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C# JSON Post using HttpWebRequest

I am new to JSON and C# and trying to write a code that will perform an http web request POST to get a token. Below is my code but I keep getting 400 bad request. Probably my codes just incorrect and I will appreciate for any helps on this. Below is my codes :
static public string GetAuthorizationToken()
{
string token = string.Empty;
string requestUrl = "some URL";
HttpWebRequest httpWebRequest = WebRequest.Create(requestUrl) as HttpWebRequest;
httpWebRequest.Method = "POST";
httpWebRequest.ContentType = "x-www-form-urlencoded";
Dictionary<string, string> postParameters = new Dictionary<string, string>();
postParameters.Add("grant", "some credentials");
postParameters.Add("id", "1234123411");
postParameters.Add("secret", "1234123411");
postParameters.Add("scope", "abcd");
string postData = "";
foreach (string key in postParameters.Keys)
{
postData += WebUtility.UrlEncode(key) + "="
+ WebUtility.UrlEncode(postParameters[key]) + "&";
}
byte[] data = Encoding.ASCII.GetBytes(postData);
httpWebRequest.ContentLength = data.Length;
Stream requestStream = httpWebRequest.GetRequestStream();
requestStream.Write(data, 0, data.Length);
requestStream.Close();
TokenResponse tokenResponse = new TokenResponse();
using (HttpWebResponse response = httpWebRequest.GetResponse() as HttpWebResponse)
{
if (response.StatusCode != HttpStatusCode.OK)
throw new Exception(String.Format(
"Server error (HTTP {0}: {1}).",
response.StatusCode,
response.StatusDescription));
DataContractJsonSerializer responseSerializer = new DataContractJsonSerializer(typeof(TokenResponse));
Stream responseStream = response.GetResponseStream();
object objResponse = responseSerializer.ReadObject(responseStream);
tokenResponse = objResponse as TokenResponse;
response.Close();
if (tokenResponse != null)
{
return tokenResponse.accessToken;
}
}
return token;
}

Here is a precise and accurate example of a POST request and reading the response(though without serializing the JSON data). Only mistake I see so far in your code is an incorrect ContentType also we can't see what url you are trying to send the server(but odds are that it is incorrect). Hope it helps you advance.
using System;
using System.Collections.Generic;
using System.Net;
using System.IO;
namespace SExperiment
{
class MainClass
{
public static void Main(string[] args)
{
try{
string webAddr="http://gurujsonrpc.appspot.com/guru";
var httpWebRequest = WebRequest.CreateHttp(webAddr);
httpWebRequest.ContentType = "application/json; charset=utf-8";
httpWebRequest.Method = "POST";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = "{ \"method\" : \"guru.test\", \"params\" : [ \"Guru\" ], \"id\" : 123 }";
streamWriter.Write(json);
streamWriter.Flush();
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var responseText = streamReader.ReadToEnd();
Console.WriteLine(responseText);
//Now you have your response.
//or false depending on information in the response
}
}catch(WebException ex){
Console.WriteLine(ex.Message);
}
}
}
}

You have set requestUrl to "some URL". Please try with a web address that exists, in addition to changing the content type to "application/json".

How I can pass Json from Win Forms to MVC Controller

I have MVC Controller given below:
public ActionResult ReceiveJson(string json)
{
//--
return Content(json, "application/json");
}
I created Windows Forms Application. In the application I want to pass Json to my MVC Controller.
I use:
string json = new JavaScriptSerializer().Serialize(myObject);
using (var client = new CookieAwareWebClient())
{
var values = new NameValueCollection
{
{ "username", login },
{ "password", haslo },
};
client.UploadValues("http://localhost/xxxxx/Login", values);
string link = "http://localhost/xxx/ReceiveJson";
client.Headers.Add("Content-Type", "application/json");
var response = client.UploadString(new Uri (link), "POST", json);
}
This code doesn't work. In ReceiveJson Controller I received null.
http://s22.postimg.org/9vxu2no9t/json.jpg
Can you tell me how I can pass Json from Win Forms to MVC Controller?
Thanks ;-)

Here is working code example:
var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://localhost/CONTROLLER_NAME/ReceiveJson");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "GET";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = new JavaScriptSerializer().Serialize(myObject);
streamWriter.Write(json);
streamWriter.Flush();
streamWriter.Close();
// If you need to read response
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
}
}

have you checked your json value before send it?
Have you tried to uploadstring without adding extra header? In your action you receave string not an object. Here is a good example.

