Silent exception when binding PivotItem header - windows-phone-7

Question

I've noticed a strange exception in my Windows Phone 7.1 application that really made me crazy.
These are the facts...
I start defining a simple Pivot item with two simple PivotItem inside:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<controls:Pivot>
<controls:PivotItem x:Name="PivotItem1"
Header="Test1" />
<controls:PivotItem x:Name="PivotItem2"
Header="{Binding Path=Text2, Mode=OneWay}" />
</controls:Pivot>
<Button Content="Test" Click="Button_Click" />
</Grid>
And this is my code-behind...
EDIT: As Gambit suggested me, I will show you more code.
In the real situation, I DO HAVE A MVVM, but in this case I simplified the situation to let you reproduce the problem in an easy way...
For this test the next is my View:
public partial class MainPage : PhoneApplicationPage, INotifyPropertyChanged
{
private string _text2 = "<Missing>";
public string Text2
{
get
{
return _text2;
}
private set
{
_text2 = value;
NotifyPropertyChanged("Text2");
}
}
public MainPage()
{
InitializeComponent();
}
private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
this.DataContext = this;
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
private void Button_Click(object sender, RoutedEventArgs e)
{
this.Text2 = "Second page";
}
}
So, it's not just the parameter initialization of a NULL value: you will see the exception.
Obviously, you are asking me for the controls namespace declaration. This is:
xmlns:controls="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls"
This refers to the assembly Microsoft.Phone.Controls.dll, version 2.0.50727.
My problem is related to the binding (as I discovered investigating the problem):
Header="{Binding Path=Text2, Mode=OneWay}"
If you do not use bindings linked to the Header property of the PivotItem, everything works well, otherwise...the app will throw an exception, completely silent, and it won't show up in any case (you can see the exception only in the Output Window):
A first chance exception of type 'System.Exception' occurred in System.Windows.dll
If you assign the Header property manually, no exceptions will be thrown.
I want to completely remove this exceptions, because I have a lot of bindings to the Header property, I don't want to break my MVVM...and it's also very annoying!
I really hate to see unmanaged exceptions...
Does anyone know about this problem?
Any solution/workaround?
Any help will be very appreciated...thank you!

Answer 1

Based on the code provided, I would suspect that the issue is the DataContext is not being set. In your example, the DataContext is set in the PhoneApplicationPage_Loaded event. However, it doesn't appear that you are registering for this event anywhere. In the constructor of MainPage, add a line like:
this.Loaded += new RoutedEventHandler(PhoneApplicationPage_Loaded);