How do you get the default binding mode of a dependency property?

binding-mode, c#, data-binding, dependency-properties, wpf

Solution

Use `DependencyProperty.GetMetadata` on the `DependencyObject`. This will give you a `PropertyMetadata` value that will usually be an instance of `FrameworkPropertyMetadata`. Cast to that type if possible and check the value of `BindsTwoWayByDefault`.

For example:

var metadata = property.GetMetadata(target) as FrameworkPropertyMetadata;
if (metadata != null)
{
    var isTwoWay = metadata.BindsTwoWayByDefault;
}

Problem

I want to programmatically find out what the default binding mode of a property will be. For example, if I check it against `TextBox.TextProperty` it should be `BindingMode.TwoWay`, but if it is `ItemsControl.ItemsSourceProperty` it should be `BindingMode.OneWay`. I implemented a custom MarkupExtension and have gotten this far in my code so far: ``` public override object ProvideValue(IServiceProvider provider) { var service = provider.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget; if (service != null) { var target = service.TargetObject as DependencyObject; var property = service.TargetProperty as DependencyProperty; // Not sure what to do with the target and propery here... } } ```

Original source