Looks like you violated some MVC conventions.
First you should post your values in request body not in JSON. It will look like this
using(var content = new MultipartFormDataContent())
{
content.Add(new StringContent(firstPropertyName), "firstValue");
content.Add(new StringContent(secondPropertyName), "secondValue");
client.PostAsync("https://mydomain.com/xxx/ReceiveJson", content);
}
Second you should mark your Action with [HttpPost] attribute
Third you should try to receive your viewModel not a string. It will simplify your code on the server
I believe it will help.

It's a good working version:
public ActionResult NamiaryWyZapis()
{
Stream jsonDane = Request.InputStream;
jsonDane.Seek(0, System.IO.SeekOrigin.Begin);
string json = new StreamReader(jsonDane).ReadToEnd();
//--
}

ANSWER: Via POST.
You need to serialize your object(on this case Persons) to json and make a post with a method like this one. (Person model must be accessible from both applications)
public async bool SendRequestAsync(string requestUrl, object data)
{
string json = JsonConvert.SerializeObject(obj, Formatting.Indented,
new JsonSerializerSettings
{
ReferenceLoopHandling = ReferenceLoopHandling.Ignore
});
try
{
HttpWebRequest request = WebRequest.Create(requestUrl) as HttpWebRequest;
if (request != null)
{
request.Accept = "application/json";
request.ContentType = "application/json";
request.Method = "POST";
using (var stream = new StreamWriter(await request.GetRequestStreamAsync()))
{
stream.Write(json);
}
using (HttpWebResponse response = await request.GetResponseAsync() as HttpWebResponse)
{
if (response != null && response.StatusCode != HttpStatusCode.OK)
throw new Exception(String.Format(
"Server error (HTTP {0}: {1}).",
response.StatusCode,
response.StatusDescription));
if (response != null)
{
Stream responseStream = response.GetResponseStream();
//return true or false depending on the ok
return GetResponseModel(responseStream);
}
}
}
}
catch (WebException ex)
{
var response = ex.Response;
Stream respStream = response.GetResponseStream();
//return true or false depending on the ok
return GetResponseModel(respStream);
}
catch (Exception e)
{
return false;
}
return false;
}
The GetResponseModel method returns the model that you want to read from the web if your POST was success. Then in your WinForms you can register that success if you want.
The controller method will look like this one
[HttpPost]
public ActionResult JsonMethod(Person p)
{
if(p != null)
return Json(true);
else return Json(false);
}
The body of your GetResponse could be like this one
public static T GetResponseModel<T>(Stream respStream) where T : class
{
if (respStream != null)
{
var respStreamReader = new StreamReader(respStream);
Task<string> rspObj = respStreamReader.ReadToEndAsync();
rspObj.Wait();
T jsonResponse = JsonConvert.DeserializeObject<T>(rspObj.Result);
return jsonResponse;
}
return default(T);
}

Adding parameters to an HttpWebRequest

This question has been asked a million times, and yet none of the responses work for me. The one I was most excited about was Http Post for Windows Phone 8 but because it requires delegates, it's not right for my code... the Postdata function is called from repositories, it would be nice to get a response straight from this function!
How do I add post parameters to this code? I've been trying to get it to work for a good 10 hours now.
// Repository code
string url = "/bla/bla/" + blaId + "/";
Dictionary<string, string> postParams = new Dictionary<string, string>();
postParams.Add("value", message);
string response = await BlaDataContext.PostData(url, postParams);
// ...
public static async Task<string> PostData(string url, Dictionary<String, String> postParams)
{
HttpWebRequest request = WebRequest.CreateHttp(APIURL + url);
request.ContentType = "application/x-www-form-urlencoded";
request.Method = "POST";
postParams.Add("oauth_token", Contract.AccessToken); // where do I add this to the request??
try
{
HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync();
Debug.WriteLine(response.ContentType);
Stream responseStream = response.GetResponseStream();
string data;
using (var reader = new StreamReader(responseStream))
{
data = reader.ReadToEnd();
}
responseStream.Close();
return data;
}
catch (Exception e)
{
// whatever
}
}

