How to output results of a function to a ListView form

Trying to figure out how I can output the results of a function to show in a listview in my winforms GUI?
I have the following setup to create a listview and want to know what I need to add to get a function I will be creating to output to the listview window. I am a bit new to this so I am not really sure where to start.

Add-Type -assembly System.Windows.Forms
$main_form = New-Object System.Windows.Forms.Form
$main_form.ClientSize = '600,400'

$List = New-Object System.Windows.Forms.ListView
$List.Location = New-Object System.Drawing.Point(20,175)
$List.Width = 200
$List.Height = 200

$main_form.Controls.Add($List)
$main_form.ShowDialog()

I just helped somebody with something similar on Reddit yesterday. Perhaps this can help get you started.
https://www.reddit.com/r/PowerShell/comments/hyyaj9/treeviewdirectory_tree_help_stuck/

function Show-DirectoryTree {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true, Position = 0)]
        [string]$RootFolder
    )

    # recursive helper function to add folder nodes to the treeview
    function Add-Node {
        param (
            [System.Windows.Forms.TreeNode]$parentNode, 
            [System.IO.DirectoryInfo]$Folder
        )
        Write-Verbose "Adding node $($Folder.Name)"
        $subnode      = New-Object System.Windows.Forms.TreeNode
        $subnode.Text = $Folder.Name
        [void]$parentNode.Nodes.Add($subnode)

        Get-ChildItem -Path $Folder.FullName -Directory | ForEach-Object {
            Add-Node $subnode $_
        }
        Add-Files $subnode $folder
    }

    function Add-Files {
        param (
            [System.Windows.Forms.TreeNode]$parentNode, 
            [System.IO.DirectoryInfo]$Folder
        )
        Get-childitem -path $Folder.FullName -file | ForEach-Object {
            $subnode      = New-Object System.Windows.Forms.TreeNode
            $subnode.Text = $_.name
            [void]$parentNode.Nodes.Add($subnode)
        }
    }
    
    Add-Type -AssemblyName System.Windows.Forms
    Add-Type -AssemblyName System.Drawing

    $Form = New-Object System.Windows.Forms.Form
    $Form.Text = "Files and Folders"
    $Form.Size = New-Object System.Drawing.Size(390, 420)

    $TreeView = New-Object System.Windows.Forms.TreeView
    $TreeView.Location = New-Object System.Drawing.Point(48, 12)
    $TreeView.Size = New-Object System.Drawing.Size(280, 322)
    $Form.Controls.Add($TreeView)

    $rootnode = New-Object System.Windows.Forms.TreeNode
    # get the name of the rootfolder to use for the root node
    $rootnode.Text = [System.IO.Path]::GetFileName($RootFolder.TrimEnd('\'))  #'# or use: (Get-Item -Path $RootFolder).Name
    $rootnode.Name = "Root"

    [void]$TreeView.Nodes.Add($rootnode)
    # expand just the root node
    $rootNode.Expand()

    # get all subdirectories inside the root folder and 
    # call the recursive function on each of them
    Get-ChildItem -Path $RootFolder -Directory | ForEach-Object {
        Add-Node $rootnode $_
    }
    Add-Files $rootnode $RootFolder

    $accept = New-Object System.Windows.Forms.Button
    $accept.Text = "OK"
    $accept.Location = New-Object System.Drawing.Point(230, 345)

    $cancel = New-Object System.Windows.Forms.Button
    $cancel.Text = "Cancel"
    $cancel.Location = New-Object System.Drawing.Point(70, 345)

    $accept.Add_Click({$script:selected = "$rootfolder$($treeview.SelectedNode.FullPath)";$form.Close()})
    $cancel.Add_Click({$form.Close()})

    $form.controls.AddRange(@($accept,$cancel))

    $Form.Add_Shown({$Form.Activate()})
    [void]$Form.ShowDialog()

    $script:selected
    # remove the form when done with it
    $Form.Dispose()
}

# call the function to show the directory tree 
# take off the -Verbose switch if you do not want console output
Show-DirectoryTree -RootFolder 'C:\Temp'

Not sure I really follow what is happening in your code sadly. Not sure what is actually putting the results of the function into the forms element as text.

I actually thinking for my purpose a multi-line textbox is better to use that listview now. My function is just checking multiple servers and reporting back if a service is running or stopped so I won’t need to interact with the data in the box.

I read it wrong anyways, my example is for a treeview. Here is a snippet from another script that demonstrates listview

Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()

$Form                            = New-Object system.Windows.Forms.Form
$Form.ClientSize                 = '519,594'
$Form.text                       = "Some fancy title"
$Form.icon                       #= "c:\path\to\fancyicon.ico"

$namecolumn = New-Object System.Windows.Forms.ColumnHeader
$namecolumn.Name = "name"
$namecolumn.DisplayIndex = 1
$namecolumn.Text = "Name"
$namecolumn.Width = 175

$usercolumn = New-Object System.Windows.Forms.ColumnHeader
$usercolumn.Name = "samaccountname"
$usercolumn.DisplayIndex = 2
$usercolumn.Text = "Login Name"
$usercolumn.Width = 155

$statuscolumn = New-Object System.Windows.Forms.ColumnHeader
$statuscolumn.Name = "status"
$statuscolumn.DisplayIndex = 3
$statuscolumn.Text = "Status"
$statuscolumn.Width = 75

$listView = New-Object System.Windows.Forms.ListView
$listView.View = 'Details'
$listView.Size = New-Object System.Drawing.Size(426,376)
$listView.Location = New-Object System.Drawing.Point(20,62)
$listView.Font = "$($Listview.Font.FontFamily),12"
$null = $listView.Columns.AddRange(@($namecolumn,$usercolumn,$statuscolumn))

$form.controls.Add($listView)

$null = Get-Aduser -filter * | 
            select name,samaccountname,enabled |
                Sort-Object -Property samaccountname |
                    Out-GridView -Title "Ken, please pick some users" -PassThru | 
                        foreach {
                            $itemname = New-Object System.Windows.Forms.ListViewItem($_.name)
                            $itemname.SubItems.Add($_.samaccountname)
                            if ($_.enabled -eq $true) {
                                $itemname.SubItems.Add("Enabled")  
                            }else{
                                $itemname.SubItems.Add("Disabled")  
                            }
                            $listView.Items.Add($itemname)
                        }

$form.ShowDialog()

Still a bit confused…

I don’t see a function in the example so not sure entirely how its showing what a function would output to the console and putting it into the form element. I decided to use a textbox instead of a listview.

My goal is take my function that is checking servers to see if specific services are running and outputting that data to the textbox when a button is clicked.