怎么样读出文本文件中指定位置的内容？

Question

如：我想读出从每一行从第5列到第10列的内容，然后showmessage，能读吗？

Answer 1

给你一段文本编辑的程序！！
unit Unit1;interfaceuses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls, ComCtrls;type
    TForm1 = class(TForm)
        RichEdit1: TRichEdit;
        open: TButton;
        save: TButton;
        OpenDialog1: TOpenDialog;
        SaveDialog1: TSaveDialog;
        procedure openClick(Sender: TObject);
        procedure saveClick(Sender: TObject);
    private
    { Private declarations }
    public
    { Public declarations }
    end;var
    Form1: TForm1;
    filename: string;
implementation{$R *.dfm}procedure TForm1.openClick(Sender: TObject);
var
    ff: textfile;
    str: string;
begin
    richedit1.Clear;
    opendialog1.Execute;
    if opendialog1.FileName <> '' then
    begin
        filename := opendialog1.FileName;
        assignfile(ff, filename);
        reset(ff);
        while not Eof(ff) do
        begin
            readln(ff, str);
            richedit1.Lines.Add(str);
        end;
        closefile(ff);
    end;end;procedure TForm1.saveClick(Sender: TObject);
var
    ff: textfile;
    str: string;
    i: integer;
begin
    savedialog1.Execute;
    if savedialog1.FileName <> '' then
    begin
        filename := savedialog1.FileName;
        assignfile(ff, filename);
        rewrite(ff);
        for i := 0 to richedit1.Lines.Count do
        begin
            writeln(ff, richedit1.Lines[i]);
        end;
        closefile(ff);
    end;end;end.

Answer 2

如果是文本文件，简单的方法是：
Var
  FList: TStringList;
  tmpStr: String;
Begin
  FList:= TStringList.Create;
  FList.LoadFromFile(TextFileName);
  IF n < FList.Count Then begin
    tmpStr:= FList.Strings[5] + FList.Strings[6] + ... + FList.Strings[n];
    ShowMessage(tmpStr);
  End;
  FList.Free;
End;

Answer 3

FList.Strings[5] + FList.Strings[6] + ... + FList.Strings[n]读的是那一行的数据？具体表示什么？能解释一下吗？

Answer 4

ss:=memo1.lines.string[x];
sss:=copy(ss,5,5);