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c# HttpClient PostAsync with async and await not working

I am running into a deadlock situation when trying to post to WebApi 2 from WebApi 1 using HttpClient PostAsync and using async and await.
Below is WebAPI 1:
public HttpResponseMessage Get([FromUri]int oid)
{
var orderdetails = _orderServices.GetOrderDetails(oid);
var xml = new XmlMediaTypeFormatter();
xml.UseXmlSerializer = true;
string orderdetailsser = Serialize(xml, orderdetails);
var result = PostXml(orderdetailsser);
return Request.CreateResponse(HttpStatusCode.OK);
}
public static async Task<HttpResponseMessage> PostXml(string str)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri("http://localhost:58285/");
var content = new StringContent(str);
var response = await client.PostAsync("api/default/ReceiveXml", content).ConfigureAwait(false);
return response;
}
}
And WebApi2:
[System.Web.Http.HttpPost]
public HttpResponseMessage ReceiveXml(HttpRequestMessage request)
{
var xmlDoc = new XmlDocument();
xmlDoc.Load(request.Content.ReadAsStreamAsync().Result);
xmlDoc.Save(#"C:\xmlfiles\xml2.xml");
XmlSerializer deserializer = new XmlSerializer(typeof(OrderInfoModel));
TextReader reader = new StreamReader(#"C:\xmlfiles\xml2.xml");
object obj = deserializer.Deserialize(reader);
OrderInfoModel orderdetails = (OrderInfoModel)obj;
reader.Close();
var patient_id = _patientServices.ProcessPatient(orderdetails.Patient, orderdetails.OrderInfo);
var orderid = _orderServices.ProcessOrder(orderdetails.Patient, orderdetails.OrderInfo, patient_id);
if (orderdetails.OrderNotes != null && orderdetails.OrderNotes.Count() > 0)
{
var success = _orderServices.ProcessOrderNotes(orderid, orderdetails.OrderNotes);
}
var prvid = _orderServices.ProcessOrderProvider(orderid, orderdetails.ReferringProvider);
var shpngid = _orderServices.ProcessOrderShipping(orderid, orderdetails.ShippingInfo);
var payerid = _orderServices.ProcessOrderPayer(orderid, orderdetails.Insurances);
return Request.CreateResponse(HttpStatusCode.OK, orderid);
}
I am not getting any response back to WebAPI 1 from WebAPI 2. I have gone through several articles online about deadlock situation. However, I am unable to resolve the deadlock in my case. What am I doing wrong here? Am I using async and await properly?

To build off my comment above, modify your code so that you are not blocking on an async operation. Additionally _orderServices.GetOrderDetails(oid); sounds like a method that hits a database and as such should be await _orderServices.GetOrderDetailsAsync(oid); wherein you use the whatever async api is available for your database access.
[HttpGet()]
public async Task<HttpResponseMessage> Get([FromUri]int oid) {
var orderdetails = _orderServices.GetOrderDetails(oid);
var xml = new XmlMediaTypeFormatter();
xml.UseXmlSerializer = true;
string orderdetailsser = Serialize(xml, orderdetails);
var result = await PostXml(orderdetailsser);
return Request.CreateResponse(HttpStatusCode.OK);
}
public static async Task<HttpResponseMessage> PostXml(string str) {
using(var client = new HttpClient()) {
client.BaseAddress = new Uri("http://localhost:58285/");
var content = new StringContent(str);
var response = await client.PostAsync("api/default/ReceiveXml", content).ConfigureAwait(false);
return response;
}
}
[HttpPost()]
public async Task<HttpResponseMessage> ReceiveXml(HttpRequestMessage request) {
var xmlDoc = new XmlDocument();
xmlDoc.Load(await request.Content.ReadAsStreamAsync());
xmlDoc.Save(#"C:\xmlfiles\xml2.xml");
XmlSerializer deserializer = new XmlSerializer(typeof(OrderInfoModel));
TextReader reader = new StreamReader(#"C:\xmlfiles\xml2.xml");
object obj = deserializer.Deserialize(reader);
OrderInfoModel orderdetails = (OrderInfoModel)obj;
reader.Close();
var patient_id = _patientServices.ProcessPatient(orderdetails.Patient, orderdetails.OrderInfo);
var orderid = _orderServices.ProcessOrder(orderdetails.Patient, orderdetails.OrderInfo, patient_id);
if(orderdetails.OrderNotes != null && orderdetails.OrderNotes.Count() > 0) {
var success = _orderServices.ProcessOrderNotes(orderid, orderdetails.OrderNotes);
}
var prvid = _orderServices.ProcessOrderProvider(orderid, orderdetails.ReferringProvider);
var shpngid = _orderServices.ProcessOrderShipping(orderid, orderdetails.ShippingInfo);
var payerid = _orderServices.ProcessOrderPayer(orderid, orderdetails.Insurances);
return Request.CreateResponse(HttpStatusCode.OK, orderid);
}
Resources
Don't Block on Async Code
Avoid Async Void

