Code:

unit MsFormR;

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

StdCtrls, ExtCtrls;

type

TForm1 = class(TForm)

   OpenDialog1: TOpenDialog;

   SaveDialog1: TSaveDialog;

   Memo1: TMemo;

   ListBox1: TListBox;

   Panel1: TPanel;

   Button1: TButton;

   Button2: TButton;

   Splitter1: TSplitter;

   procedure FormCreate(Sender: TObject);

   procedure Button1Click(Sender: TObject);

   procedure Button2Click(Sender: TObject);

private

   MemStr1: TMemoryStream;

public

   procedure ShowMemStr;

end;

var

Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);

begin

MemStr1 := TMemoryStream.Create;

end;

procedure TForm1.Button1Click(Sender: TObject);

var

Str1: TFileStream;

begin

OpenDialog1.Filter :=

   'Any file (*.*)|*.*';

OpenDialog1.DefaultExt := '*';

if OpenDialog1.Execute then

begin

   Str1 := TFileStream.Create (

     OpenDialog1.Filename, fmOpenRead);

   try

     MemStr1.LoadFromStream (Str1);

     ShowMemStr;

     Button2.Enabled := true;

   finally

     Str1.Free;

   end;

end;

end;

procedure TForm1.ShowMemStr;

begin

Memo1.Lines.LoadFromStream (MemStr1);

end;

procedure TForm1.Button2Click(Sender: TObject);

const

ndx: LongInt = 1;

var

pch:  PChar;

tmpC: Char;

begin

pch := MemStr1.Memory;

tmpC := pch[ndx];

pch[ndx] := #0;

ListBox1.Items.SetText(MemStr1.Memory);

pch[ndx] := tmpC;

if ndx < MemStr1.Size then

   Inc(ndx)

else

   Button2.Enabled := False;

end;

end.