powershell获取windows子文件夹的大小

 $startFolder = "E:\Migration\"
 $colItems = (Get-ChildItem $startFolder | Where-Object {$_.PSIsContainer -eq $True} | Sort-Object)
 foreach ($i in $colItems)
 {
  $subFolderItems = (Get-ChildItem $i.FullName -recurse | Measure-Object -property length -sum)
  $FileSize="{0:N2}" -f ($subFolderItems.sum / 1GB)
  $Unit='GB'
  if($FileSize -lt 1)
  {
   $FileSize="{0:N2}" -f ($subFolderItems.sum / 1MB)
   $Unit='MB'
  }
  write-host $i.FullName ' -- ' $FileSize $Unit -fore green
 }

计算速度很快，只需修改$startFolder变量即可。