Lenguaje de programación Borland Delphi
Os mostramos una función en Delphi para comprobar la validez de la sintaxis de una direción de correo electrónico (email):
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, shellapi;
type
TformComprobarEmail = class(TForm)
txtEmail: TEdit;
lResultado: TLabel;
bComprobar: TButton;
Label2: TLabel;
LWEB: TLabel;
procedure bComprobarClick(Sender: TObject);
procedure LWEBClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
formComprobarEmail: TformComprobarEmail;
implementation
{$R *.DFM}
function emailCorrecto (const email: string): Boolean;
function comprobar (const s: string): Boolean;
var
i : Integer;
begin
Result := false;
for i := 1 to Length(s) do
if not (s[i] in ['a'..'z', 'A'..'Z', '0'..'9', '_', '-', '.']) then
Exit;
Result := true;
end;
var
i : Integer;
nombre, servidor : string;
begin
Result := False;
i := Pos('@', email);
if i = 0 then
Exit;
nombre := Copy(email, 1, i-1);
servidor := Copy(email, i + 1, Length(email));
if (Length(nombre) = 0) or ((Length(servidor) < 5)) then
Exit;
i := Pos('.', servidor);
if (i = 0) or (i > (Length(servidor) - 2)) then
Exit;
Result := comprobar (nombre) and comprobar (servidor);
end;
procedure TformComprobarEmail.bComprobarClick(Sender: TObject);
begin
if emailCorrecto (txtEmail.Text) then
lResultado.Caption := 'Correcto'
else
lResultado.Caption := 'Incorrecto';
end;
procedure TformComprobarEmail.LWEBClick(Sender: TObject);
begin
ShellExecute(Handle, Nil, PChar(LWEB.CAPTION),
Nil, Nil, SW_SHOWNORMAL);
end;
end.
Publicado el: 2006-03-05