WPF TwoWay not working on X (exit) but works on TAB or clicking elsewhere

Question

I have the following in my XAML:

<TextBox Name="TitleValue" 
         Text="{Binding ElementName=ListValue, Path=SelectedItem.Title, Mode=TwoWay}"

<TextBox Name="DescValue"
         Text="{Binding ElementName=ListValue, 
                        Path=SelectedItem.Description, Mode=TwoWay}"

When I enter a value in either TitleValue or DescValue and Tab or click on a different location in the window, the collection class properties are updated correctly. Then when I click the X to exit the window, the data in the collection class is saved correctly.

However, when I enter a value in either of those fields, then click X to exit the window, the data in the collection class is saved, but the value entered is not saved for that particular field I was editing when I clicked X.

I implemented a lose focus event on the fields and they work, even when the X is clicked. In those events I put the code:

private void Event_DescValue_LoseFocus(object sender, RoutedEventArgs e)
{
    ((Import)ListValue.SelectedItem).Description = ((TextBox)e.OriginalSource).Text;
}

But that didn't work either. the following does not work either:

Imports[ListValue.SelectedIndex].Description = ((TextBox)e.OriginalSource).Text;

How do I get the collection class Imports to update the selected class Import when X is clicked when in a field being edited?

It should work exactly like I had Tabbed off the field being edited or clicking elsewhere in the window.

Answer 1

Modify your binding's UpdateSourceTrigger to PropertyChanged.

Like so:

<TextBox Name="TitleValue" Text="{Binding ElementName=ListValue, 
     Path=SelectedItem.Title, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>