npm install webpack报错if you are behind a proxy,please make sure that the proxy cinfig is setproperly

npm install webpack -g报错if you are behind a proxy,please make sure that the 'proxy' cinfig is set properly.

错误信息提示：若配置了代理，请确认代理被合理配置。因此去设置npm代理
执行npm config set proxy http://proxy.example.com:8080
参考https://qiita.com/tenten0213/items/7ca15ce8b54acc3b5719

然后重新执行npm install webpack -g，又报错

提示：服务器出错，重新配置npm镜像地址
执行npm config set registry http://registry.npmjs.org/
终于，webpack安装成功了。