Client.Sefaz.Net Api de Download de XML (NF-e Versão 3.10 / 4.00) Api = new Client.Sefaz.Net.Api(); using (var ms = new MemoryStream(Api.Captcha())) { pictureBox1.Image = Image.FromStream(ms); } var DadosPagina = Api.ConsultaToXml(_Chave, txtCaptcha.Text);