DesktopCheckBox.ValueChanged
From Xojo Documentation
Event
The CheckBox has been clicked or the value has been changed programmatically. A right-click does not trigger the ValueChanged event.
Notes
Neither changing the VisualState property to indeterminate nor setting it to the value that matches the current Value property will fire the ValueChanged event.
Sample Code
If the CheckBox value has been changed, either programmatically or by the user, then you may want to also cause another action to occur. In this event, you can take the action you need. This example could be used to update an App preference value based on the CheckBox setting:
App.UseLargeFont = Me.Value
This code makes a TextArea read-only based on a CheckBox setting:
TextArea1.ReadOnly = Me.Value