1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:

procedure TForm1.Button2Click(Sender: TObject);
var i : integer;
  data : string;
  file1 : textfile;

label zur;
begin
i := 1;
assignfile(file1, ExtractFilePath(ParamStr(0)) + 'wtm.dat');//, file1);
Reset(file1);

zur:
i := i + 1;
data := ListBox1.items[i];
writeln(data);
If not (i = 500) then goto zur;
//If not (ListBox1.items.count=-1) then goto zur;
CloseFile(file1);
end;					

1:

WriteLN (file1, data);					

1:
2:

For Idx := 0 To ListBox1.Items.Count -1 Do
  WriteLn (File1, ListBox1.Items [Idx]);					

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:

procedure SaveListBoxItems;
var Stream: TFileStream;
    i: Integer;
    LbItemLength: LongInt;
    LbCount: LongInt;
begin
  Stream := TFileStream.Create(ExtractFilePath(ParamStr(0)) + 'LB_Items.dat',
                                fmCreate);

  try
    LbCount := ListBox1.Count - 1;
    Stream.Write(LbCount, SizeOf(LbCount));

    For i := 0 to LbCount do
    begin
      LbItemLength := Length(ListBox1.Items[i]);
      Stream.Write(LbItemLength, SizeOf(LbItemLength));
      Stream.Write(PChar(ListBox1.Items[i])^, LbItemLength);
    end;
  finally
    Stream.Free;
  end;
end;