ASP.NET Api Client

I'm learning how to create WEB-API client
I've created some simple API:
[HttpGet]
public IHttpActionResult GetInfo()
{
return Ok("Its working!");
}
[HttpPost]
public IHttpActionResult PostInfo(ClientDataDto dto)
{
try
{
someMethod(dto.IdKlienta, dto.Haslo, dto.IdZgloszenia, dto.HardwareInfo, dto.SoftwareInfo);
return Ok("sent");
}
catch
{
return BadRequest();
}
}
For now I just trying to call GET method.
When I use Fiddler with addr
localhost:someport/api/Client2
its working
but when i try to do it by client, which code is below:
private static HttpClient client = new HttpClient();
static void Main(string[] args)
{
#region TESTONLY
var debug = new XMLData();
string HardwareInfoXML = debug.HardwareXML;
string SoftInfoXML = debug.SoftwareXML;
int id_zgloszenia = 20;
int idKlienta = 25;
//haslo = "202cb962ac59075b964b07152d234b70";
#endregion
var data = new ClientDataDto() { HardwareInfo = HardwareInfoXML, SoftwareInfo = SoftInfoXML, IdKlienta = idKlienta, IdZgloszenia = id_zgloszenia };
RunAsync(data);
}
private static async Task RunAsync(ClientDataDto data)
{
var stringContent = new StringContent(JsonConvert.SerializeObject(data), Encoding.UTF8, "application/json");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.BaseAddress = new Uri(#"http://localhost:7774/api/client2/");
var url = new Uri(#"http://localhost:7774/api/client2/");
var res1 = await client.GetAsync(url);
var res = await client.PostAsync(url, stringContent);
res.EnsureSuccessStatusCode();
}
Application closing without any info at
var res1 = await client.GetAsync(url);
I have checked to see all exceptions in Debug exception Windows, but it is just closing after trying call GetAsync
PostASync doesn't work too.
What is wrong here?

i'm really sorry that i've posted simpe problem.
sulotion is to add .Wait() on RunAsync(data);
RunAsync(data).Wait();

System.Net.Http.HttpClient in [Universal Windows Platform] not working properly

I wrote simple method for getting data from (online) REST Service:
public async Task<Object> GetTask()
{
try
{
using (HttpClient client = new HttpClient())
{
client.BaseAddress = new Uri("http://111.111.111.111:8080/");
HttpResponseMessage result = await client.GetAsync("ABC/CDE/getsomeinfo");
if (result.IsSuccessStatusCode)
{
//Deserialize
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Error" + ex);
}
return null;
}
Whenever i run this on UWP i'm getting catch exception:
The text associated with this error code could not be found.
A connection with the server could not be established
HResult 2147012867
Im trying to connect my client with restapi in internal network. In forms same code is working properly.

Try this
HttpResponseMessage response;
public async Task<string> webserviceResponse(string HttpMethod)
{
// check internet connection is available or not
if (NetworkInterface.GetIsNetworkAvailable() == true)
{
// CancellationTokenSource cts = new CancellationTokenSource(2000); // 2 seconds
HttpClient client = new HttpClient();
MultipartFormDataContent mfdc = new MultipartFormDataContent();
mfdc.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data");
string GenrateUrl = "your url";
if (HttpMethod == "POST")
{
response = await client.PostAsync(GenrateUrl, mfdc);
}
else if (HttpMethod == "PUT")
{
response = await client.PutAsync(GenrateUrl, mfdc);
}
else if (HttpMethod == "GET")
{
response = await client.GetAsync(GenrateUrl);
}
var respon = await response.Content.ReadAsStringAsync();
string convert_response = respon.ToString();
return convert_response;
}
else
{
return "0";
}
}

C# Xamarin Android Rest call in PCL error "Unexpected character encountered while parsing value: S. Path '', line 0, position 0."

