PowerShell：如何运行文件夹大小总和？

My objective is to write a copy script which moves files from one directory, "d:\aa1", to "d:\aa2" up to a specified size of another directory, "d:\bbb". In other words... I'd like it to copy all files from "d:\aa1" to "d:\aa2" until the size of "d:\aa1" is the same size or less than "d:\bbb".My objective is to write a copy script which mo