System.Data.LookupNode.Eval C# (CSharp) Метод

        internal override object Eval(DataRow row, DataRowVersion version)
        {
            if (_column == null || _relation == null)
                throw ExprException.ExpressionUnbound(ToString());

            DataRow parent = row.GetParentRow(_relation, version);
            if (parent == null)
                return DBNull.Value;

            return parent[_column, parent.HasVersion(version) ? version : DataRowVersion.Current];
        }