I have used SO to help with several issues in the past. However, I cannot find a solution to something I have been struggling with for 2 days now.
I am a noob, please be kind :)
I have an app that I created using Xamarin Studio, targeted for Android. It is a basic GET request from a Rest Api. It was working perfectly until I realized I was not helping myself when it came time to create the same app in IOS and Windows. Once I changed my project to utilize a PCL I started getting errors, primarily around my RestClient class (originally got from http://www.codeproject.com/Tips/497123/How-to-make-REST-requests-with-Csharp)
From my droid app class:
var apiUser = GetString(Resource.String.apiUser);
var apiPass = GetString(Resource.String.apiPass);
//Get token from API
string token = authenticate(apiUser,apiPass);
public static string authenticate(string apiUser, string apiPass)
{
Authentication Auth = new Authentication ();
try
{
// set json by passing AuthenticationUrl as endpoint, returns json data
var o = JObject.Parse(EntryRepository.getJson(PJTApiUrls.getAuthenticationUrl(apiUser,apiPass)));
Auth.Token = (string)o["Token"];
return Auth.Token;
}
catch (Exception e)
{
// Couldn't do stuff. Log the exception.
// TODO possible timeout, try again, if fails again then return error message
if (e.Message.Contains("400") || e.Message.Contains("401"))
{
string error = string.Format("Invalid credentials, please try again");
return error;
} else {
string error = string.Format ("An error occurred: \r\n{0}", e.Message);
return error;
}
}
}
getAuthenticationUrl gets the api URL.
Here is getJson (in PCL):
public static string getJson(string endpoint)
{
string apiurl = endpoint;
var client = new _RestClient();
client.EndPoint = apiurl;
client.ContentType = "application/json";
client.Method = HttpVerb.GET;
//client.Method = HttpVerb.POST;
client.PostData = "";
//client.PostData = "{postData: value}";
//client.PostData = "{'someValueToPost': 'The Value being Posted'}";
var json = client._MakeRequestAsync();
// to append parameters, pass them into make request:
//var json = client.MakeRequest("?param=0");
return json.ToString();
}
And for the _RestClient class (in PCL):
public async Task<string> _MakeRequestAsync()
{
try {
var request = _MakeRequestAsync ("");
return await request;
}
catch (Exception e){
return e.Message;
}
}
public async Task<string> _MakeRequestAsync(string parameters)
{
var uri = new Uri(EndPoint + parameters);
var request = WebRequest.Create(uri) as HttpWebRequest;
using (var response = await request.GetResponseAsync () as HttpWebResponse) {
var responseValue = string.Empty;
if (response.StatusCode != HttpStatusCode.OK) {
var message = String.Format ("Request failed. Received HTTP {0}", response.StatusCode);
throw new Exception (message);
}
// grab the response
using (var responseStream = await Task.Factory.FromAsync<Stream>(request.BeginGetRequestStream, request.EndGetRequestStream, null)) {
//using (var responseStream = response.GetResponseStream ()) {
if (responseStream != null)
using (var reader = new StreamReader (responseStream)) {
responseValue = reader.ReadToEnd ();
}
}
return responseValue;
}
}
responseValue is returning null
return await request is saying "Status = Waiting for activation"
I have also had the error: "Unexpected character encountered while parsing value: S. Path '', line 0, position 0."
But this works if the RestClient class is within Droid (Instead of the shared PCL) and contains the following:
public string MakeRequest ()
{
return MakeRequest ("");
}
public string MakeRequest (string parameters)
{
var request = (HttpWebRequest)WebRequest.Create (EndPoint + parameters);
request.Method = Method.ToString ();
request.ContentLength = 0;
request.ContentType = ContentType;
if (!string.IsNullOrEmpty (PostData) && Method == HttpVerb.POST) {
var bytes = Encoding.GetEncoding ("iso-8859-1").GetBytes (PostData);
request.ContentLength = bytes.Length;
using (var writeStream = request.GetRequestStream ()) {
writeStream.Write (bytes, 0, bytes.Length);
}
}
using (var response = (HttpWebResponse)request.GetResponse ()) {
var responseValue = string.Empty;
if (response.StatusCode != HttpStatusCode.OK) {
var message = String.Format ("Request failed. Received HTTP {0}", response.StatusCode);
throw new ApplicationException (message);
}
// grab the response
using (var responseStream = response.GetResponseStream ()) {
if (responseStream != null)
using (var reader = new StreamReader (responseStream)) {
responseValue = reader.ReadToEnd ();
}
}
return responseValue;
}
}
I cannot figure this out, any help/guidance is appreciated. Let me know if I can clarify anything.
***** UPDATE ***** Thanks to #milen-pavlov help thus far, here is where I am currently at:
in Android project:
var apiUser = GetString(Resource.String.apiUser);
var apiPass = GetString(Resource.String.apiPass);
//Get token from API
var token = await authenticate(apiUser,apiPass);
lblOutput.Text = token;
calls (also in Android project):
public static async Task<string> authenticate(string apiUser, string apiPass)
{
Authentication Auth = new Authentication ();
try
{
// set json by passing AuthenticationUrl as endpoint, returns json data
var o = JObject.Parse(await EntryRepository.getJson(PJTApiUrls.getAuthenticationUrl(apiUser,apiPass)));
Auth.Token = (string)o["Token"];
return Auth.Token;
}
catch (Exception e)
{
if (e.Message.Contains("400") || e.Message.Contains("401"))
{
string error = string.Format("Invalid credentials, please try again");
return error;
} else {
string error = string.Format ("An error occurred: \r\n{0}", e.Message);
return error;
}
}
}
Calls json class in PCL project:
public static async Task<string> getJson(string endpoint)
{
string apiurl = endpoint;
var client = new _RestClient();
client.EndPoint = apiurl;
client.ContentType = "application/json";
client.Method = HttpVerb.GET;
client.PostData = "";
var json = await client._MakeRequestAsync();
return json;
}
which then calls restclient class in PCL project:
public async Task<string> _MakeRequestAsync()
{
var request = _MakeRequestAsync ("");
return await request;
}
public async Task<string> _MakeRequestAsync(string parameters)
{
var uri = new Uri(EndPoint + parameters);
using (var client = new HttpClient())
{
var response = await client.GetAsync(uri);
return await response.Content.ReadAsAsync<string>();
};
}
End result/error:
Any guidance is appreciated!

