问题

VSCode安装插件时，报了这么一个错：Error while fetching extensions : XHR failed

解决办法

1. 找到host文件：C:\Windows\System32\drivers\etc\hosts
2. 打开host文件：右键->打开方式->用记事本打开
3. 修改host文件：在host文件下面添加下面内容

# VSCode
20.43.132.130  update.code.visualstudio.com   # Visual Studio Code download and update server
13.69.68.34  code.visualstudio.com   # Visual Studio Code documentation
104.119.90.120  go.microsoft.com    #  Microsoft link forwarding service
20.150.83.4  vscode.blob.core.windows.net    # Visual Studio Code blob storage, used for remote server
13.107.42.18 marketplace.visualstudio.com    # Visual Studio Marketplace
191.238.172.191 *.gallery.vsassets.io    # Visual Studio Marketplace
191.238.172.191 *.gallerycdn.vsassets.io     # Visual Studio Marketplace
40.70.164.17 rink.hockeyapp.net      # Crash reporting service
13.75.34.168 bingsettingssearch.trafficmanager.net   # In-product settings search
138.91.148.66 vscode.search.windows.net    # In-product settings search
raw.githubusercontent.com       # GitHub repository raw file access
50.17.211.206 vsmarketplacebadge.apphb.com    # Visual Studio Marketplace badge service
117.18.232.200 az764295.vo.msecnd.net    # Visual Studio Code download CDN
42.80.217.156 download.visualstudio.microsoft.com  # Visual Studio download server, provides dependencies for some VS Code extensions (C++, C#)
13.67.9.5 vscode-sync.trafficmanager.net     # Visual Studio Code Settings Sync service
13.69.68.64  vscode-sync-insiders.trafficmanager.net  # Visual Studio Code Settings Sync service (Insiders)
13.107.5.93 default.exp-tas.com     #  Visual Studio Code Experiment Service, used to provide experimental user experiences

4.  保存host文件：需要管理员权限

5.  刷新DNS缓存：在cmd中执行命令：ipconfig /flushdns

6.  重启VSCode：点击安装插件即可