Using a existing sting to preform a function on a list of computers

Question

I know this test works fine
$computers
= "S2008C1","S2008C1","S2008C3"
Get-WmiObject
-Class win32_bios
-cn $computers
|
Format-table
__Server,
Manufacturer,
Version -AutoSize
It produces
__SERVER Manufacturer             Version        
S2008C1  American Megatrends Inc. VRTUAL - 5001223
S2008C1  American Megatrends Inc. VRTUAL - 5001223
S2008C3  American Megatrends Inc. VRTUAL - 5001223
however when I have the user input the computer names (see screen shot below) it does not pull any of the info for the computers in the list.   I know the variable has the correct list as it print the list to the console but it will not perform any
functions.  I have tried this using several methods. I am just trying to relay I have done my best to do my homework.
The part that is not working is the last 3 lines below.  By not working i meant it does nothing.
Thanks 
function Read-MultiLineInputBoxDialog([string]$Message, [string]$WindowTitle, [string]$DefaultText)
<#
.SYNOPSIS
Prompts the user with a multi-line input box and returns the text they enter, or null if they cancelled the prompt.
.DESCRIPTION
Prompts the user with a multi-line input box and returns the text they enter, or null if they cancelled the prompt.
.PARAMETER Message
The message to display to the user explaining what text we are asking them to enter.
.PARAMETER WindowTitle
The text to display on the prompt window's title.
.PARAMETER DefaultText
The default text to show in the input box.
.EXAMPLE
$userText = Read-MultiLineInputDialog "Input some text please:" "Get User's Input"
Shows how to create a simple prompt to get mutli-line input from a user.
.EXAMPLE
# Setup the default multi-line address to fill the input box with.
$defaultAddress = @'
John Doe
123 St.
Some Town, SK, Canada
A1B 2C3
$address = Read-MultiLineInputDialog "Please enter your full address, including name, street, city, and postal code:" "Get User's Address" $defaultAddress
if ($address -eq $null)
Write-Error "You pressed the Cancel button on the multi-line input box."
Prompts the user for their address and stores it in a variable, pre-filling the input box with a default multi-line address.
If the user pressed the Cancel button an error is written to the console.
.EXAMPLE
$inputText = Read-MultiLineInputDialog -Message "If you have a really long message you can break it apart`nover two lines with the powershell newline character:" -WindowTitle "Window Title" -DefaultText "Default text for the input box."
Shows how to break the second parameter (Message) up onto two lines using the powershell newline character (`n).
If you break the message up into more than two lines the extra lines will be hidden behind or show ontop of the TextBox.
.NOTES
Name: Show-MultiLineInputDialog
Author: Daniel Schroeder (originally based on the code shown at http://technet.microsoft.com/en-us/library/ff730941.aspx)
Version: 1.0
#>
Add-Type -AssemblyName System.Drawing
Add-Type -AssemblyName System.Windows.Forms
# Create the Label.
$label = New-Object System.Windows.Forms.Label
$label.Location = New-Object System.Drawing.Size(10,10)
$label.Size = New-Object System.Drawing.Size(280,20)
$label.AutoSize = $true
$label.Text = $Message
# Create the TextBox used to capture the user's text.
$textBox = New-Object System.Windows.Forms.TextBox
$textBox.Location = New-Object System.Drawing.Size(10,40)
$textBox.Size = New-Object System.Drawing.Size(575,200)
$textBox.AcceptsReturn = $true
$textBox.AcceptsTab = $false
$textBox.Multiline = $true
$textBox.ScrollBars = 'Both'
$textBox.Text = $DefaultText
# Create the OK button.
$okButton = New-Object System.Windows.Forms.Button
$okButton.Location = New-Object System.Drawing.Size(415,250)
$okButton.Size = New-Object System.Drawing.Size(75,25)
$okButton.Text = "OK"
$okButton.Add_Click({ $form.Tag = $textBox.Text; $form.Close() })
# Create the Cancel button.
$cancelButton = New-Object System.Windows.Forms.Button
$cancelButton.Location = New-Object System.Drawing.Size(510,250)
$cancelButton.Size = New-Object System.Drawing.Size(75,25)
$cancelButton.Text = "Cancel"
$cancelButton.Add_Click({ $form.Tag = $null; $form.Close() })
# Create the form.
$form = New-Object System.Windows.Forms.Form
$form.Text = $WindowTitle
$form.Size = New-Object System.Drawing.Size(610,320)
$form.FormBorderStyle = 'FixedSingle'
$form.StartPosition = "CenterScreen"
$form.AutoSizeMode = 'GrowAndShrink'
$form.Topmost = $True
$form.AcceptButton = $okButton
$form.CancelButton = $cancelButton
$form.ShowInTaskbar = $true
# Add all of the controls to the form.
$form.Controls.Add($label)
$form.Controls.Add($textBox)
$form.Controls.Add($okButton)
$form.Controls.Add($cancelButton)
# Initialize and show the form.
$form.Add_Shown({$form.Activate()})
$form.ShowDialog() > $null # Trash the text of the button that was clicked.
# Return the text that the user entered.
return $form.Tag
Clear-Host
$pcnamelist = Read-MultiLineInputBoxDialog -Message "PC NAME LIST" -WindowTitle "Multi Line Example" -DefaultText "Enter PC name(s) each PC must be on its own line and no spaces"
if ($pcnamelist -eq $null) { Write-Host "You clicked Cancel" }
else {
# $pcnamelist = $pcnamelist -replace '(^\s+|\s+$)','' -replace '\s+',' '
Write-Host "You entered the following text:
$pcnamelist"
$pcnamelist
Get-WmiObject -Class win32_bios -cn $pcnamelist -EA silentlyContinue |
Format-table __Server, Manufacturer, Version –AutoSize
R White

