具有方法发布的HttpWebRequest

Question

我有此链接：http://www2.correios.com.br/sistemas/rastreamento/

并且需要填充textarea并为它使用subit按钮，这需要使用以下代码：

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www2.correios.com.br/sistemas/rastreamento/ctrl/ctrlRastreamento.cfm");
        request.CookieContainer = new CookieContainer();
        request.Method = "POST";
        string postData = "objetos=PU633524761BR";
        byte[] byteArray = Encoding.UTF8.GetBytes(postData);
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = byteArray.Length;
        Stream dataStream = request.GetRequestStream();
        dataStream.Write(byteArray, 0, byteArray.Length);
        dataStream.Close();




        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        dataStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(dataStream);
        string responseFromServer = reader.ReadToEnd();
        Console.WriteLine(responseFromServer);
        textBox.Text = responseFromServer;
        dataStream.Close();

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