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Getting 400 exception in HttpWebRequest Call

I am using Postman to get the response from rest end point, and if I pass wrong data I am getting 400 exception which is very correct as per the logic.
But if I try to call the same web request from C# code(with same wrong parameter), I am getting exception but not the same as I am getting in Postman tool.
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://apiurl");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Headers.Add("Authorization", "Bearer " + token);
httpWebRequest.Method = "POST";
httpWebRequest.UserAgent = ".Net application";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = JsonConvert.SerializeObject(obj);//obj is parameter
streamWriter.Write(json);
}
try
{
HttpWebResponse httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
}
}
catch (WebException e)
{
}
Can I know why I am getting errors differently from postman and C# code
Regards
Anand

Added below code in the exception block and it gave me the same response as Postman
catch(WebException ex)
{
string message = ex.Message;
WebResponse errorResponse = ex.Response;
if (errorResponse != null)
{
using (Stream responseStream = errorResponse.GetResponseStream())
{
StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
message = reader.ReadToEnd();
}
}
}

How to capture a response token sent by a REST API after a request?

I am working on consuming a REST API and I am using basic authentication where password is encoded to Base64 as follows
private XmlDocument sendXMLRequest(string requestXml)
{
string destinationUrl = "https://serviceapi.testgroup.com/testtp/query";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destinationUrl);
request.Headers["Authorization"] = "Basic " + Convert.ToBase64String(Encoding.Default.GetBytes("API_TEST_NR:Testnol1$"));
byte[] bytes;
bytes = System.Text.Encoding.ASCII.GetBytes(requestXml);
request.Method = "POST";
request.ContentLength = bytes.Length;
//request.Connection = "keep-alive";
request.ContentType = "text/xml";
request.KeepAlive = true;
request.Timeout = 2000;
request.MediaType = "text/xml";
Stream requestStream = request.GetRequestStream();
requestStream.Write(bytes, 0, bytes.Length);
requestStream.Close();
HttpWebResponse response;
Stream responseStream;
using (response = (HttpWebResponse)request.GetResponse())
{
if (response.StatusCode == HttpStatusCode.OK)
{
responseStream = response.GetResponseStream();
XmlReader reader = new XmlTextReader(responseStream);
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(reader);
try { reader.Close(); }
catch { }
try { responseStream.Close(); }
catch { }
try { response.Close(); }
catch { }
return xmlDoc;
}
}
try { response.Close(); }
catch { }
return null;
}
I'm kind of new to working on Web Api's and I know that the API responds with an access x-token after successful authorization based on the API documentaion and I am not sure how to access or capture it from the HTTP headers.
May I know a good way I can achieve this?

This is easier than I thought just capturing with its name.
string xtoken= response.Headers["custom-header"];
Console.WriteLine(xtoken);

Try this as below, represents, Request Data Using the WebRequest Class.In most cases, the WebRequest class is sufficient to receive data. However, if you need to set protocol-specific properties, you must cast the WebRequest to the protocol-specific type. For example, to access the HTTP-specific properties of HttpWebRequest, cast the WebRequest to an HttpWebRequest reference.
private XmlDocument GetRootLevelServiceDocument(
string serviceEndPoint, string oAuthToken)
{
XmlDocument xmlDoc = new XmlDocument();
HttpWebRequest request = CreateHttpRequest(serviceEndPoint,
oAuthToken);
using (HttpWebResponse response =
(HttpWebResponse)request.GetResponse())
{
using (XmlReader reader =
XmlReader.Create(response.GetResponseStream(),
new XmlReaderSettings() { CloseInput = true }))
{
xmlDoc.Load(reader);
string data = ReadResponse(response);
if (response.StatusCode != HttpStatusCode.OK)
{
LogMsg(string.Format("Error: {0}", data));
LogMsg(string.Format(
"Unexpected status code returned: {0}",
response.StatusCode));
}
}
}
return xmlDoc;
}

Call Genderize.io API From C#

I'm trying to call http://genderize.io/ , but i'm getting an error from .NET saying:
{"You must provide a request body if you set ContentLength>0 or SendChunked==true. Do this by calling [Begin]GetRequestStream before [Begin]GetResponse."}
How would I call this web service "http://api.genderize.io/?name=peter" from C# and get a JSON string back?
HttpWebRequest request;
string postData = "name=peter"
URL = "http://api.genderize.io/?"
Uri uri = new Uri(URL + postData);
request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = postData.Length;
request.AllowAutoRedirect = true;
UTF8Encoding enc = new UTF8Encoding();
string result = string.Empty;
HttpWebResponse Response;
try
{
using (Response = (HttpWebResponse)request.GetResponse())
{
using (Stream responseStream = Response.GetResponseStream())
{
using (StreamReader readStream = new StreamReader(responseStream, Encoding.UTF8))
{
return readStream.ReadToEnd();
}
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Error: " + ex.Message);
throw ex;
}

You are making the call to the service using POST method, reading through the comments area in http://genderize.io/ the author states that only GET method requests are allowed.
Stroemgren: Yes, this is confirmed. Only HTTP GET request are allowed.
This answer probably would be better as a comment, but I don't have enough reputation :(

How to Call a WebService without using WebReference?

