VDS: strange behaviour fpr property validation

[daniel_luescher]

Hi everyone,

I want to validate the input of a text box, and I tryed to follow the VDS Tutorial chapter 12.

In File.xaml I defined:

<TextBox x:Name="txtDevProNr" Text="{Binding Prop[devProNr].Value}"...

The property "devProNr" is not a Vault property.

In Default.ps1 I defined:

$Prop["devProNr"].CustomValidation = { DevProNrValidation }

"DevProNrValidation" is the function with the defined validation.

The behaviour is the following: CustomValidation doesn't react to the change in the input of the text box, but reacts in the change of the category (I found no link between the text box and the category).

If the category is changed, CustomValidation checks if the text box is conform to the DevProNrValidation function.

Is there an explanation for this behaviour?

Thanks Daniel

VDS Version: 2026.0.1

[Markus.Koechl · Accepted solution]

 Hi @daniel_luescher : The tutorial consumes default XAML files/properties that use ValidatedBinding instead of Binding.