先看效果图

WechatIMG306.jpeg

然后是代码

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:wanandroid/utils/ScreenUtils.dart';
import 'package:webview_flutter/webview_flutter.dart';

class WebViewBrowser extends StatefulWidget{

  @override
  _WebViewBrowserState createState() {
    return _WebViewBrowserState();
  }
}

class _WebViewBrowserState extends State<WebViewBrowser>{

  /// 当前页的标题
  String _title = "";
  /// 获取当前标题
  void _getNavTitle() async {
    _title = _webViewController!=null ? await _webViewController.getTitle():"";
  }
  /// WebViewController对象
  WebViewController _webViewController;
  /// 页面加载结束
  bool _loadingEnded = true;
  /// 是否可以返回
  bool _canGoBack = false;
  /// 操作面板按钮
  IconButton _shareButton;


  @override
  void initState() {
    super.initState();

    _loadingEnded = true;
    _canGoBack = false;
    /// 根据加载状态显示分享按钮还是进度提示
    _shareButton = IconButton(icon: Icon(Icons.more_horiz_rounded), onPressed: (){
      _operationAction();
    });
  }

  @override
  Widget build(BuildContext context) {

    var _url = (ModalRoute.of(context).settings.arguments).toString() ?? "https://www.baidu.com";

    return Scaffold(
      appBar: AppBar(
        brightness: Brightness.dark,
        automaticallyImplyLeading: true,
        toolbarHeight: Screen.navigationBarHeight,
        elevation: 1,
        title: _loadingEnded?Text(_title,style: TextStyle(fontSize: 14),maxLines: 2):CupertinoActivityIndicator(),
        centerTitle: false,
        leadingWidth: 54,
        /// 返回按键
        leading: IconButton(icon: Icon(Icons.arrow_back), onPressed: () async {
          if(_canGoBack == true){
            _webViewController.goBack();
          }else{
            if(Navigator.canPop(context)){ Navigator.pop(context); }
          }
        }),
        /// 分享按钮和关闭按钮
        actions: _canGoBack==true?[
          //关闭当前页面
          IconButton(icon: Icon(Icons.close), onPressed: (){
            if(Navigator.canPop(context)){ Navigator.pop(context); }
          }),
          // 弹出操作面板
          _shareButton
        ]:[ _shareButton ]
      ),
      body: WebView(
        initialUrl: _url,
        javascriptMode: JavascriptMode.unrestricted,
        gestureNavigationEnabled: true,
        debuggingEnabled: true,
        onWebViewCreated: (webViewController)async{
          _webViewController = webViewController;
          _loadingEnded = false;
          _canGoBack = await _webViewController.canGoBack();
          _getNavTitle();
          setState(() {
          });
        },
        onPageStarted: (currentUrl)async{
          _loadingEnded = false;
          _title = currentUrl;
          _canGoBack = await _webViewController.canGoBack();
          _getNavTitle();
          setState(() {
          });
        },
        onPageFinished: (currentUrl) async{
          _loadingEnded = true;
          _canGoBack = await _webViewController.canGoBack();
          _getNavTitle();
          setState(() {
          });
        },
        onWebResourceError: (error){
          _title = error.description;
          setState(() {
          });
        },
        navigationDelegate: (delegate){
          // if (delegate.url.startsWith('alipay:') ||
          //     delegate.url.startsWith('weixin:')) {
          //   return NavigationDecision.prevent;
          // }
          return NavigationDecision.navigate;
        },
      ),
    );
  }

  @override
  void dispose() {
    super.dispose();
  }

  /// 在这里显示操作面板
  void _operationAction(){

  }
}

Flutter小白欢迎各位大佬进行指教，谢谢了。