System.Data.SqlClient.SqlDataReader.SqlDataReader.GetBytes C# (CSharp) Method

		long GetBytes (int i, long dataIndex, byte[] buffer, int bufferIndex, int length)
		{
			if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
				ValidateState ();
				EnsureDataAvailable ();

				try {
					long len = ((Tds)command.Tds).GetSequentialColumnValue (i, dataIndex, buffer, bufferIndex, length);
					if (len == -1)
						throw CreateGetBytesOnInvalidColumnTypeException (i);
					if (len == -2)
#if NET_2_0
						throw new SqlNullValueException ();
#else
						return 0;
#endif
					return len;
				} catch (TdsInternalException ex) {
					command.Connection.Close ();
					throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
				}
			}

			object value = GetValue (i);
			if (!(value is byte [])) {
				SqlDbType type = GetSchemaRowDbType (i);
				switch (type) {
				case SqlDbType.Image:
					if (value is DBNull)
						throw new SqlNullValueException ();
					break;
				case SqlDbType.Text:
#if NET_2_0
					string text = value as string;
					if (text != null)
						value = Encoding.Default.GetBytes (text);
					else
						value = null;
					break;
#else
					throw new InvalidCastException ();
#endif
				case SqlDbType.NText:
#if NET_2_0
					string ntext = value as string;
					if (ntext != null)
						value = Encoding.Unicode.GetBytes (ntext);
					else
						value = null;
					break;
#else
					throw new InvalidCastException ();
#endif
				default:
					throw CreateGetBytesOnInvalidColumnTypeException (i);
				}
			}

			if (buffer == null)
				return ((byte []) value).Length; // Return length of data

			// Copy data into buffer
			int availLen = (int) ( ( (byte []) value).Length - dataIndex);
			if (availLen < length)
				length = availLen;
			if (dataIndex < 0)
				return 0;
			
			Array.Copy ((byte []) value, (int) dataIndex, buffer, bufferIndex, length);
			return length; // return actual read count
		}