/// <summary>
/// Gets the data property binding from a dependency object or its parent.
/// </summary>
/// <param name="obj">Dependency object.</param>
/// <returns>Data property binding or null if not found.</returns>
private static DataPropertyBinding GetBinding(DependencyObject obj)
{
if (obj == null)
{
return(null);
}
DataPropertyBinding b = obj.GetValue(Property.BindingProperty) as DataPropertyBinding;
return(b);
}
/// <summary>
/// A handler of the data context change event on a text block that has a value format dependency property set,
/// which updates the text of the text block to be formatted according to the specified value format.
/// </summary>
/// <param name="sender">Event sender, which should be a text block.</param>
/// <param name="e">Event arguments.</param>
private static void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (!(sender is TextBlock tb))
{
return;
}
DataPropertyBinding binding = GetBinding(tb);
if (binding != null && binding.BoundProperty != null)
{
tb.Text = binding.BoundProperty.ValueToString(tb.DataContext, GetValueFormat(tb));
}
}
/// <summary>
/// A callback that is triggered when a data property name or a child object path
/// are set on a framework element. It sets up a new data property binding on the element.
/// </summary>
/// <param name="d">The framework element.</param>
/// <param name="e">Event arguments.</param>
public static void SetupBinding(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
// calling a static method IsBindable ensures that
// the static constructor is called and all WPF bindings get registered
if (DataPropertyBinding.IsBindable(d))
{
BaseBinding oldBinding = d.GetValue(BindingProperty) as BaseBinding;
if (oldBinding != null)
{
oldBinding.Dispose();
}
d.SetValue(BindingProperty, BaseBinding.Create(d));
}
}
