Update-WPFJob.ps1

function Update-WPFJob
{
    <#
    .Synopsis
        Updates a running WPF Job by running a PowerShell script
    .Description
        Runs a PowerShell script within a WPF Job and returns the results.
        This enables two way communication with WPF Jobs.
        You can use the $Window variable and Get-ChildControl to talk to 
        individual controls within a UI.
    .Example
        $Job = New-Label "Hello World" -AsJob
        $job | Update-WPFJob { $window.Close() }
    #>
    [CmdletBinding(DefaultParameterSetName='NoParameters')]
    param(
    # The Job to update
    [Parameter(Mandatory=$true,
        ValueFromPipeline=$true)]
    [Management.Automation.Job]
    $Job,
    
    [Parameter(Position=0)]
    [ScriptBlock]
    $Command,
    
    [Parameter(ParameterSetName='IDictionary', Position=1)]
    [Collections.IDictionary]
    $Dictionary,
    
    [Parameter(ParameterSetName='IList', Position=1)]
    [Collections.IList]
    $List
    )
    
    process {
        if ($job.InvokeScriptInJob) {
            switch ($psCmdlet.ParameterSetName) {
                NoParameters {
                    $job.InvokeScriptInJob($Command, $null)
                }
                List {
                    $job.InvokeScriptInJob($command, $List)
                }
                Dictionary {
                    $job.InvokeScriptInJob($Command, $Dictionary)
                }
            }
        }
    }
    
}