Enumerating Powershell NoteProperties

I recently was asked to stuff a custom PSObject into a bunch of key value pairs, so I thought I'd put it here. Is there a better way?

$props = ($File | get-member -MemberType NoteProperty)
foreach( $p in $props )
{
     # write-verbose (invoke-expression "`$File.$($p.Name)")
     $doc.Add( $p.Name, (invoke-expression "`$File.$($p.Name)") )
}