我有同样的问题，Visual Studio代码不能在它的内置终端中运行任何ng命令。

我添加了%AppData%\npm到Windows 10的路径中，并且不需要重新启动，只是关闭和重新打开VS Code，它看不到它。

I was having the same issue when tried with the syntax "ng new " and solved that simply by updating the existing node version from 5.x.x to 8.x.x. After successful updation of node, the syntax worked perfectly for me. Please update the existing version of node. As it is clearly mentioned in angular documentation that these commands require the node version >= 6.9.x. For reference please check https://angular.io/guide/quickstart. It clearly states "Verify that you are running at least node 6.9.x and npm 3.x.x by running node -v and npm -v in a terminal/console window. Older versions produce errors, but newer versions are fine".

今天我也遇到了同样的问题，我走过了下面这条路—— (%USERPROFILE%\AppData\Roaming\npm)，当我清除npm目录下的所有内容时，才知道有一些垃圾数据。现在当我运行(npm安装命令再次)。现在一切正常。

设置路径= % %路径;C: \ \ \ AppData \ \ npm漫游用户

执行以下几行，以解决ng未找到和未定义版本的问题

卸载-g angular-cli

卸载angular-cli

NPM缓存清理

安装-g @angular/cli@latest

您可以这样办理登机手续。我也有同样的问题。首先，在环境变量中检查用户PATH。它必须指向%USERPROFILE%\AppData\Roaming\npm\node_modules\@angular\cli\

使用node.js命令提示符代替命令提示符。在安装的程序菜单中运行node.js命令提示符。点击开始，搜索node.js命令提示符。运行它，然后输入ng -v回车。它会起作用的。如果有帮助，请告诉我。