Note that some of this tip applies to including any external library for use in custom code. Recommendations

注意该提示的一些部分将应用于引入定制代码中所使用的任何外部库。

youdao

If the custom code is generic and can be used in other projects, then putting it in a library may be a better option than a project specific second source folder.

如果定制代码是一般化的并被应用于其他项目，那么比起放入特定项目的次级源文件夹，将其放入库中是个更好的选择。

youdao