protected override void OnPageOpened()
Called when the SmartPage is displayed for the first time.
SmartPage calls OnPageOpened() from the FrameworkElement.Loaded event.
Ventura will remove a SmartPage from the visual tree, and re-attach a SmartPage to the visual tree, when:
a) selecting a different Tab;
b) overlaying a modal page with SmartPage.OpenModal().
This will result in SmartPage.Loaded and SmartPage.Unloaded event to be fired again and again. However, OnPageOpened() is only called when the SmartPage is displayed for the first time.
protected override void OnPageClosed()
Called when the page is closed.