Why doesn't the PowerShell, cmdletbinding, command work incorrectly?

The CmdletBinding attribute is an attribute of functions that makes them operate like compiled cmdlets

#
# NAME: Ref48Step1GetRemoteGroupMembers.ps1
#
# Modified: IT Staff
# Date: 03-Feb-2015
#Requires -Version 4.0
# Client OS: Windows 7, Server OS: Windows 2008 R2
#
# DESCRIPTION:
# Supply this function with an Active Directory local groups members
#
# Assumes the presence of Microsoft's ActiveDirectory PowerShell module.
# ==============================================================================================
<#
 .Synopsis
  Gets membership information of remote computer groups

 .Description
  This script by default queries the membership details of local administrators group on remote computers
  It has a provision to query any local group in remote server, not just administrators group
 
 .Parameter ComputerName - $ComputerName = $env:ComputerName
  Computer Name(s) which you want to query for local group information
 
 .Parameter RemoteGroupName - $RemoteGroupName = "Administrators",
  Name of the remote group which you want to query for membership information. It queries 'Administrators' group when
  this parameter is not specified
 
 .Parameter OutputDir - $OutputDir = "c:\Scripts"
  Name of the folder where you want to place the output file. It creates the output file in c:\Scripts folder.
 
 .Example - option 1
  Ref48Step1GetRemoteGroupMembers.ps1
  Queries the local administrators group membership and writes the details to c:\Scripts\RemoteGroupMembers.CSV
 
 .Example - option 2
  Ref48Step1GetRemoteGroupMembers.ps1 -ComputerName (Get-Content c:\Scripts\DesktopComputers.txt)
 
 .Example - option 3
  Ref48Step1GetRemoteGroupMembers.ps1 -ComputerName Desktop01, Desktop02
#>
#Set-ExecutionPolicy remotesigned -Force
#requires -Modules ActiveDirectory
#requires -version 4.0
#requires -RunAsAdministrator
function Ref48Step1GetRemoteGroupMembers {
[CmdletBinding()]

Param(
 [Parameter( ValueFromPipeline=$true,
 ValueFromPipelineByPropertyName=$true
 )]
 [string[]] $ComputerName,
  [string] $RemoteGroupName = 'Administrators',
  [string] $OutputDir = "c:\Scripts"
)
 
Begin {
 if(!($Computername)) {
  Get-Content c:\scripts\destopComputers.csv
  }
 
 else {
 $Computername = $env:COMPUTERNAME
 }
 
 $OutputFile = Join-Path $OutputDir "RemoteGroupMembers.csv"
 Write-Verbose "Script will write the output to $OutputFile folder"
 Add-Content -Path $OutPutFile -Value "ComputerName, RemoteGroupName, Status, MemberType, MemberDomain, MemberName"
}
 
Process {
 ForEach($Computer in $ComputerName) {
     Write-host "Working on $Computer"
     If(!(Test-Connection -ComputerName $Computer -Count 1 -Quiet)) {
     Write-Verbose "$Computer is offline. Proceeding with next computer"
     Add-Content -Path $OutputFile -Value "$Computer,$RemoteGroupName,Offline"
     Continue
     } else 
        {
         Write-Verbose "Working on $computer"
         try {
             $group = [ADSI]"WinNT://$Computer/$RemoteGroupName"
             $members = @($group.Invoke("Members"))
             Write-Verbose "Successfully queries the members of $computer"
             if(!$members) {
                 Add-Content -Path $OutputFile -Value "$Computer,$RemoteGroupName,NoMembersFound"
                 Write-Verbose "No members found in the group"
                 continue
                 }
            }
         catch {
             Write-Verbose "Failed to query the members of $computer"
             Add-Content -Path $OutputFile -Value "$Computer,,FailedToQuery"
             Continue
             }
         foreach($member in $members) {
         try {
             $MemberName = $member.GetType().Invokemember("Name","GetProperty",$null,$member,$null)
             $MemberType = $member.GetType().Invokemember("Class","GetProperty",$null,$member,$null)
             $MemberPath = $member.GetType().Invokemember("ADSPath","GetProperty",$null,$member,$null)
             $MemberDomain = $null
             if($MemberPath -match "^Winnt\:\/\/(?<domainName>\S+)\/(?<CompName>\S+)\/") {
             if($MemberType -eq "User") {
             $MemberType = "RemoteUser"
             } elseif($MemberType -eq "Group"){
             $MemberType = "RemoteGroup"
             }
             $MemberDomain = $matches["CompName"]
 
             } elseif($MemberPath -match "^WinNT\:\/\/(?<domainname>\S+)/") {
             if($MemberType -eq "User") {
                $MemberType = "DomainUser"
                } 
                elseif($MemberType -eq "Group"){
                    $MemberType = "DomainGroup"
                    }
             $MemberDomain = $matches["domainname"]
 
             } 
             else {
                 $MemberType = "Unknown"
                 $MemberDomain = "Unknown"
                 }
            Add-Content -Path $OutPutFile -Value "$Computer, $RemoteGroupName, SUCCESS, $MemberType, $MemberDomain, $MemberName"
             }
          catch {
            Write-Verbose "failed to query details of a member. Details $_"
            Add-Content -Path $OutputFile -Value "$Computer,,FailedQueryMember"
            }
          }
         }
      }
     }
End {} 
}

Select allOpen in new window