Answer 1

I entered a couple of lines with . and . for hosts, $PCnamelist is coming back as a string of length 6
To see what is actually returned check out the ascii codes.
PS C:\Users\User> For ($I=0;$I -LT $PCNameLIst.Length;$I++){$C=$PCNameList.Chars($I);$C -as [int]}
46
13
10
46
13
10
There is cr-lf for each line, problem is Get-WMIObject is expecting an array, ie, String[]
The extra cr-lf at the end needs to be stripped off if present otherwise an extra empty element is present
PS C:\Users\User> $PCNames = $PCNameList.Split("`r`n")
$PCNames.Count
3
Something like this at the end of the function is needed
$PCNameList
# Check for extra CR-LF and remove it
While ($PCNameList.Chars($PCNameList.Length-1) -eq "`n")
{$PCNameList=$PCNameList.Substring(0,$PCNameList.Length-2)}
# Split string on CR-LF
$PCNames = $PCNameList.Split("`r`n")
# Return PCNames
Return $PCNames
First thanks for this great replay.   I have been trying to alter small sections of it to get a better idea of what it is doing.      
I have had no luck getting it to work.   It still acts like there is no list of PC's no mater how i alter it or wither i use $PCName or $PCNamelist
Below is the section i have focused on.  Again thanks for any help.  
### https://social.technet.microsoft.com/Forums/en-US/30078df4-aeca-45f6-bd7f-7106fd0d264c/using-a-existing-sting-to-preform-a-function-on-a-list-of-computers?forum=winserverpowershell
# The below code will show the ascii code of what is stored in the pcnamelist variable
For ($I=0;$I -LT $PCNameLIst.Length;$I++)
{$C=$PCNameList.Chars($I);$C -as [int]}
# The above code will show the ascii code of what is stored in the pcnamelist variable
# The below code will format the user input
$PCNameList
# Check for extra CR-LF and remove it
While ($PCNameList.Chars($PCNameList.Length-1) -eq "`n")
{$PCNameList=$PCNameList.Substring(0,$PCNameList.Length-2)}
# Split string on CR-LF
$PCNames = $PCNameList.Split("`r`n")
Return PCNames
Return $PCNames
Write-Host below is '$PCNames'
$PCNames
Write-Host below is '$PCNamelist'
$PCNamelist
Get-WmiObject -Class win32_bios -cn $PCNames -EA silentlyContinue |
Format-table __Server, Manufacturer, Version –AutoSize
R White