I want to know if there is someone who had use a Class to Call a WebService, this WS receives an integer after the organizational references and responds into a json file,
Actually my issue is to call the webservice without using a webreference, and read the json file and parse it into a dictionary ,
I appreciate your help
Best Regards, i let you my code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Net;
using Dimex.ChangeSAP.Core.Utilities;
namespace Dimex.ChangeSAP.Core.Utilities
{
class ConsumirWebService
{
public void ConsumirWS()
{
Dimex.ChangeSAP.Core.Entities.Seguridad.Usuario users = new Dimex.ChangeSAP.Core.Entities.Seguridad.Usuario();
int idUsuaro = users.IdUsuario;
try
{
System.Net.WebRequest req = System.Net.WebRequest.Create("http://192.168.8.97/PassportPruebas/api/partners?enterprise_system_id=1&organizational_reference=" + idUsuaro);
//req.Proxy = new System.Net.WebProxy(ProxyString, true);
//Add these, as we're doing a POST
req.ContentType = "application/x-www-form-urlencoded";
req.Method = "POST";
//We need to count how many bytes we're sending.
//Post'ed Faked Forms should be name=value&
string postData = "OPERATION_NAME=ADD_REQUEST&TECHNICIAN_KEY=90BA&INPUT_DATA=" + sendXML;
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(postData);
req.ContentLength = bytes.Length;
System.IO.Stream os = req.GetRequestStream();
os.Write(bytes, 0, bytes.Length); //Push it out there
os.Close();
System.Net.WebResponse resp = req.GetResponse();
if (resp == null)
{
return null;
}
System.IO.StreamReader sr =
new System.IO.StreamReader(resp.GetResponseStream());
string respuesta = sr.ReadToEnd().Trim();
return respuesta;
}
catch (Exception ex)
{
return "";
//throw or return an appropriate response/exception
}
}
}
}

Well Actually here is my code for anyone with this kind of issue too,
public static string LlamarWebService(string url)
{
try
{
System.Net.WebRequest req = System.Net.WebRequest.Create(url);
req.ContentType = "application/json";
req.Method = "GET";
System.Net.WebResponse resp = req.GetResponse();
if (resp == null) return null;
System.IO.StreamReader sr =
new System.IO.StreamReader(resp.GetResponseStream());
string respuesta = sr.ReadToEnd().Trim();
return respuesta;
}
catch (Exception ex)
{
throw ex;
// return "";
//throw or return an appropriate response/exception
}
}

you can create a proxy class using wsdl utility or svcutil in visualstudiocommand prompt enter command wsdl.exe /out:[path and name of the file] /language:CS

httpwebrequest gives timeout until restarted

I am working on a desktop application developed in C# (.NET environment).
This application connects to remote server using HttpWebRequest. If due to any reason my PC is disconnected from the internet and I re-connect it my application always gives request timeout for HttpWebRequest until I restart my whole application and if I again add new thread to my application after network d/c it works fine.
Is there any way to reset my network or anyone can tell me how does it work?
//my code is..
public String request(String add, String post, int time, String reff, int id, int rwtime)
{
try
{
if (rwtime == 0)
{
rwtime = 100000;
}
string result = "";
string location = "";
// Create the web request
HttpWebRequest req = WebRequest.Create(add) as HttpWebRequest;
req.ReadWriteTimeout = rwtime;
req.KeepAlive = true;
req.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate");
req.Accept = "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5";
req.ContentType = "application/x-www-form-urlencoded";
req.Timeout = time;
req.Referer = reff;
req.AllowAutoRedirect = false;
req.CookieContainer = statictk.cc[id];
req.PreAuthenticate = true;
if (post != "")
{
req.Method = "POST";
string postData = post;
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] byte1 = encoding.GetBytes(postData);
// Set the content type of the data being posted.
req.ContentType = "application/x-www-form-urlencoded";
// Set the content length of the string being posted.
req.ContentLength = byte1.Length;
Stream newStream = req.GetRequestStream();
newStream.Write(byte1, 0, byte1.Length);
newStream.Close();
}
else
{
req.Method = "GET";
}
// Get response
try
{
HttpWebResponse response = req.GetResponse() as HttpWebResponse;
// Get the response stream
location = response.GetResponseHeader("Location");
if (location == "")
{
Stream responseStream = response.GetResponseStream();
if (response.ContentEncoding.ToLower().Contains("gzip"))
responseStream = new GZipStream(responseStream, CompressionMode.Decompress);
else if (response.ContentEncoding.ToLower().Contains("deflate"))
responseStream = new DeflateStream(responseStream, CompressionMode.Decompress);
StreamReader reader = new StreamReader(responseStream, Encoding.Default);
// Read the whole contents and return as a string
result = reader.ReadToEnd();
}
else
{
result = location;
}
response.Close();
if (result == "") result = "retry";
return result;
}
catch (Exception e)
{
log.store("errorinresponce", e.Message);
if (statictd.status[id] != "removed")
{
return "retry";
}
else
{
return "error";
}
}
}
catch(Exception f)
{
log.store("Networkerrorretry", f.Message);
if (f.Message == "The operation has timed out")
{
return "retry";
}
string ans = MessageBox.Show("There was a Network Error..Wish to Retry ?\nError msg : "+ f.Message, "Title", MessageBoxButtons.YesNo).ToString();
if (ans == "Yes")
return "retry";
else
{
Invoketk.settxt(id, "Not Ready");
return "error";
}
}
}

It sounds like your application is missing some error handling. A disconnect can happen at any time and your application should be able to handle it. Try to surround the network loop with a try-catch statement, and then catch for the different kinds of exceptions. Depending on what exception was thrown, you can then decide if you reconnect to the server silently or if you want to generate an error message.