HttpWebRequest request = WebRequest.CreateHttp("" + url);
//we could move the content-type into a function argument too.
request.ContentType = "application/x-www-form-urlencoded";
request.Method = "POST";
postParams.Add("oauth_token", ""); // where do I add this to the request??
try
{
//this is how you do it
using(var stream = await request.GetRequestStreamAsync())
{
byte[] jsonAsBytes = Encoding.UTF8.GetBytes(string.Join("&", postParams.Select(pp => pp.Key + "=" + pp.Value)));
await stream.WriteAsync(jsonAsBytes, 0, jsonAsBytes.Length);
}
HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync();
Debug.WriteLine(response.ContentType);
System.IO.Stream responseStream = response.GetResponseStream();
string data;
using (var reader = new System.IO.StreamReader(responseStream))
{
data = reader.ReadToEnd();
}
responseStream.Close();
return data;
}
Async Await HttpWebRequest Extensions:
public static class HttpExtensions
{
public static Task<Stream> GetRequestStreamAsync(this HttpWebRequest request)
{
var tcs = new TaskCompletionSource<Stream>();
try
{
request.BeginGetRequestStream(iar =>
{
try
{
var response = request.EndGetRequestStream(iar);
tcs.SetResult(response);
}
catch (Exception exc)
{
tcs.SetException(exc);
}
}, null);
}
catch (Exception exc)
{
tcs.SetException(exc);
}
return tcs.Task;
}
public static Task<HttpWebResponse> GetResponseAsync(this HttpWebRequest request)
{
var taskComplete = new TaskCompletionSource<HttpWebResponse>();
request.BeginGetResponse(asyncResponse =>
{
try
{
HttpWebRequest responseRequest = (HttpWebRequest)asyncResponse.AsyncState;
HttpWebResponse someResponse =
(HttpWebResponse)responseRequest.EndGetResponse(asyncResponse);
taskComplete.TrySetResult(someResponse);
}
catch (WebException webExc)
{
HttpWebResponse failedResponse = (HttpWebResponse)webExc.Response;
taskComplete.TrySetResult(failedResponse);
}
}, request);
return taskComplete.Task;
}
}
With the extensions, I think it's a little cleaner.

You need to write the parameters to the request body.
You could use an extension method like this one:
public static void AddFormData(this HttpWebRequest request, IDictionary<string, string> data)
{
using (var memStream = new MemoryStream())
using (var writer = new StreamWriter(memStream))
{
bool first = true;
foreach (var d in data)
{
if (!first)
writer.Append("&");
writer.Write(Uri.EscapeDataString(d.Key));
writer.Write("=");
writer.Write(Uri.EscapeDataString(d.Value));
first = false;
}
writer.Flush();
request.ContentLength = memStream.Length;
memStream.Position = 0;
using (var reqStream = request.GetRequestStream())
{
memStream.CopyTo(reqStream);
}
}
}
Call it like this:
request.AddFormData(postParams);

