private PropertyDescriptor GetPropertyDescriptorFromFirstItem(object firstItem) { if (string.IsNullOrEmpty(this.RelationName) || (firstItem == null)) { return(null); } var descriptor = ItemsSourceHelper.GetCustomTypeDescriptor(firstItem, firstItem.GetType()); if (descriptor == null) { return(null); } var properties = descriptor.GetProperties(); if ((properties != null) && (properties.Count > 0)) { return(properties[this.RelationName]); } return(null); }