidWebViewController)
.setMediaPlaybackRequiresUserGesture(false);
}
// #enddocregion platform_features
_controller = controller;
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.green,
body: WebViewWidget(controller: _controller),
// floatingActionButton: favoriteButton(),
);
}
Widget favoriteButton() {
return FloatingActionButton(
onPressed: () async {
final String? url = await _controller.currentUrl();
if (mounted) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text('Favorited $url')),
);
}
},
child: const Icon(Icons.favorite),
);
}
Future openDialog(HttpAuthRequest httpRequest) async {
final TextEditingController usernameTextController =
TextEditingController();
final TextEditingController passwordTextController =
TextEditingController();
return showDialog(
context: context,
barrierDismissible: false,
builder: (BuildContext context) {
return AlertDialog(
title: Text('${httpRequest.host}: ${httpRequest.realm ?? '-'}'),
content: SingleChildScrollView(
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
TextField(
decoration: const InputDecoration(labelText: 'Username'),
autofocus: true,
controller: usernameTextController,
),
TextField(
decoration: const InputDecoration(labelText: 'Password'),
controller: passwordTextController,
),
],
),
),
actions: [
// Explicitly cancel the request on iOS as the OS does not emit new
// requests when a previous request is pending.
TextButton(
onPressed: () {
httpRequest.onCancel();
Navigator.of(context).pop();
},
child: const Text('Cancel'),
),
TextButton(
onPressed: () {
httpRequest.onProceed(
WebViewCredential(
user: usernameTextController.text,
password: passwordTextController.text,
),
);
Navigator.of(context).pop();
},
child: const Text('Authenticate'),
),
],
);
},
);
}
}
enum MenuOptions {
showUserAgent,
listCookies,
clearCookies,
addToCache,
listCache,
clearCache,
navigationDelegate,
doPostRequest,
loadLocalFile,
loadFlutterAsset,
loadHtmlString,
transparentBackground,
setCookie,
logExample,
basicAuthentication,
}
class SampleMenu extends StatelessWidget {
SampleMenu({
super.key,
required this.webViewController,
});
final WebViewController webViewController;
late final WebViewCookieManager cookieManager = WebViewCookieManager();
@override
Widget build(BuildContext context) {
return PopupMenuButton(
key: const ValueKey('ShowPopupMenu'),
onSelected: (MenuOptions value) {
switch (value) {
case MenuOptions.showUserAgent:
_onShowUserAgent();
case MenuOptions.listCookies:
_onListCookies(context);
case MenuOptions.clearCookies:
_onClearCookies(context);
case MenuOptions.addToCache:
_onAddToCache(context);
case MenuOptions.listCache:
_onListCache();
case MenuOptions.clearCache:
_onClearCache(context);
case MenuOptions.navigationDelegate:
_onNavigationDelegateExample();
case MenuOptions.doPostRequest:
_onDoPostRequest();
case MenuOptions.loadFlutterAsset:
_onLoadFlutterAssetExample();
case MenuOptions.loadHtmlString:
_onLoadHtmlStringExample();
case MenuOptions.transparentBackground:
_onTransparentBackground();
case MenuOptions.setCookie:
_onSetCookie();
case MenuOptions.logExample:
_onLogExample();
case MenuOptions.basicAuthentication:
_promptForUrl(context);
case MenuOptions.loadLocalFile:
// TODO: Handle this case.
}
},
itemBuilder: (BuildContext context) => <PopupMenuItem>[
const PopupMenuItem(
value: MenuOptions.showUserAgent,
child: Text('Show user agent'),
),
const PopupMenuItem(
value: MenuOptions.listCookies,
child: Text('List cookies'),
),
const PopupMenuItem(
value: MenuOptions.clearCookies,
child: Text('Clear cookies'),
),
const PopupMenuItem(
value: MenuOptions.addToCache,
child: Text('Add to cache'),
),
const PopupMenuItem(
value: MenuOptions.listCache,
child: Text('List cache'),
),
const PopupMenuItem(
value: MenuOptions.clearCache,
child: Text('Clear cache'),
),
const PopupMenuItem(
value: MenuOptions.navigationDelegate,
child: Text('Navigation Delegate example'),
),
const PopupMenuItem(
value: MenuOptions.doPostRequest,
child: Text('Post Request'),
),
const PopupMenuItem(
value: MenuOptions.loadHtmlString,
child: Text('Load HTML string'),
),
const PopupMenuItem(
value: MenuOptions.loadLocalFile,
child: Text('Load local file'),
),
const PopupMenuItem(
value: MenuOptions.loadFlutterAsset,
child: Text('Load Flutter Asset'),
),
const PopupMenuItem(
key: ValueKey('ShowTransparentBackgroundExample'),
value: MenuOptions.transparentBackground,
child: Text('Transparent background example'),
),
const PopupMenuItem(
value: MenuOptions.setCookie,
child: Text('Set cookie'),
),
const PopupMenuItem(
value: MenuOptions.logExample,
child: Text('Log example'),
),
const PopupMenuItem(
value: MenuOptions.basicAuthentication,
child: Text('Basic Authentication Example'),
),
],
);
}
Future _onShowUserAgent() {
// Send a message with the user agent string to the Toaster JavaScript channel we registered
// with the WebView.