WP8 HttpWebRequest Post Not Working

I have a Windows Phone Application and I I am trying to post data in JSON format to a WCF application. Although the connection is made, the server returns with a custom message with
This is the C# code:
ReportSightingRequest.Instance.Source = Source.IPhone;
var jsonData = JsonConvert.SerializeObject(ReportSightingRequest.Instance);
var uri = new Uri("urlGoesHere", UriKind.Absolute);
var request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/json";
request.ContentLength = jsonData.Length;
string received;
using (var response = (HttpWebResponse)(await Task<WebResponse>.Factory.FromAsync(request.BeginGetResponse, request.EndGetResponse, null)))
{
using (var responseStream = response.GetResponseStream())
{
using (var sr = new StreamReader(responseStream))
{
received = await sr.ReadToEndAsync();
}
}
}
This is the WCF Interface:
[OperationContract]
[WebInvoke(Method = "POST", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
[Description("Description.")]
Response.Response ReportSighting(ReportSightingRequest sighting);
This is the implementation:
public Response ReportSighting(ReportSightingRequest sightingRequest)
{
var response = new Response();
if (sightingRequest == null || sightingRequest.TypeId == null)
{
response.Status = ResponseStatus.InvalidArguments;
response.Message = "Request is null or no type has been supplied.";
return response;
}
...
}
When I call the ReportSighting method form the phone, I get a "Request is null or no type has been supplied" message. The strange thing is that I AM sending a TypeId and the sightingRequest object on the WP8 side is definitely not null when i'm sending it. When I put a breakpoint on the jsonData, it has everything in it. The ReportSightingRequest object too is exactly the same as the ReportSightingRequest in the WCF application.
It almost feels like that the object isn't being serialized. That's the only thing I can think of.
Does anyone have any ideas/suggestions?
Update
I've noticed that i'm actually not sending over the object. Shawn Kendrot's Answer seems to make sense but when I integrate his code, it returns with a Not Found error.
Update
The following code works in a Console App:
var jsonData = "a hard coded JSON string here";
var uri = new Uri("a url goes here", UriKind.Absolute);
var webRequest = (HttpWebRequest)WebRequest.Create(uri);
webRequest.Method = "POST";
webRequest.ContentType = "application/json; charset=utf-8";
webRequest.ContentLength = jsonData.Length;
webRequest.BeginGetRequestStream(ar =>
{
try
{
using (var os = webRequest.EndGetRequestStream(ar))
{
var postData = Encoding.UTF8.GetBytes(jsonData);
os.Write(postData, 0, postData.Length);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
webRequest.BeginGetResponse(
ar2 =>
{
try
{
using (var response = webRequest.EndGetResponse(ar2))
using (var reader = new StreamReader(response.GetResponseStream()))
{
var received = reader.ReadToEnd();
//Console.WriteLine(received);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}, null);
}, null);
Update
I have changed my code in WP8 to match that of Shawn Kendrot's solution. The problem which I am facing here is that I get a Not Found error message:
webRequest.BeginGetRequestStream(ar =>
{
try
{
using (var os = webRequest.EndGetRequestStream(ar))
{
var postData = Encoding.UTF8.GetBytes(jsonData);
os.Write(postData, 0, postData.Length);
}
}
catch (Exception ex)
{
MessageBox.Show("Unsuccessful");
}
webRequest.BeginGetResponse(
ar2 =>
{
try
{
using (var response = webRequest.EndGetResponse(ar2))
using (var reader = new StreamReader(response.GetResponseStream()))
{
var received = reader.ReadToEnd();
}
}
catch (Exception ex)
{
MessageBox.Show("Unsuccessful");
}
}, null);
}, null);
I get a:
{System.UnauthorizedAccessException: Invalid cross-thread access.
at MS.Internal.XcpImports.CheckThread()
at MS.Internal.XcpImports.MessageBox_ShowCore(String messageBoxText, String caption, UInt32 type)
at System.Windows.MessageBox.ShowCore(String messageBoxText, String caption, MessageBoxButton button)
at System.Windows.MessageBox.Show(String messageBoxText)
at Notify.Logic.WebServices.<>c_DisplayClass2.b_1(IAsyncResult ar2)
at System.Net.Browser.ClientHttpWebRequest.<>c_DisplayClass1d.b_1b(Object state2)}
When I try to do `MessageBox.Show(ex.Message);
Update
I have fixed the issue with the MessageBox.Show error message.
The webRequest.Headers object has the following:
{Content-Type: application/json; charset=utf-8;}

Your sightingRequest is null because you are not sending any data. To send data using a WebRequest, you need to use the BeginGetRequestStream method. This method allows you to package the data.
var webRequest= (HttpWebRequest)WebRequest.Create(uri);
webRequest.Method = "POST";
webRequest.ContentType = "application/json";
webRequest.ContentLength = jsonData.Length;
webRequest.BeginGetRequestStream(ar =>
{
try
{
using (Stream os = webRequest.EndGetRequestStream(ar))
{
var postData = Encoding.UTF8.GetBytes(jsonData);
os.Write(postData, 0, postData.Length);
}
}
catch (Exception ex)
{
// Do something, exit out, etc.
}
webRequest.BeginGetResponse(
ar2 =>
{
try
{
using (var response = webRequest.EndGetResponse(ar2))
using (var reader = new StreamReader(response.GetResponseStream()))
{
string received = reader.ReadToEnd();
}
}
catch (Exception ex)
{
// Do something, exit out, etc.
}
}, null);
}, null);

