Flutter WebView的三种类型打开方式

由于在国内flutter应该还不是很广泛了，我在找这三种打开方式的时候费了九牛二虎之力了，各种百度各种谷歌，然后github，也只能找到某一类型的打开方式，所以耗费了好长时间了，所以写这篇文章的目的是帮助一写有需要的人节省一点时间了，有的时候感觉时间耗费在这些问题上感觉不值上了，从iOS转到flutter开发，用的android studio开发了，估计是刚用吧，感觉遇到的问题千奇百怪了，比起Xcode不好用，咱也不敢说了，毕竟咱才用了一段时间.

1：在pubspec.yaml添加依赖库

dependencies:
  webview_flutter: ^0.3.8
  flutter_html: ^0.9.6

2:ios中在ios/Runner/Info.plist中添加

<key>io.flutter.embedded_views_preview</key>
<string>YES</string>*

3:android中需要添加网络权限（图1，没有则添加）

<uses-permission android:name="android.permission.INTERNET" />

如果上面步骤完成

1:打开本地HTML

import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';
import 'package:flutter/services.dart';
import 'dart:convert';

class LocalWebViewController extends StatelessWidget {

  WebViewController _webViewController;
  String filePath = "data/user_protocol.html";

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("本地html"),
      ),
      body: Container(
        child: WebView(
          initialUrl: "",
          javascriptMode: JavascriptMode.unrestricted,
          onWebViewCreated: ((WebViewController vc){
            _webViewController = vc;
            _loadlocalData();
          }),
        ),
      ),
    );
  }
  _loadlocalData() async {
    String fileHtmlContents = await rootBundle.loadString(filePath);
    _webViewController.loadUrl(Uri.dataFromString(fileHtmlContents,
        mimeType: 'text/html', encoding: Encoding.getByName('utf-8'))
        .toString());
  }
}

2:打开URL连接

import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';
import 'package:flutter/services.dart';
import 'package:flutter/cupertino.dart';

class URLWebViewController extends StatelessWidget {

  CupertinoActivityIndicator _indicator;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("web url"),
      ),
      body: Container(
        child: WebView(
          initialUrl: "https://juejin.cn/user/958429869910686",
          javascriptMode: JavascriptMode.unrestricted,
          onPageFinished: (url){
            print(url);
          },
          onWebViewCreated: (vc){

          },
        ),
      ),
    );
  }
}

3:打开HTML

import 'package:flutter/material.dart';
import 'package:flutter_html/flutter_html.dart';
import 'package:dio/dio.dart';

class HTMLWebViewController extends StatefulWidget {
  @override
  _HTMLWebViewControllerState createState() => _HTMLWebViewControllerState();
}

class _HTMLWebViewControllerState extends State<HTMLWebViewController> {

  String content;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _loadData();
  }

  @override
  Widget build(BuildContext context) {

    if(content == null) {
      return Scaffold(
        appBar: AppBar(
          title: Text("加载HTML"),
        ),
        body: Container(),
      );
    }

    return Scaffold(
      appBar: AppBar(
        title: Text("加载HTML"),
      ),
      body: SingleChildScrollView(
        scrollDirection: Axis.vertical,
        reverse: false,
        padding: EdgeInsets.all(0),
        child: Html(data: content),
      ),
    );
  }


  _loadData() async {
    Map<String, dynamic> params = {"id": "2202"};
    String url = "http://47.110.124.138:8081/stock/api/newsdetail/";

    Response response;
    response = await Dio().get(url, queryParameters: params);
    setState(() {
      content = response.data["data"]["content"];
    });
  }
}

在运行的安卓环境时候遇到一个错误

NDK is missing a "platforms" directory.

解决办法：谷歌了一下说是没有安装什么ndk(mac 环境下)

1:找到如图画黑色小圈的地方点击

按照如图步骤执行，等待安装成功就可以了

Flutter WebView的三种类型 打开方式

Flutter WebView的三种类型打开方式