图解VS 2017升级并安装.NET Core 2.1 SDK
https://jingyan.baidu.com/album/ff42efa9fb5816c19e2202ef.html?picindex=2
vs2017安装和使用教程（详细）
https://blog.csdn.net/qq_36556893/article/details/79430133
Visual Studio 2017各版本安装包离线下载、安装全解析
https://www.ithome.com/html/win10/297093.htm
VS2017专业版和企业版激活密钥
Enterprise:
NJVYC-BMHX2-G77MM-4XJMR-6Q8QF
Professional:
KBJFW-NXHK6-W4WJM-CRMQB-G3CDH