使用包：http/browser\u client.dart会导致有关镜像的警告

在dart

import'包中执行以下导入：http/browser_client.dart'在执行发布构建时引发警告

****************************************************************
* WARNING: dart:mirrors support in dart2js is experimental,
*          and not recommended.
*          This implementation of mirrors is incomplete,
*          and often greatly increases the size of the generated
*          JavaScript code.
*
* Your app imports dart:mirrors via:
*   index.html_bootstrap.dart => package:myapp => package:http => dart:mirrors
*
* Starting with Dart 1.9, you must use the
* --enable-experimental-mirrors command-line flag to opt-in.
* You can begin using this flag now if mirrors support is critical.
*
* To learn what to do next, please visit:
*    http://dartlang.org/dart2js-reflection
****************************************************************

[Warning from Dart2JS on myapp|web/index.html_bootstrap.dart]:
3 hint(s) suppressed in package:http.
[Dart2JS on myapp|web/index.html_bootstrap.dart]:
5 warning(s) suppressed in package:myapp.
[Warning from Dart2JS]:
web/index.html_bootstrap.dart:
1 methods retained for use by dart:mirrors out of 2361 total methods (0%).
[Info from Dart2JS on myapp|web/index.html_bootstrap.dart]:
packages/http/src/io.dart:9:1:
Import of 'dart:mirrors'.
import 'dart:mirrors';
^^^^^^^^^^^^^^^^^^^^^^

使用该浏览器\u客户端的代码是：

var client = new BrowserClient();
client.post(url, body: req.toString())...

这是我应该关心的事情吗，或者这是一个讨厌的警告，除非我停止使用http包，否则它不会消失吗

更新：

查看browser_client.dart内部，我看到以下评论：

// TODO(nweiz): Move this under src/, re-export from lib/http.dart, and use this
// automatically from [new Client] once we can create an HttpRequest using
// mirrors on dart2js (issue 18541) and dart2js doesn't crash on pkg/collection
// (issue 18535).

更新：

运行pub help时，我没有看到这样的标志：

pub help
Pub is a package manager for Dart.

Usage: pub <command> [arguments]

Global options:
-h, --help            Print this usage information.
    --version         Print pub version.
    --[no-]trace      Print debugging information when an error occurs.
    --verbosity       Control output verbosity.

          [all]       Show all output including internal tracing messages.
          [io]        Also show IO operations.
          [normal]    Show errors, warnings, and user messages.
          [solver]    Show steps during version resolution.

-v, --verbose         Shortcut for "--verbosity=all".

Available commands:
  build       Apply transformers to build a package.
  cache       Work with the system cache.
  deps        Print package dependencies.
  downgrade   Downgrade the current package's dependencies to oldest versions.
  get         Get the current package's dependencies.
  global      Work with global packages.
  help        Display help information for Pub.
  publish     Publish the current package to pub.dartlang.org.
  run         Run an executable from a package.
  serve       Run a local web development server.
  upgrade     Upgrade the current package's dependencies to latest versions.
  uploader    Manage uploaders for a package on pub.dartlang.org.
  version     Print pub version.

 pub build --enable-experimental-mirrors
Could not find an option named "enable-experimental-mirrors".

当您添加它告诉您添加的标志时，它将消失：
--启用实验镜像

正如消息所说，镜像当前膨胀到生成的JavaScript的大小。这常常会让开发人员措手不及，因为他们理所当然地希望dart2js能够正确处理这一问题。然而，这对于dart2js来说是一个非常重要的问题。虽然正在开发更好的解决方案，但镜像支持被认为是实验性的，此警告用于通知开发人员使用它们可能涉及的问题

您可以添加该标志，表示您已意识到镜像问题，并选择使用它们。
我使用的是dart 1.8.3，当我执行
pub build时，该标志不可用。
请尝试通过您的pubspec启用它，因为它修复了镜像问题，谢谢！我会尽量避免使用镜像，直到它不再是一个实验性的特性。实际上，这并不能解决真正的问题。当已经导入浏览器客户端IMHO时，强制使用镜像检查“IOClient”是否可用是错误的，并导致镜像出现问题。我认为这实际上是应该报告的
http
包的问题。