private void Logout()
{
App.Current.Properties["IsLoggedIn"] = Boolean.FalseString;
Application.Current.SavePropertiesAsync();
string cpf = Xamarin.Forms.Application.Current.Properties["Cpf_user"].ToString();
conexao.RemoveUsuario(cpf);
App.Current.Properties["Cpf_user"] = "";
App.Current.MainPage = new CarroselLogin();
}
