Responsive PowerShell WPF Form Introduction #1

Hooooly jebus chwist! This took a LONG time for me to get my head around and an even longer time to implement and get working (still breaking it every minute!). I used this website and this website to help me learn the basics.

Today, I’m going to show you how to create a responsive WPF from using PowerShell. This utilises runspaces and a synchronised hashta… never mind the technical stuff!

This is the code that I used:

#CREATE HASHTABLE AND RUNSPACE FOR GUI
$syncHash = [hashtable]::Synchronized(@{})
$newRunspace =[runspacefactory]::CreateRunspace()
$newRunspace.ApartmentState = "STA"
$newRunspace.ThreadOptions = "ReuseThread"         
$newRunspace.Open()
$newRunspace.SessionStateProxy.SetVariable("syncHash",$syncHash)      
#BUILD GUI AND ADD TO RUNSPACE CODE
$psCmd = [PowerShell]::Create().AddScript({   
    $xaml = @"
    <Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    Name="Window" Height="400" Width="600">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>

        <Button Name="Button" Content="Press" Height="200" Width="580" Grid.Row="0" Grid.Column="0" />
        <TextBox Name="Textbox" Height="200" Width="580" Grid.Row="1" Grid.Column="0" />
    </Grid>
</Window>
"@
  
    #INTERPRET AND LOAD THE GUI
    $reader=(New-Object System.Xml.XmlNodeReader $xaml)
    $syncHash.Window=[Windows.Markup.XamlReader]::Load( $reader )

    #EXTRACT THE CONTROLS FROM THE GUI
    $syncHash.TextBox = $syncHash.window.FindName("Textbox")
    $syncHash.Button = $syncHash.Window.FindName("Button")

    #FINALISE AND CLOSE GUI RUNSPACE UPON EXITING
    $syncHash.Window.ShowDialog() | Out-Null
    $syncHash.Error = $Error
    $Runspace.Close()
    $Runspace.Dispose()
    
})
#LOAD RUNSPACE WITH GUI IN
$psCmd.Runspace = $newRunspace
$data = $psCmd.BeginInvoke()

Using this, you can then use the same command prompt used to launch the script to change the form. E.g. to change the text in the textbox we would use:

$syncHash.Window.Dispatcher.Invoke(
    [action]{$syncHash.TextBox.Text = "Updated text here"}
)

In another post, I’ll show you how to update the textbox using a button on the same form. Exciting stuff, right?

Leave a comment if you have any questions or issues. Enjoy!

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