below is the css code
.loaderActive {
position: relative;
overflow: hidden;
&:after {
position: absolute;
top: 0%;
left: 0%;
content: "";
width: 100%;
height: 100%;
background-color: rgba(0, 0, 0, 0.2);
background-image:url("../lib/images/loader.apng");
background-repeat: no-repeat;
background-position: center;
}
}
但是在使用npm install构建之后
background-image：url（“ ../ lib / images / loader.apng”）;正在转换为 background-image：url（../../ static / media / loader.21688046.apng）
请提出解决方案
下面是webpack.config.dev.js
// @删除开始 / ** *版权所有（c）2015年至今，Facebook，Inc.。 * 版权所有。 * *此源代码根据BSD样式许可获得许可，该许可可在 *此源树的根目录中的LICENSE文件。额外补助 *专利权的*可在同一目录的PATENTS文件中找到。 * / // @ remove-on-eject-end
'use strict';
var autoprefixer = require('autoprefixer');
var webpack = require('webpack');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
var WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
var getClientEnvironment = require('./env');
var paths = require('./paths');
// @remove-on-eject-begin
// `path` is not used after eject - see https://github.com/facebookincubator/create-react-app/issues/1174
var path = require('path');
// @remove-on-eject-end
// Webpack uses `publicPath` to determine where the app is being served from.
// In development, we always serve from the root. This makes config easier.
var publicPath = '/';
// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
var publicUrl = '';
// Get environment variables to inject into our app.
var env = getClientEnvironment(publicUrl);
// This is the development configuration.
// It is focused on developer experience and fast rebuilds.
// The production configuration is different and lives in a separate file.
module.exports = {
// You may want 'eval' instead if you prefer to see the compiled output in DevTools.
// See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
devtool: 'cheap-module-source-map',
// These are the "entry points" to our application.
// This means they will be the "root" imports that are included in JS bundle.
// The first two entry points enable "hot" CSS and auto-refreshes for JS.
entry: [
// Include an alternative client for WebpackDevServer. A client's job is to
// connect to WebpackDevServer by a socket and get notified about changes.
// When you save a file, the client will either apply hot updates (in case
// of CSS changes), or refresh the page (in case of JS changes). When you
// make a syntax error, this client will display a syntax error overlay.
// Note: instead of the default WebpackDevServer client, we use a custom one
// to bring better experience for Create React App users. You can replace
// the line below with these two lines if you prefer the stock client:
// require.resolve('webpack-dev-server/client') + '?/',
// require.resolve('webpack/hot/dev-server'),
require.resolve('react-dev-utils/webpackHotDevClient'),
// We ship a few polyfills by default:
require.resolve('./polyfills'),
// Finally, this is your app's code:
paths.appIndexJs
// We include the app code last so that if there is a runtime error during
// initialization, it doesn't blow up the WebpackDevServer client, and
// changing JS code would still trigger a refresh.
],
output: {
// Next line is not used in dev but WebpackDevServer crashes without it:
path: paths.appBuild,
// Add /* filename */ comments to generated require()s in the output.
pathinfo: true,
// This does not produce a real file. It's just the virtual path that is
// served by WebpackDevServer in development. This is the JS bundle
// containing code from all our entry points, and the Webpack runtime.
filename: 'static/js/bundle.js',
// This is the URL that app is served from. We use "/" in development.
publicPath: publicPath
},
resolve: {
// This allows you to set a fallback for where Webpack should look for modules.
// We read `NODE_PATH` environment variable in `paths.js` and pass paths here.
// We use `fallback` instead of `root` because we want `node_modules` to "win"
// if there any conflicts. This matches Node resolution mechanism.
// https://github.com/facebookincubator/create-react-app/issues/253
fallback: paths.nodePaths,
// These are the reasonable defaults supported by the Node ecosystem.
// We also include JSX as a common component filename extension to support
// some tools, although we do not recommend using it, see:
// https://github.com/facebookincubator/create-react-app/issues/290
extensions: ['.js', '.json', '.jsx', ''],
alias: {
// Support React Native Web
// https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
'react-native': 'react-native-web'
}
},
// @remove-on-eject-begin
// Resolve loaders (webpack plugins for CSS, images, transpilation) from the
// directory of `react-scripts` itself rather than the project directory.
resolveLoader: {
root: paths.ownNodeModules,
moduleTemplates: ['*-loader']
},
// @remove-on-eject-end
module: {
// First, run the linter.
