OnGetAsync(string paramUsername, string paramPassword)
        {
            string returnUrl = Url.Content("~/");

            try
            {
                // Clear the existing external cookie
                await HttpContext
                .SignOutAsync(
                    CookieAuthenticationDefaults.AuthenticationScheme);
            }
            catch { }
            // *** !!! This is where you would validate the user !!! ***
            // In this example we just log the user in
            // (Always log the user in for this demo)

            if (UsuariosController.InicioSesion(paramUsername, paramPassword))
            {
                var claims = new List <Claim>
                {
                    new Claim(ClaimTypes.Name, paramUsername),
                    new Claim(ClaimTypes.Role, UsuariosController.GetRol(paramUsername))
                };
                var claimsIdentity = new ClaimsIdentity(
                    claims, CookieAuthenticationDefaults.AuthenticationScheme);

                var authProperties = new AuthenticationProperties
                {
                    IsPersistent = true,
                    RedirectUri  = this.Request.Host.Value
                };
                try
                {
                    await HttpContext.SignInAsync(
                        CookieAuthenticationDefaults.AuthenticationScheme,
                        new ClaimsPrincipal(claimsIdentity),
                        authProperties);
                }
                catch (Exception ex)
                {
                    string error = ex.Message;
                }
            }



            return(LocalRedirect(returnUrl));
        }