unit Unit1;

interface

uses

  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type

  TForm1 = class(TForm)

    Edit1: TEdit;

    Button1: TButton;

    procedure Button1Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

uses  IdHTTP,

  IdStack;

function GetExternalIP(UrlIpAddress:string): string;

var

  lHTTP  : TIdHTTP;

  lStream: TStringStream;

begin

  lHTTP   := TIdHTTP.Create(nil);

  lStream := TStringStream.Create(Result);

  try

    try

      lHTTP.Get(UrlIpAddress, lStream);

      lStream.Seek(0,0);

      Result := lStream.ReadString(lStream.Size);

    except

      Result:='';

    end;

  finally

    FreeAndNil(lHTTP);

    FreeAndNil(lStream);

  end;

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

edit1.Text:=GetExternalIP('http://ip.hao828.com/ip.asp');

end;

end.