解决vue打包css文件中背景图片的路径问题

.welcome { width: 420px; height: 235px; background: url(../img/welcome.jpg) 0 0 no-repeat;

// Extract CSS when that option is specified
 // (which is the case during production build)
 if (options.extract) {
  return ExtractTextPlugin.extract({
  use: loaders,
  fallback: 'vue-style-loader',
  publicPath:'../../'   //添加此代码！！！
  })
 } else {
  return ['vue-style-loader'].concat(loaders)
 }