Author Posts

August 8, 2016 at 4:15 pm

The requirement is to display a user control in a tab item. The below is the code I am trying. I am trying to use a WPF User control in PowerShell. Everything is working fine but when I select the tab item then getting the focus error.

I tried to resolve it by own and even tried to seek help from others but unfortunately unable to fix it.

Add-Type -AssemblyName PresentationFramework
[xml]$MainXAML = @"


[xml]$UserControlXAML = @"


$MainReader = New-Object System.Xml.XmlNodeReader $MainXAML
$Window_Main= [Windows.Markup.XamlReader]::Load($MainReader) in 
$UC_Reader = New-Object System.Xml.XmlNodeReader $UserControlXAML
$Window_UC= [Windows.Markup.XamlReader]::Load($UC_Reader)

$MainXAML.SelectNodes("//*[@Name]") | %{ Set-Variable -Name ("WPF_Main_"+$_.Name) -Value $Window_Main.FindName($_.Name) -Scope "Script" }
$UserControlXAML.SelectNodes("//*[@Name]") | %{ Set-Variable -Name ("WPF_UC_"+$_.Name) -Value $Window_UC.FindName($_.Name) -Scope "Script" }
    Write-Host -ForegroundColor Green "I am in the click event."
    $TabItem1 = New-Object System.Windows.Controls.TabItem
    $TabItem1.Header = "Eureka"

Error that I am getting

Hide   Copy Code
Exception calling "ShowDialog" with "0" argument(s): "Must disconnect specified child from current parent Visual before attaching to new parent Visual."
At line:50 char:1
+ $Window_Main.ShowDialog()
+ ~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : ArgumentException

August 8, 2016 at 8:39 pm

Sadly, and I hate to do this, but you might get better results in StackOverflow – more developers there, more playing with WPF. But please, if you do figure it out, a link to the solution will be appreciated by future generations ;).

August 9, 2016 at 1:25 am

Can you try to re-paste your code? I'm not seeing any of the XAML code so I cannot test to see what the issue might be.

August 9, 2016 at 3:21 am

Hi Prox,
every time the xml part is vanishing. Let me try gist. In other hand may I have your email address so that I can post it to you?

  • This reply was modified 2 years ago by  Sagar PS.

August 9, 2016 at 3:02 pm

I have fixed this issue. I am unable to paste the solved code here since xml part is auto wiping. The solution is, we should create all the controls with in a grid control and add only the grid control to the target control 🙂

May 28, 2018 at 12:59 am

Hi Sagar,

Would you please provide an example in plain text? I am running into the same problem using User Control within PowerShell.

As you can see from my example below, I get a namespace error when I try implementing UserControls within PowerShell. Am I wrong, is it possible? Any help is appreciated.

For example:
If I tried implementing a XAML User Control and binding it with PowerShell but it fails with a namespace error. My test project has two XAML files and one PS1 script that can be found in my GitHub.


Project files
1. MainWindow.xaml
2. MyListBoxItem.xaml
3. UsrControl.PS1

PowerShell error:
PS C:\WINDOWS\system32> C:\Temp\UserControl\usrcontrol.ps1
Get-ChildItem : Exception calling "Load" with "1" argument(s): "Cannot create unknown type '{clr-namespace:Test.Controls;assembly=Test.Controls}MyListBoxItem'."
At C:\Temp\UserControl\usrcontrol.ps1:68 char:8
+ $wpf = Get-ChildItem -Path $path -Filter *.xaml -file | Where-Object ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Get-ChildItem], MethodInvocationException
+ FullyQualifiedErrorId : XamlParseException,Microsoft.PowerShell.Commands.GetChildItemCommand