错误流不可写

Question

我遇到错误

var streamWriter = new StreamWriter（httpWebRequest.GetRequestStream（））

在第二步循环----＆gt; “错误流不可写。”

 private void button1_Click(object sender, EventArgs e)
    {
        List<string> names = new List<string>();
        names.Add("ali");
        names.Add("hassan");
        names.Add("mohamad");
        var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://localhost:8080/ServiceTest/adperson");
        httpWebRequest.ContentType = "application/json";
        httpWebRequest.Method = "POST";
        foreach (string item in names)
        {
            try
            {
                using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
                {
                    string json = new JavaScriptSerializer().Serialize(new
                                    {
                                        Name = item,
                                        CodeMeli = "005"
                                    });
                    streamWriter.Write(json);
                    streamWriter.Flush();
                    streamWriter.Close();
                }
                HttpWebResponse httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();

                using (StreamReader streamReader = new StreamReader(httpResponse.GetResponseStream()))
                {
                    var result = streamReader.ReadToEnd();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

请帮助。 感谢。