return webViewController.runJavaScript(
'Toaster.postMessage("User Agent: " + navigator.userAgent);',
);
}
Future _onListCookies(BuildContext context) async {
final String cookies = await webViewController
.runJavaScriptReturningResult('document.cookie') as String;
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Column(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
children: [
const Text('Cookies:'),
_getCookieList(cookies),
],
),
));
}
}
Future _onAddToCache(BuildContext context) async {
await webViewController.runJavaScript(
'caches.open("test_caches_entry"); localStorage["test_localStorage"] = "dummy_entry";',
);
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
content: Text('Added a test entry to cache.'),
));
}
}
Future _onListCache() {
return webViewController.runJavaScript('caches.keys()'
// ignore: missing_whitespace_between_adjacent_strings
'.then((cacheKeys) => JSON.stringify({"cacheKeys" : cacheKeys, "localStorage" : localStorage}))'
'.then((caches) => Toaster.postMessage(caches))');
}
Future _onClearCache(BuildContext context) async {
await webViewController.clearCache();
await webViewController.clearLocalStorage();
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
content: Text('Cache cleared.'),
));
}
}
Future _onClearCookies(BuildContext context) async {
final bool hadCookies = await cookieManager.clearCookies();
String message = 'There were cookies. Now, they are gone!';
if (!hadCookies) {
message = 'There are no cookies.';
}
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Text(message),
));
}
}
Future _onNavigationDelegateExample() {
final String contentBase64 = base64Encode(
const Utf8Encoder().convert(kNavigationExamplePage),
);
return webViewController.loadRequest(
Uri.parse('data:text/html;base64,$contentBase64'),
);
}
Future _onSetCookie() async {
await cookieManager.setCookie(
const WebViewCookie(
name: 'foo',
value: 'bar',
domain: 'httpbin.org',
path: '/anything',
),
);
await webViewController.loadRequest(Uri.parse(
'https://httpbin.org/anything',
));
}
Future _onDoPostRequest() {
return webViewController.loadRequest(
Uri.parse('https://httpbin.org/post'),
method: LoadRequestMethod.post,
headers: {'foo': 'bar', 'Content-Type': 'text/plain'},
body: Uint8List.fromList('Test Body'.codeUnits),
);
}
Future _onLoadFlutterAssetExample() {
return webViewController.loadFlutterAsset('assets/www/index.html');
}
Future _onLoadHtmlStringExample() {
return webViewController.loadHtmlString(kLocalExamplePage);
}
Future _onTransparentBackground() {
return webViewController.loadHtmlString(kTransparentBackgroundPage);
}
Widget _getCookieList(String cookies) {
if (cookies == '""') {
return Container();
}
final List cookieList = cookies.split(';');
final Iterable cookieWidgets =
cookieList.map((String cookie) => Text(cookie));
return Column(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
children: cookieWidgets.toList(),
);
}
Future _onLogExample() {
webViewController
.setOnConsoleMessage((JavaScriptConsoleMessage consoleMessage) {
debugPrint(
'== JS == ${consoleMessage.level.name}: ${consoleMessage.message}');
});
return webViewController.loadHtmlString(kLogExamplePage);
}
Future _promptForUrl(BuildContext context) {
final TextEditingController urlTextController = TextEditingController();
return showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: const Text('Input URL to visit'),
content: TextField(
decoration: const InputDecoration(labelText: 'URL'),
autofocus: true,
controller: urlTextController,
),
actions: [
TextButton(
onPressed: () {
if (urlTextController.text.isNotEmpty) {
final Uri? uri = Uri.tryParse(urlTextController.text);
if (uri != null && uri.scheme.isNotEmpty) {
webViewController.loadRequest(uri);
Navigator.pop(context);
}
}
},
child: const Text('Visit'),
),
],
);
},
);
}
}
class NavigationControls extends StatelessWidget {
const NavigationControls({super.key, required this.webViewController});
final WebViewController webViewController;
@override
Widget build(BuildContext context) {
return Row(
children: [
IconButton(
icon: const Icon(Icons.arrow_back_ios),
onPressed: () async {
if (await webViewController.canGoBack()) {
await webViewController.goBack();
} else {
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('No back history item')),
);
}
}
},
),
IconButton(
icon: const Icon(Icons.arrow_forward_ios),
onPressed: () async {
if (await webViewController.canGoForward()) {
await webViewController.goForward();
} else {
if (context.mounted) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('No forward history item')),
);
}
}
},
),
IconButton(
icon: const Icon(Icons.replay),
onPressed: () => webViewController.reload(),
),
],
);
}
}

最后的效果图：