System.Data.DataKey.DataKey C# (CSharp) Method

        internal DataKey(DataColumn[] columns, bool copyColumns)
        {
            if (columns == null)
            {
                throw ExceptionBuilder.ArgumentNull(nameof(columns));
            }

            if (columns.Length == 0)
            {
                throw ExceptionBuilder.KeyNoColumns();
            }

            if (columns.Length > maxColumns)
            {
                throw ExceptionBuilder.KeyTooManyColumns(maxColumns);
            }

            for (int i = 0; i < columns.Length; i++)
            {
                if (columns[i] == null)
                {
                    throw ExceptionBuilder.ArgumentNull("column");
                }
            }

            for (int i = 0; i < columns.Length; i++)
            {
                for (int j = 0; j < i; j++)
                {
                    if (columns[i] == columns[j])
                    {
                        throw ExceptionBuilder.KeyDuplicateColumns(columns[i].ColumnName);
                    }
                }
            }

            if (copyColumns)
            {
                // Need to make a copy of all columns
                _columns = new DataColumn[columns.Length];
                for (int i = 0; i < columns.Length; i++)
                {
                    _columns[i] = columns[i];
                }
            }
            else
            {
                // take ownership of the array passed in
                _columns = columns;
            }
            CheckState();
        }