unit Unit11;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm11 = class(TForm)
    edt1: TEdit;
    btn1: TButton;
    edt2: TEdit;
    btn2: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    function ip2Int(const strIP: string): Int64;
    function int2Ip(intIP: Int64): string;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form11: TForm11;

implementation

{$R *.dfm}

function TForm11.int2Ip(intIP : Int64) : string;
var
  n : int64;
begin
  Result := '';
  n := intIP shr 24;
  intIP := intIP xor (n shl 24);
  Result := IntToStr(n) + '.';

  n := intIP shr 16;
  intIP := intIP xor (n shl 16);
  Result := Result + IntToStr(n) + '.';

  n := intIP shr 8;
  intIP := intIP xor (n shl 8);
  Result := Result + IntToStr(n) + '.';

  n := intIP;
  Result := Result + IntToStr(n);
end;

function TForm11.ip2Int(const strIP : string): Int64;
var
  lst : TStringList;
  i : integer;
begin
  result := 0;
  lst := TStringList.Create;
  try
    lst.Delimiter := '.';
    lst.DelimitedText := strIP;

    for i := 0 to lst.Count - 1 do
      result := result + StrToInt64(lst[i]) shl (24 - i * 8);
  finally
    lst.Free;
  end;
end;

procedure TForm11.btn1Click(Sender: TObject);
begin
  edt2.Text := IntToStr(ip2Int(edt1.Text));
end;

procedure TForm11.btn2Click(Sender: TObject);
begin
  edt1.Text := int2Ip(StrToInt64(edt2.Text));
end;

procedure TForm11.FormCreate(Sender: TObject);
begin
  edt1.Text := '192.168.1.1';
  btn1.Click;
end;

end.