Flutter：如何使用WebView插件

比眉伴天荒 2022-11-27 04:27 289阅读 0赞

Displaying webpages inside of your Flutter applications is easy with the use of the `WebView` plugin. In our example application, we’ll look at how to create a custom `Widget` that can be used throughout our application to launch a `WebView` from anywhere.

显示网页的颤振应用中很容易与使用的`WebView`插件。 在示例应用程序中，我们将研究如何创建可在整个应用程序中使用的自定义`Widget` ，以便从任何地方启动`WebView` 。

## 创建一个新的Flutter项目 **(**Creating a new Flutter Project**)** ##

As always, we’ll start off by setting up a new project and adding the plugin:

与往常一样，我们将从建立一个新项目并添加插件开始：

# New Flutter project
    $ flutter create my_webview_project
    
    # Open this up inside of VS Code
    $ cd my_webview_project && code .

## 添加WebView插件 **(**Adding the WebView plugin**)** ##

Next up, we’ll need to add the `webview_flutter` plugin within our `pubspec.yaml`:

接下来，我们需要添加`webview_flutter`我们中的插件`pubspec.yaml` ：

dependencies:
      flutter:
        sdk: flutter
      webview_flutter: ^0.3.14+1

We’ll then need to add the appropriate values to our `Info.plist`, opting into the embedded views preview:

然后，我们需要将适当的值添加到`Info.plist` ，以选择嵌入的视图预览：

<key>io.flutter.embedded_views_preview</key>
    <true/>

That’s all the required plugin preparation, we can now open our application up in the iOS or Android simulator.

这就是所有必要的插件准备工作，我们现在可以在iOS或Android模拟器中打开应用程序。

## 脚手架我们的项目 **(**Scaffolding our Project**)** ##

We can now update `main.dart` to contain our `HomePage` widget that we’ll create in a second:

现在，我们可以更新`main.dart`包含我们的`HomePage`小工具，我们将在第二个创建：

import 'package:flutter/material.dart';
    import 'package:my_webview_project/home_page.dart';
    
    void main() => runApp(MyApp());
    
    class MyApp extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
            title: 'Flutter WebView',
            theme: ThemeData(
              primarySwatch: Colors.blue,
            ),
            home: HomePage());
      }
    }

The `HomePage` widget will simply consist of a `FlatButton` with an `onPressed` event:

该`HomePage`部件将仅包括一个的`FlatButton`与`onPressed`事件：

import 'package:flutter/material.dart';
    
    class HomePage extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(
            title: Text("Home Page"),
          ),
          body: Center(
            child: FlatButton(
              child: Text("Open Webpage"),
              onPressed: () {},
            ),
          ),
        );
      }
    }

## 使用WebView插件 **(**Using the WebView Plugin**)** ##

Let’s create a `StatelessWidget` named `MyWebView` which we can use to navigate a user to this page whenever we want to display `WebView` data:

让我们创建一个`StatelessWidget`名为`MyWebView`我们可以用它来用户导航到该页面时，我们要显示`WebView`数据：

import 'dart:async';
    import 'package:flutter/material.dart';
    
    import 'package:webview_flutter/webview_flutter.dart';
    
    class MyWebView extends StatelessWidget {
      final String title;
      final String selectedUrl;
    
      final Completer<WebViewController> _controller =
          Completer<WebViewController>();
    
      MyWebView({
        @required this.title,
        @required this.selectedUrl,
      });
    
      @override
      Widget build(BuildContext context) {
        return Scaffold(
            appBar: AppBar(
              title: Text(title),
            ),
            body: WebView(
              initialUrl: selectedUrl,
              javascriptMode: JavascriptMode.unrestricted,
              onWebViewCreated: (WebViewController webViewController) {
                _controller.complete(webViewController);
              },
            ));
      }
    }

If we wanted to navigate the user to `https://alligator.io`, we could therefore use `Navigator.push` with the `selectedUrl` equal to `https://alligator.io`. Let’s update our `FlatButton` within the `HomePage`:

如果我们想将用户导航到`https://alligator.io` ，则可以使用`Navigator.push` ，并且`selectedUrl`等于`https://alligator.io` 。 让我们在`HomePage`更新`FlatButton` ：

child: FlatButton(
      child: Text("Open Webpage"),
      onPressed: () {
        Navigator.of(context).push(MaterialPageRoute(
            builder: (BuildContext context) => MyWebView(
                  title: "Alligator.io",
                  selectedUrl: "https://alligator.io",
                )));
      },
    ),

And there we have it! Here’s our `WebView` showing the Alligator homepage:

我们终于得到它了！ 这是我们的`WebView`显示了鳄鱼主页：

> 翻译自: [https://www.digitalocean.com/community/tutorials/flutter-webview][https_www.digitalocean.com_community_tutorials_flutter-webview]

[https_www.digitalocean.com_community_tutorials_flutter-webview]: https://www.digitalocean.com/community/tutorials/flutter-webview