运行vue项目，显示“npm”无法识别为 cmdlet、函数、脚本文件或可操作程序的名称

PS D:\weduproject\wedu1\wedu\wedu-fast-vue> npm run dev，运行时出现像下面这样的报红信息，

npm : The term 'npm' is not recognized as the name of a cmdlet, function, script file, or operable program. Check
 the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ npm run dev
+ ~~~
    + CategoryInfo          : ObjectNotFound: (npm:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

原因：没有使用管理员打开vscode，使用管理员打开vscode就可以了。