Display Get-Process with ListView

I'm experimenting with PowerShell and trying to learn more about it. So far I've grasped the basics and am now trying to use it in conjunction PrimalForms to create a GUI. What I want to do is, with the press of a button, neatly display all currently running processes, similarly to the task manager.

I would like it to have three columns, one for the process' name, one for its CPU load and a third for the ID.

$sampleForm = New-Object System.Windows.Forms.Form
$sampleForm.Width = 300
$sampleForm.Height = 300

$listView = New-Object System.Windows.Forms.ListView
$listView.View = 'Details'
$listView.Width = 300
$listView.Height = 300

$listView.Columns.Add('ID')
$listView.Columns.Add('Process name')
$listView.Columns.Add('CPU Load')

Get-Process | %{
    Add-ListViewItem -ListView $listView `
        -Items $_.ID`
        -SubItems $_.ProcessName, $_.CPU
}

$sampleForm.Controls.Add($listView)
[void] $sampleForm.ShowDialog()

So far I've done it less elegantly with the above code, it works by itself but not when I combine it with the code generated by PrimalForms. Together with the code from PrimalForms the ListView output will only output all the processes, but not create the columns. How can I create these columns and properly place everything where it should be? Any help is greatly appreciated!