html - 避免在Flutter Web插件包之外使用仅Web库

Question

我正在构建一个Flutter应用，试图在网络上工作。其中一部分包含一些特定于网络的代码:

import 'dart:html' as html;
import 'package:flutter/foundation.dart';

class DownloadViewModel extends ChangeNotifier {
  static const String url = 'https://example.com/api/v1/app/myapp_1.0.0.apk';
  void onAndroidDownloadPressed() {
    html.window.open(url, 'AndroidApp');
  }
}

但是，dart:html导入会出现以下错误:

Avoid using web-only libraries outside Flutter web plugin packages

警告的较长版本如下所示:

Avoid using web libraries, dart:html, dart:js and dart:js_util in Flutter packages that are not web plugins. These libraries are not supported outside a web context; functionality that depends on them will fail at runtime in Flutter mobile, and their use is generally discouraged in Flutter web.

Web library access is allowed in:

plugin packages that declare web as a supported context

otherwise, imports of dart:html, dart:js and dart:js_util are disallowed.

这不仅是警告。这实际上阻止了构建Android或iOS应用程序(即使非Web Flutter应用程序无法访问此方法)。

我发现的唯一解决方案是在为Android和iOS构建时注释掉导入，然后在为Web构建时取消注释。有更好的解决方案吗？

Answer 1

使用universal_html软件包。它支持浏览器，Dart VM和Flutter，并且是dart:html和其他与Web相关的库的替代品。

dependencies:
  universal_html: ^1.2.1

然后，可以使用以下导入来代替import 'dart:html' as html;:

import 'package:universal_html/html.dart' as html;

对于那些因其他相关的Web导入问题(例如dart:js)而来到此页面的人，此插件还支持以下导入:

import 'package:universal_html/driver.dart';
import 'package:universal_html/html.dart';
import 'package:universal_html/indexed_db.dart';
import 'package:universal_html/js.dart';
import 'package:universal_html/js_util.dart';
import 'package:universal_html/prefer_sdk/html.dart';
import 'package:universal_html/prefer_sdk/indexed_db.dart';
import 'package:universal_html/prefer_sdk/js.dart';
import 'package:universal_html/prefer_sdk/js_util.dart';
import 'package:universal_html/prefer_sdk/svg.dart';
import 'package:universal_html/prefer_sdk/web_gl.dart';
import 'package:universal_html/prefer_universal/html.dart';
import 'package:universal_html/prefer_universal/indexed_db.dart';
import 'package:universal_html/prefer_universal/js.dart';
import 'package:universal_html/prefer_universal/js_util.dart';
import 'package:universal_html/prefer_universal/svg.dart';
import 'package:universal_html/prefer_universal/web_gl.dart';
import 'package:universal_html/svg.dart';
import 'package:universal_html/web_gl.dart';