How could I validate the fields below so they do not go blank, as my biggest difficulty is that two of them have Convert.
NegocioFuncionario neg = new NegocioFuncionario();
EntidadeFuncionario ent = new EntidadeFuncionario();
ent.Matricula = Convert.ToInt32(txtMatricula.Text);
ent.DataNascimento = Convert.ToDateTime(txtNascimento.Text);
ent.Nome = txtNome.Text;
ent.Situacao = cboSituacao.SelectedItem.ToString();