Silverlight TabControl SelectionChanged

This is a strange behaviour I encountered with the Silverlight TabControl SelectionChanged event.

My XAML is defined as such:

<basics:TabControl x:Name="ReportTabs" SelectionChanged="ReportTabs_SelectionChanged" >

...

</basics:TabControl >

In my cs file, I have defined the corresponding ReportTabs_SelectionChanged function.

private void ReportTabs_SelectionChanged(object sender, SelectionChangedEventArgs e)

{

TabItem item = ReportTabs.SelectedItem as TabItem;

if (item == tabAdvancedRpt)

{

Page1Panel.Visibility = Visibility.Visible;

Page2Panel.Visibility = Visibility.Collapsed;

}

}

This will give me initialisation error when I try to run the Silverlight project.

This is because on the first hit of this SelectionChanged event, the TabControl has not been initialised. As such, there is a need to check if ReportTabs == null.

Why does the SelectionChanged event get hit even when the control is not initialised? Strange...