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#DELPHI READ EXCEL FILE CODE#
#DELPHI READ EXCEL FILE DOWNLOAD#

Calling particular form of SetFile results in the call of corresponding TStreamReader constructor when TnvvCSVFileReader instantiates TStreamReader internally to actually read the file. Those methods correspond to three overloaded constructors of TStreamReader with the same sets of parameters.

Instead of read-write property FileName, TnvvCSVFileReader uses three overloaded methods to specify source file.

Using TnvvCSVFileReader ClassĬonstructor Create( ABufferReadFromStreamCapacityInChars: Integer = 512 ) override Within each record, iterate through the field values. Simply create an instance of corresponding class, specify the source of CSV data, modify some properties if necessary, call Open, and iterate through records calling Next. Also, parser uses minimum conditional logic.

Reader supposedly is fast since it reads each character directly from TTextReader and analyzes character just once, i.e., reader does one-pass parsing.

Performance related notes are in below "History" section. Version 2.0 update: Version 2.0 does use buffering in order to significantly improve performance. If any buffering is happening, then standard Delphi classes like TStreamReader and TStringReader are responsible for that. It uses memory just enough to store field names and field values of the current record. As an option, the reader can be instructed to simply ignore the special characters. That requirement does not affect line delimiters and field separator and/or quote character if they are from this range.

Characters with codes below 0x20 (and above 0x7E in ASCII case) are considered to be “Special characters” and by default must not appear in the file.

Unicode range of the character codes is assumed by default but can be limited to ASCII only by setting corresponding property to true.

It is assumed that quote character is also used as an escape character.

Quote character by default is double quotes (0x22) but virtually any (Unicode) character can be used.

By default, it is assumed that field may or may not be enclosed in quotes but reader can be instructed not to use field quoting.

Field quoting allows multi-line field values and presence of quote and field separator characters within the field.

Field separator by default is comma (0x2C) but virtually any (Unicode) character can be used, for example, TAB, etc.Number of fields is auto-detected (by default) on the base of the first record or must be set explicitly if auto-detection is off.Empty lines can be ignored (by default, they are not ignored).Presence of header in the very first record of file is controlled by boolean property HeaderPresent.This situation can nonetheless be handled by setting property IgnoreEmptyLines to true. Consequently, the pair will result in an empty line.

Supports three kinds of line delimiters:, and, all of which can be present in the same CSV file simultaneously.

#DELPHI READ EXCEL FILE CODE#

They introduce additional “CSV source” related properties and override the abstract method that returns instance of specific TTextReader descendant:Ĭopy Code function CreateDataSourceReader: TTextReader virtual abstract Ĭlasses for other CSV data sources can be created in a similar way. TnvvCSVFileReader and TnvvCSVStringReader accept file and string as data sources respectively. They are very simple to use and have properties that allow handling number of existing variations of CSV and “CSV-like” formats.Ĭlasses are derived from abstract TnvvCSVReader class that does not specify data source and instead works with instance of TTextReader class. TnvvCSVFileReader and TnvvCSVStringReader are light weighted and fast classes that resemble unidirectional data set. Performance related notes are in "History" section below. Differences are explained in the section "Notable difference between Delphi and C# CSV Reader classes" below. Version 2.0 update: Version 2.0 significantly improves performance and adds encoding control to TnvvCSVFileReader, which resulted in slight modification of public interfaces of base TnvvCSVReader (minor change) and derived TnvvCSVFileReader (more significant change) classes comparing to version 1.0. Below, I will outline the CSV Reader features and will also provide the information related to Delphi code use. It is recommended to read that article first since I am not going to repeat everything here even though there are some minor differences like variable types, etc., but the relation between Delphi and C# specifics is obvious. All said in that article is also true in this case.

#DELPHI READ EXCEL FILE DOWNLOAD#

Download source code v2.0 for Delphi 2009 and later versions - 17.7 KBĬlasses I present here are functionally identical to classes described in the article C# CSV File and String Reader Classes and have the same set of public methods and properties that are explained there in detail.