请教!(急!急!急!急!)

Question

我用Opendialog打开一个txt文件,读取里面的数据,然后做一些修改,最后写到另一个txt文件中(有固定的路径),可是等我处理完后,发现原来的那个txt文件也被改变了,怎么回事啊?Opendialog的path为全局变量.请高手指教,谢谢!

Answer 1

unit Unit3;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, DB, DBTables, Grids, DBGrids, ADODB, ComCtrls;type
  TForm3 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    Button3: TButton;
    Button4: TButton;
    OpenDialog1: TOpenDialog;
    SaveDialog1: TSaveDialog;
    Table1: TTable;
    ProgressBar1: TProgressBar;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
   private
    { Private declarations }
  public
    { Public declarations }  end;var
  Form3: TForm3;
  path:String;//因为多个按钮都要用到path的值
implementationuses Unit4, import;{$R *.dfm}procedure TForm3.Button1Click(Sender: TObject);
var
  Form1: TForm;
  sl: TStringList;
  infile:textfile;
  j,i: integer;
  s,d,ss,fname,instring: string;
begin
   button3.click;
    fname:='D:\editransform1\data.txt';
    assignfile(infile,fname);
    rewrite(infile);    //利用rewrite清空原文本
   // append(infile);
   // instring:='';
   // writeln(infile,instring);
    closefile(infile);
  sl := TStringList.Create;
  sl.LoadFromFile(path);
  progressbar1.Min:=0;
  progressbar1.Max:=sl.Count;
  progressbar1.Step:=1;
  for i:=0 to sl.Count-1 do
  begin
    progressbar1.Position:=i;
    s:=sl[i];
    for j:=0 to Length(s) do
    begin
    if ((s[j]='?') and (s[j+1]='?')) then
    begin
    s[j]:=' ';
    d:=copy(s,1,j);
    ss:=copy(s,j+2,Length(s));
    s:=d+ss;
    end;
    end;
    fname:='D:\editransform1\data.txt';
    assignfile(infile,fname);
    //rewrite(infile);
    append(infile);
    instring:=s;
    writeln(infile,instring);
    closefile(infile);
  end;
  Form3.Hide;
  Form1:=TForm1.create(Application);
  Form1.ShowModal;
  end;procedure TForm3.Button2Click(Sender: TObject);
begin
application.Terminate;
end;procedure TForm3.Button3Click(Sender: TObject); //去掉文件中的空行
var
s,d:Tstringlist;
i,j:integer;
ss,l:String;
begin
opendialog1.Execute;
path:=opendialog1.Files[0];
s:=Tstringlist.Create;
d:=Tstringlist.Create;
//s.LoadFromFile('D:\editransform1\data1.txt');
s.LoadFromFile(path);//读取原始报文
for i:=0 to s.Count-1 do
begin
  ss:=s[i];
  l:=copy(ss,1,2);
  if ((length(s[i])<5) or (l='47')) then
  else
  d.Add(s[i]);
end;
 //d.SaveToFile('D:\editransform1\data1.txt');
 d.SaveToFile(path);
end;procedure TForm3.Button4Click(Sender: TObject);
var
  s: string;
  sl:Tstringlist;
  i:integer;
begin
  sl := TStringList.Create;
  sl.LoadFromFile('D:\editransform1\data5.txt');
  for i:=0 to sl.Count-1 do
  begin
    s:=sl[i];
    Table1.Active:=True;
    Table1.Append;
    Table1.Fields[0].AsString:=s;
    Table1.Post;
  end;end;end.

Answer 2

又用TStringList，又用writeln写文件，看到头晕了....
自己跟踪一下，看看是不是这里将path文件给覆盖了
s.LoadFromFile(path);
....
d.SaveToFile(path);

Answer 3

我跟踪了一下,button1中的s在变得时候,button3中的s也跟着变,又不是全局变量,怎么会变呢?