https://docs.microsoft.com/zh-cn/visualstudio/install/create-an-offline-installation-of-visual-studio?view=vs-2019，微软官方的讲述。
如果要证书：https://docs.microsoft.com/zh-cn/visualstudio/install/install-certificates-for-visual-studio-offline?view=vs-2019
对应ID-企业版：https://docs.microsoft.com/zh-cn/visualstudio/install/workload-component-id-vs-enterprise?view=vs-2019
对应ID-专业版：https://docs.microsoft.com/zh-cn/visualstudio/install/workload-component-id-vs-professional?view=vs-2019
对应ID-社区免费版：https://docs.microsoft.com/zh-cn/visualstudio/install/workload-component-id-vs-community?view=vs-2019