// It's important to do this before Babel processes the JS.
preLoaders: [
{
test: /\.(js|jsx)$/,
loader: 'eslint',
include: paths.appSrc,
}
],
loaders: [
// ** ADDING/UPDATING LOADERS **
// The "url" loader handles all assets unless explicitly excluded.
// The `exclude` list *must* be updated with every change to loader extensions.
// When adding a new loader, you must add its `test`
// as a new entry in the `exclude` list for "url" loader.
// "url" loader embeds assets smaller than specified size as data URLs to avoid requests.
// Otherwise, it acts like the "file" loader.
{
exclude: [
/\.html$/,
// We have to write /\.(js|jsx)(\?.*)?$/ rather than just /\.(js|jsx)$/
// because you might change the hot reloading server from the custom one
// to Webpack's built-in webpack-dev-server/client?/, which would not
// get properly excluded by /\.(js|jsx)$/ because of the query string.
// Webpack 2 fixes this, but for now we include this hack.
// https://github.com/facebookincubator/create-react-app/issues/1713
/\.(js|jsx)(\?.*)?$/,
/\.css$/,
/\.json$/,
/\.gif$/
],
loader: 'url',
query: {
limit: 10000,
name: 'static/media/[name].[hash:8].[ext]'
}
},
// Process JS with Babel.
{
test: /\.(js|jsx)$/,
include: paths.appSrc,
loader: 'babel',
query: {
// @remove-on-eject-begin
babelrc: false,
presets: [require.resolve('babel-preset-react-app')],
// @remove-on-eject-end
// This is a feature of `babel-loader` for webpack (not Babel itself).
// It enables caching results in ./node_modules/.cache/babel-loader/
// directory for faster rebuilds.
cacheDirectory: true
}
},
// "postcss" loader applies autoprefixer to our CSS.
// "css" loader resolves paths in CSS and adds assets as dependencies.
// "style" loader turns CSS into JS modules that inject <style> tags.
// In production, we use a plugin to extract that CSS to a file, but
// in development "style" loader enables hot editing of CSS.
{
test: /\.css$/,
loader: 'style!css?importLoaders=1!postcss'
},
// JSON is not enabled by default in Webpack but both Node and Browserify
// allow it implicitly so we also enable it.
{
test: /\.json$/,
loader: 'json'
},
// "file" loader for svg
{
test: /\.gif$/,
loader: 'file',
query: {
name: '../img/[name].[ext]'
}
}
// ** STOP ** Are you adding a new loader?
// Remember to add the new extension(s) to the "url" loader exclusion list.
]
},
// @remove-on-eject-begin
// Point ESLint to our predefined config.
eslint: {
configFile: path.join(__dirname, '../eslintrc'),
useEslintrc: false,
},
// @remove-on-eject-end
// We use PostCSS for autoprefixing only.
postcss: function() {
return [
autoprefixer({
browsers: [
'>1%',
'last 4 versions',
'Firefox ESR',
'not ie < 9', // React doesn't support IE8 anyway
]
}),
];
},
plugins: [
// Makes some environment variables available in index.html.
// The public URL is available as %PUBLIC_URL% in index.html, e.g.:
// <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
// In development, this will be an empty string.
new InterpolateHtmlPlugin(env.raw),
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
}),
// Makes some environment variables available to the JS code, for example:
// if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
new webpack.DefinePlugin(env.stringified),
// This is necessary to emit hot updates (currently CSS only):
new webpack.HotModuleReplacementPlugin(),
// Watcher doesn't work well if you mistype casing in a path so we use
// a plugin that prints an error when you attempt to do this.
// See https://github.com/facebookincubator/create-react-app/issues/240
new CaseSensitivePathsPlugin(),
// If you require a missing module and then `npm install` it, you still have
// to restart the development server for Webpack to discover it. This plugin
// makes the discovery automatic so you don't have to restart.
// See https://github.com/facebookincubator/create-react-app/issues/186
new WatchMissingNodeModulesPlugin(paths.appNodeModules)
],
// Some libraries import Node modules but don't use them in the browser.
// Tell Webpack to provide empty mocks for them so importing them works.
node: {
fs: 'empty',
net: 'empty',
tls: 'empty'
}
};