public void Incluir(ModeloCategoria modelo)
{
SqlCommand cmd = new SqlCommand();
cmd.Connection = conexao.ObjetoConexao;
cmd.CommandText = "insert into categoria(cat_nome) values (@nome); select @@IDENTITY;";
cmd.Parameters.AddWithValue("@nome", modelo.CatNome);
conexao.Conectar();
modelo.CatCod = Convert.ToInt32(cmd.ExecuteScalar());
conexao.Desonectar();
}