public object GetValue(AttachedProperty property, object instance)
{
AttachedPropertyMetadata metadata;
if (!metadataStore.TryGetMetadata(property.OwnerType, property, out metadata))
{
throw new InvalidOperationException();
}
if (metadata.Inherits)
{
object val;
if (TryGetValueFromParentTree(property, instance, out val))
{
return(val);
}
}
else
{
object val;
var prop = new AttachedPropertyEntry(property, instance);
if (values.TryGetValue(prop, out val))
{
return(val);
}
}
return(metadata.DefaultValue);
}
private bool TryGetValueFromParentTree(AttachedProperty property, object instance, out object val)
{
do
{
var prop = new AttachedPropertyEntry(property, instance);
if (values.TryGetValue(prop, out val))
{
return(true);
}
instance = getParentFunc(instance);
} while (instance != null);
return(false);
}