Types/OpenPackage/get_FileSize.ps1

<#
.SYNOPSIS
    Gets file content types
.DESCRIPTION
    Gets a table of all files in the package and their associated content types.
#>

$fileLengths = [Ordered]@{}
foreach ($part in  @($this.GetParts())) {
    $partStream = $part.GetStream()
    $fileLengths[$part.Uri] = $partStream.Length
    $partStream.Close()
    $partStream.Dispose()     
}
$fileLengths