Public/Add-WPFComboBoxItem.ps1

function Add-WPFComboBoxItem
{
<#
    .SYNOPSIS
        Function to add items from a ComboBox
     
    .DESCRIPTION
        Function to add items from a ComboBox
     
        System.windows.controls.combobox
        https://msdn.microsoft.com/en-us/library/system.windows.controls.combobox(v=vs.110).aspx
     
    .PARAMETER ComboBox
        Specifies the ComboBox control
     
    .PARAMETER Item
        Specifies the item to add
     
    .EXAMPLE
        Add-WPFComboBoxItem -ComboBox $Combobox1 -item (Get-Service).ServiceName
         
    .NOTES
        Francois-Xavier Cat
        lazywinadmin.com
        @lazywinadm
        github.com/lazywinadmin
#>

    Param (
        [ValidateNotNull()]
        [Parameter(Mandatory = $true)]
        [System.Windows.Controls.ComboBox]
        $ComboBox,
        
        [ValidateNotNull()]
        [Parameter(Mandatory = $true)]
        $Item
    )
    BEGIN
    {
        Add-Type –assemblyName PresentationFramework
        Add-Type –assemblyName PresentationCore
        Add-Type –assemblyName WindowsBase
    }
    PROCESS
    {
        
        # Add Items
        FOREACH ($i in $Item)
        {
            #$ComboBox.Items.Add($i)
            $ComboBox.Items.Add($i) | Out-Null
        }
    }
}