Webpack报错:Error: Cannot resolve module 'style-loader'

1.安装style-loader  cssl-loader

npm install style-loader --save-dev
npm install css-loader --save-dev
2.webpack.config.js上面加上resolve

resolve: {
extensions: ['.js','.css']
}

完整一点的
module: {
rules:[
{
test: /\.js$/, // js结尾的文件
// exclude: /node_modules/,
use: 'babel-loader?presets[]=es2015',
exclude:[ //忽略掉下面的文件 不进行检测
path.resolve(__dirname,'../node_modules')
]
},
{
test: /\.css$/,
use: ExtractTextPlugin.extract({
fallback: "style-loader",
use: "css-loader"
})
}
]
},
resolve: {
extensions: ['.js','.css']
},