//tries to get a CommandBehaviorBinding from the element. Creates a new instance if there is not one attached
private static CommandBehaviorBinding FetchOrCreateBinding(DependencyObject d)
{
CommandBehaviorBinding binding = CommandBehavior.GetBehavior(d);
if (binding == null)
{
binding = new CommandBehaviorBinding();
CommandBehavior.SetBehavior(d, binding);
}
return(binding);
}
/// <summary>
/// Handles changes to the Event property.
/// </summary>
private static void OnEventChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CommandBehaviorBinding binding = FetchOrCreateBinding(d);
//check if the Event is set. If yes we need to rebind the Command to the new event and unregister the old one
if (binding.Event is not null && binding.Owner is not null)
{
binding.Dispose();
}
//bind the new event to the command
binding.BindEvent(d, e.NewValue.ToString());
}
/// <summary>
/// Handles changes to the Action property.
/// </summary>
private static void OnActionChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CommandBehaviorBinding binding = FetchOrCreateBinding(d);
binding.Action = (Action <object>)e.NewValue;
}
/// <summary>
/// Handles changes to the Command property.
/// </summary>
private static void OnCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CommandBehaviorBinding binding = FetchOrCreateBinding(d);
binding.Command = (ICommand)e.NewValue;
}
/// <summary>
/// Sets the Behavior property.
/// </summary>
private static void SetBehavior(DependencyObject d, CommandBehaviorBinding value)
{
d.SetValue(BehaviorProperty, value);
}
