Delphi 10.3 Rio 中处理 CSV

读取 CSV 文件

我没有合适的 CSV 文件，所以我转换了 Delphi 示例数据库来创建一个 CSV。

第一行是标题。

"NAME","SIZE","WEIGHT","AREA"

"Angel Fish",2,2,"Computer Aquariums"

"Boa",10,8,"South America"

"Critters",30,20,"Screen Savers"

"House Cat",10,5,"New Orleans"

"Ocelot",40,35,"Africa and Asia"

"Parrot",5,5,"South America"

"Tetras",2,2,"Fish Bowls"

program ReadCSV;

{$APPTYPE CONSOLE}

{$R *.res}

uses

  System.Classes, System.SysUtils;

begin

  var Reader := TStreamReader.Create('animals.csv', TEncoding.Default, True); 

  try

    Reader.ReadLine;

    while not Reader.EndOfStream do 

      begin

        for var Field in Reader.ReadLine.Split([','], '"') do 

          Writeln(Field.DeQuotedString('"'));   

        Writeln;                                                           

      end;

  finally

    Reader.Free;

  end;

  Readln;  

end.

执行结果：

Angel Fish

2

2

Computer Aquariums

Boa

10

8

South America

Critters

30

20

Screen Savers

House Cat

10

5

New Orleans

Ocelot

40

35

Africa and Asia

Parrot

5

5

South America

Tetras

2

2

Fish Bowls

使用 TStringList 进行文本分割的版本如下。

program ReadCSV;

{$APPTYPE CONSOLE}

{$R *.res}

uses

  System.Classes, System.SysUtils;

begin

  var Reader := TStreamReader.Create('animals.csv', TEncoding.Default, True); 

  var Fields := TStringList.Create;

  try

    Fields.StrictDelimiter := True;                  字 (TStringList.QuoteChar) は考慮される。

    Reader.ReadLine;                                                   

    while not Reader.EndOfStream do  

      begin

        Fields.DelimitedText := Reader.ReadLine;        

        for var Field in Fields do

          Writeln(Field);                                                         

        Writeln;   

      end;

  finally

    Fields.Free;

    Reader.Free;

  end;

  Readln;    

end.

导出 CSV 文件

说实话，写它的人并不是很特别。

写入CSV.dpr

program WriteCSV;

{$APPTYPE CONSOLE}

{$R *.res}

uses

  System.Classes, System.SysUtils, System.Types;

begin

  var Writer := TStreamWriter.Create('animals2.csv', False, TEncoding.UTF8);

  try

    var StrArr: TStringDynArray;

    SetLength(StrArr, 4);

    StrArr[0] := 'NAME'.QuotedString('"');

    StrArr[1] := 'SIZE'.QuotedString('"');

    StrArr[2] := 'WEIGHT'.QuotedString('"');

    StrArr[3] := 'AREA'.QuotedString('"');

    Writer.WriteLine(String.Join(',', StrArr));

    StrArr[0] := 'Angel Fish'.QuotedString('"');

    StrArr[1] := '2';

    StrArr[2] := '2';

    StrArr[3] := 'Computer Aquarium'.QuotedString('"');

    Writer.WriteLine(String.Join(',', StrArr));

  finally

    Writer.Free;

  end;

end.