How to output to clipboard - powershell

Question

I have a GUI listview with 3 columns (FullRowSelect enabled)
With a Copy button, that I want to copy the 3 columns of each row into the clipboard, so that there is a new line for each row.
But what happens is I get the 3 columns of each row joined together in one string.
NB the Write-Host's are just there to help me see what's going on, this is part of a no console GUI app in PowerShell
I've tried piping $output via Out-String | clip and others, but always get the same result of the whole lot being in one line.
I'm sure this is probably something very simple ! my PS skills are just basic !
Please can someone point me in the right direction :)
Function Copy2ClipBoard {
foreach ($line in $OutputlistView.SelectedItems) {
$allitems = ($line.SubItems[0].Text + " , " + $line.SubItems[1].Text + " , " + $line.SubItems[2].Text)
$Output += $allitems
Write-Host $allitems
}
Write-Host ""
Write-Host $Output
[System.Windows.Forms.Clipboard]::SetText($Output)
}

Answer 1

Will only work in PowerShell 5.x, since PowerShell 6 doesn't offer this cmdlet ...
You can use the ´Set-Clipboard` cmdlet.
Function Copy2ClipBoard {
# Clear the clipboard
Set-Clipboard
foreach ($line in $OutputlistView.SelectedItems) {
$allitems = ($line.SubItems[0].Text + " , " + $line.SubItems[1].Text + " , " + $line.SubItems[2].Text)
$Output += $allitems
Set-Clipboard -Value $allitems -Append
Write-Host $allitems
}
Write-Host ""
Write-Host $Output
}
You can check the clipboard via Get-Clipboard.
Hope that helps.

Answer 2

Your problem does not like with clip.
but always get the same result of the whole lot being in one line.
That is because you are just building a progressively longer string and not an array as you seem to think. When you do $Output += $allitems you are just adding the $allitems string to $output with a space in between. Moerwalds solution skirts around this by using the -Append parameter of Set-Clipboard.
In reality you could just deal with your input string in one of a few ways. Simplest would be piping into clip, you could also use something like -join "`r`n"
$OutputlistView.SelectedItems | Foreach-Object{
$_.SubItems[0].Text + " , " + $_.SubItems[1].Text + " , " + $_.SubItems[2].Text
} | clip