Bind TextBox on Enter-key press

You can make yourself a pure XAML approach by creating an attached behaviour.

Something like this:

public static class InputBindingsManager{    public static readonly DependencyProperty UpdatePropertySourceWhenEnterPressedProperty = DependencyProperty.RegisterAttached(            "UpdatePropertySourceWhenEnterPressed", typeof(DependencyProperty), typeof(InputBindingsManager), new PropertyMetadata(null, OnUpdatePropertySourceWhenEnterPressedPropertyChanged));    static InputBindingsManager()    {    }    public static void SetUpdatePropertySourceWhenEnterPressed(DependencyObject dp, DependencyProperty value)    {        dp.SetValue(UpdatePropertySourceWhenEnterPressedProperty, value);    }    public static DependencyProperty GetUpdatePropertySourceWhenEnterPressed(DependencyObject dp)    {        return (DependencyProperty)dp.GetValue(UpdatePropertySourceWhenEnterPressedProperty);    }    private static void OnUpdatePropertySourceWhenEnterPressedPropertyChanged(DependencyObject dp, DependencyPropertyChangedEventArgs e)    {        UIElement element = dp as UIElement;        if (element == null)        {            return;        }        if (e.OldValue != null)        {            element.PreviewKeyDown -= HandlePreviewKeyDown;        }        if (e.NewValue != null)        {            element.PreviewKeyDown += new KeyEventHandler(HandlePreviewKeyDown);        }    }    static void HandlePreviewKeyDown(object sender, KeyEventArgs e)    {        if (e.Key == Key.Enter)        {            DoUpdateSource(e.Source);        }    }    static void DoUpdateSource(object source)    {        DependencyProperty property =            GetUpdatePropertySourceWhenEnterPressed(source as DependencyObject);        if (property == null)        {            return;        }        UIElement elt = source as UIElement;        if (elt == null)        {            return;        }        BindingExpression binding = BindingOperations.GetBindingExpression(elt, property);        if (binding != null)        {            binding.UpdateSource();        }    }}

Then in your XAML you set the InputBindingsManager.UpdatePropertySourceWhenEnterPressedProperty property to the one you want updating when the Enter key is pressed. Like this

<TextBox Name="itemNameTextBox"         Text="{Binding Path=ItemName, UpdateSourceTrigger=PropertyChanged}"         b:InputBindingsManager.UpdatePropertySourceWhenEnterPressed="TextBox.Text"/>

(You just need to make sure to include an xmlns clr-namespace reference for "b" in the root element of your XAML file pointing to which ever namespace you put the InputBindingsManager in).

This is how I solved this problem. I created a special event handler that went into the code behind:

private void TextBox_KeyEnterUpdate(object sender, KeyEventArgs e){    if (e.Key == Key.Enter)    {        TextBox tBox = (TextBox)sender;        DependencyProperty prop = TextBox.TextProperty;        BindingExpression binding = BindingOperations.GetBindingExpression(tBox, prop);        if (binding != null) { binding.UpdateSource(); }    }}

Then I just added this as a KeyUp event handler in the XAML:

<TextBox Text="{Binding TextValue1}" KeyUp="TextBox_KeyEnterUpdate" /><TextBox Text="{Binding TextValue2}" KeyUp="TextBox_KeyEnterUpdate" />

The event handler uses its sender reference to cause it's own binding to get updated. Since the event handler is self-contained then it should work in a complex DataTemplate. This one event handler can now be added to all the textboxes that need this feature.

I don't believe that there's any "pure XAML" way to do what you're describing. You can set up a binding so that it updates whenever the text in a TextBox changes (rather than when the TextBox loses focus) by setting the UpdateSourceTrigger property, like this:

<TextBox Name="itemNameTextBox"    Text="{Binding Path=ItemName, UpdateSourceTrigger=PropertyChanged}" />

If you set UpdateSourceTrigger to "Explicit" and then handled the TextBox's PreviewKeyDown event (looking for the Enter key) then you could achieve what you want, but it would require code-behind. Perhaps some sort of attached property (similar to my EnterKeyTraversal property) woudld work for you.