Esempio n. 1
0
        /// <summary>
        /// Writes all rows in <paramref name="this"/> to <paramref name="csvWriter"/>.
        /// </summary>
        /// <remarks>
        /// </remarks>
        /// <param name="this">
        /// The <see cref="DataTable"/>.
        /// </param>
        /// <param name="csvWriter">
        /// The <see cref="CsvWriter"/>.
        /// </param>
        /// <param name="writeHeaderRecord">
        /// If <see langword="true"/>, a header record will also be written, which will be comprised of the column names defined for <paramref name="this"/>.
        /// </param>
        /// <param name="maximumRows">
        /// The maximum number of rows from <paramref name="this"/> that should be written to <paramref name="csvWriter"/>.
        /// </param>
        /// <param name="objectToStringConverter">
        /// Provides a means of converting values in the <see cref="DataRow"/>s to <see cref="String"/>s.
        /// </param>
        /// <returns>
        /// The actual number of rows from <paramref name="this"/> written to <paramref name="csvWriter"/>.
        /// </returns>
        public static int WriteCsv(this DataTable @this, CsvWriter csvWriter, bool writeHeaderRecord, int? maximumRows, Func<object, string> objectToStringConverter)
        {
            @this.AssertNotNull("@this");
            csvWriter.AssertNotNull("csvWriter");
            objectToStringConverter.AssertNotNull("objectToStringConverter");

            var num = 0;

            if (writeHeaderRecord)
            {
                var columnNames = new string[@this.Columns.Count];

                for (var i = 0; i < columnNames.Length; ++i)
                {
                    columnNames[i] = @this.Columns[i].ColumnName;
                }

                csvWriter.WriteRecord(columnNames);
            }

            var maximum = maximumRows.GetValueOrDefault(int.MaxValue);
            var buffer = new DataRecord[16];
            var bufferOffset = 0;

            foreach (DataRow row in @this.Rows)
            {
                var record = new DataRecord();

                for (var i = 0; i < row.ItemArray.Length; ++i)
                {
                    record.Add(objectToStringConverter(row.ItemArray[i]));
                }

                buffer[bufferOffset++] = record;

                if (bufferOffset == buffer.Length)
                {
                    // buffer full
                    csvWriter.WriteRecords(buffer, 0, buffer.Length);
                    bufferOffset = 0;
                }

                if (++num == maximum)
                {
                    break;
                }
            }

            // write any outstanding data in buffer
            csvWriter.WriteRecords(buffer, 0, bufferOffset);

            return num;
        }