oauth/token returns empty body

I am encountering a problem getting the access_token in client application using oauth.
The returned response has empty body though in API I can see the response is not empty.
tokenresponse = {
"access_token":"[ACCESSTOKENVALUE]",
"token_type":"bearer",
"expires_in":"1200",
"refresh_token":"[REFRESHTOKENVALUE]",
"scope":"[SCOPEVALUE]"
}
The method from API that returns the token http://api.sample.com/OAuth/Token:
public ActionResult Token()
{
OutgoingWebResponse response =
this.AuthorizationServer.HandleTokenRequest(this.Request);
string tokenresponse = string.Format("Token({0})", response!=null?response.Body:""));
return response.AsActionResult();
}
The client method that requests the token is:
public string GetAuthorizationToken(string code)
{
string Url = ServerPath + "OAuth/Token";
string redirect_uri_encode = UrlEncode(ClientPath);
string param = string.Format("code={0}&client_id={1}&client_secret={2}&redirect_uri={3}&grant_type=authorization_code",code, ClientId, ClientSecret, redirect_uri_encode);
HttpWebRequest request = HttpWebRequest.Create(Url) as HttpWebRequest;
string result = null;
request.Method = "POST";
request.KeepAlive = true;
request.ContentType = "application/x-www-form-urlencoded";
request.Timeout = 10000;
request.Headers.Remove(HttpRequestHeader.Cookie);
var bs = Encoding.UTF8.GetBytes(param);
using (Stream reqStream = request.GetRequestStream())
{
reqStream.Write(bs, 0, bs.Length);
}
using (WebResponse response = request.GetResponse())
{
var sr = new StreamReader(response.GetResponseStream());
result = sr.ReadToEnd();
sr.Close();
}
if (!string.IsNullOrEmpty(result))
{
TokenData tokendata = JsonConvert.DeserializeObject<TokenData>(result);
return UpdateAuthorizotionFromToken(tokendata);
}
return null;
}
The result variable is empty.
Please let me know if you have any idea what could cause this. Initially I assumed is because of the cookies so I tried to remove them from request.
Thanks in advance.

Dear just create webclient using following code and you will get json info in tokeninfo.I used it and simply its working perfect.
WebClient client = new WebClient();
string postData = "client_id=" + ""
+ "&client_secret=" + ""
+ "&grant_type=password&username=" + "" //your username
+ "&password=" + "";//your password :)
string soundCloudTokenRes = "https://api.soundcloud.com/oauth2/token";
string tokenInfo = client.UploadString(soundCloudTokenRes, postData);
You can then use substring that contains only token from tokeninfo.
To upload tracks on sound cloud.
private void TestSoundCloudupload()
{
System.Net.ServicePointManager.Expect100Continue = false;
var request = WebRequest.Create("https://api.soundcloud.com/tracks") as HttpWebRequest;
//some default headers
request.Accept = "*/*";
request.Headers.Add("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.3");
request.Headers.Add("Accept-Encoding", "gzip,deflate,sdch");
request.Headers.Add("Accept-Language", "en-US,en;q=0.8,ru;q=0.6");
//file array
var files = new UploadFile[] { new UploadFile(Server.MapPath("Downloads//0.mp3"), "track[asset_data]", "application/octet-stream") };
//other form data
var form = new NameValueCollection();
form.Add("track[title]", "Some title");
form.Add("track[sharing]", "public");
form.Add("oauth_token", "");
form.Add("format", "json");
form.Add("Filename", "0.mp3");
form.Add("Upload", "Submit Query");
try
{
using (var response = HttpUploadHelper.Upload(request, files, form))
{
using (var reader = new StreamReader(response.GetResponseStream()))
{
Response.Write(reader.ReadToEnd());
}
}
}
catch (Exception ex)
{
Response.Write(ex.ToString());
}
}