_launchURL() async {
 const url = '要加載的網(wǎng)頁地址';
 if (await canLaunch(url)) {
 await launch(url);
 }
}

Future<bool> launch(
 String urlString, {
 bool forceSafariVC,
 bool forceWebView,
 bool enableJavaScript,
 bool enableDomStorage,
 bool universalLinksOnly,
 Map<String, String> headers,
 Brightness statusBarBrightness,
 }) async {
 assert(urlString != null);
 ........................................

/// [forceSafariVC] is only used in iOS with iOS version >= 9.0. By default (when unset), the launcher
/// opens web URLs in the Safari View Controller, anything else is opened
/// using the default handler on the platform. If set to true, it opens the
/// URL in the Safari View Controller. If false, the URL is opened in the
/// default browser of the phone. Note that to work with universal links on iOS,
/// this must be set to false to let the platform's system handle the URL.
/// Set this to false if you want to use the cookies/context of the main browser
/// of the app (such as SSO flows). This setting will nullify [universalLinksOnly]
/// and will always launch a web content in the built-in Safari View Controller regardless
/// if the url is a universal link or not.

/// [forceWebView] is an Android only setting. If null or false, the URL is
/// always launched with the default browser on device. If set to true, the URL
/// is launched in a WebView. Unlike iOS, browser context is shared across
/// WebViews.

/// [enableJavaScript] is an Android only setting. If true, WebView enable
/// javascript.

/// [enableDomStorage] is an Android only setting. If true, WebView enable
/// DOM storage.

/// [universalLinksOnly] is only used in iOS with iOS version >= 10.0. This setting is only validated
/// when [forceSafariVC] is set to false. The default value of this setting is false.
/// By default (when unset), the launcher will either launch the url in a browser (when the
/// url is not a universal link), or launch the respective native app content (when
/// the url is a universal link). When set to true, the launcher will only launch
/// the content if the url is a universal link and the respective app for the universal
/// link is installed on the user's device; otherwise throw a [PlatformException].

/// [statusBarBrightness] Sets the status bar brightness of the application
/// after opening a link on iOS. Does nothing if no value is passed. This does
/// not handle resetting the previous status bar style.

Future<bool> launch(
 String urlString, {
 bool forceSafariVC,
 bool forceWebView,
 bool enableJavaScript,
 bool enableDomStorage,
 bool universalLinksOnly,
 Map<String, String> headers,
 Brightness statusBarBrightness,
 }) async {
 assert(urlString != null);
 final Uri url = Uri.parse(urlString.trimLeft());
 final bool isWebURL = url.scheme == 'http' || url.scheme == 'https';
 if ((forceSafariVC == true || forceWebView == true) && !isWebURL) {
 throw PlatformException(
 code: 'NOT_A_WEB_SCHEME',
 message: 'To use webview or safariVC, you need to pass'
  'in a web URL. This $urlString is not a web URL.');
 }
 bool previousAutomaticSystemUiAdjustment;
 if (statusBarBrightness != null && defaultTargetPlatform == TargetPlatform.iOS) {
 previousAutomaticSystemUiAdjustment =
 WidgetsBinding.instance.renderView.automaticSystemUiAdjustment;
 WidgetsBinding.instance.renderView.automaticSystemUiAdjustment = true;
 SystemChrome.setSystemUIOverlayStyle(statusBarBrightness == Brightness.light
 ? SystemUiOverlayStyle.dark
 : SystemUiOverlayStyle.light);
 }
 final bool result = await UrlLauncherPlatform.instance.launch(
 urlString,
 useSafariVC: forceSafariVC ?? isWebURL,
 useWebView: forceWebView ?? false,
 enableJavaScript: enableJavaScript ?? false,
 enableDomStorage: enableDomStorage ?? false,
 universalLinksOnly: universalLinksOnly ?? false,
 headers: headers ?? <String, String>{},
 );
 if (statusBarBrightness != null) {
 WidgetsBinding.instance.renderView.automaticSystemUiAdjustment =
 previousAutomaticSystemUiAdjustment;
 }
 return result;
}

if (Platform.isIOS) {
  launch(url, forceSafariVC: false, forceWebView: true);
  return;
 }
 if (Platform.isAndroid) {
  launch(url);
 }

LaunchStatus launch(
 String url,
 Bundle headersBundle,
 boolean useWebView,
 boolean enableJavaScript,
 boolean enableDomStorage) {
 if (activity == null) {
 return LaunchStatus.NO_ACTIVITY;
 }
 
 Intent launchIntent;
 if (useWebView) {
 launchIntent =
  WebViewActivity.createIntent(
  activity, url, enableJavaScript, enableDomStorage, headersBundle);
 } else {
 launchIntent =
  new Intent(Intent.ACTION_VIEW)
  .setData(Uri.parse(url))
  .putExtra(Browser.EXTRA_HEADERS, headersBundle);
 }
 
 activity.startActivity(launchIntent);
 return LaunchStatus.OK;
 }

- (void)launchURLInVC:(NSString *)urlString result:(FlutterResult)result API_AVAILABLE(ios(9.0)) {
 NSURL *url = [NSURL URLWithString:urlString];
 self.currentSession = [[FLTURLLaunchSession alloc] initWithUrl:url withFlutterResult:result];
 __weak typeof(self) weakSelf = self;
 self.currentSession.didFinish = ^(void) {
 weakSelf.currentSession = nil;
 };
 [self.topViewController presentViewController:self.currentSession.safari
     animated:YES
     completion:nil];
}

- (void)launchURL:(NSString *)urlString
  call:(FlutterMethodCall *)call
  result:(FlutterResult)result {
 NSURL *url = [NSURL URLWithString:urlString];
 UIApplication *application = [UIApplication sharedApplication];
 
 if (@available(iOS 10.0, *)) {
 NSNumber *universalLinksOnly = call.arguments[@"universalLinksOnly"] ?: @0;
 NSDictionary *options = @{UIApplicationOpenURLOptionUniversalLinksOnly : universalLinksOnly};
 [application openURL:url
   options:options
 completionHandler:^(BOOL success) {
  result(@(success));
 }];
 } else {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
 BOOL success = [application openURL:url];
#pragma clang diagnostic pop
 result(@(success));
 }
}

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
 <base-config cleartextTrafficPermitted="true">
 <trust-anchors>
  <certificates src="system" />
 </trust-anchors>
 </base-config>
</network-security-config>
///IOS：