Can you use HttpClient instead?
Sample Get request will look similar to this:
public async Task<string> _MakeRequestAsync(string parameters)
{
var uri = new Uri(EndPoint + parameters);
using (var client = new HttpClient())
{
var response = await client.GetAsync(uri);
return await result.Content.ReadAsStringAsync();
};
}

GetData from server Windows 8

I have next function:
private void getAllData()
{
HttpWebRequest request = HttpWebRequest.CreateHttp("http://webservice.com/wfwe");
request.BeginGetResponse(new AsyncCallback(GetResponsetStreamCallback), request);
}
void GetResponsetStreamCallback(IAsyncResult callbackResult)
{
HttpWebRequest request = (HttpWebRequest)callbackResult.AsyncState;
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(callbackResult);
using (StreamReader httpWebStreamReader = new StreamReader(response.GetResponseStream()))
{
string result = httpWebStreamReader.ReadToEnd();
GetApplications(result);
}
}
And i fill in stack panels:
private void GetApplications(string result)
{
var ApplicationsList = JsonConvert.DeserializeObject<List<Applications>>(result);
foreach (Applications A in ApplicationsList)
{
foreach (ApplicationRelation SCA in A.ApplicationRelations)
{
if (SCA.ApplicationSubcategory != null)
{
#region Fill Customer Research Stack
if (SCA.ApplicationSubcategory.subcategoryName == "Customer Research")
{
if (TestStack.Children.Count == 0)
{
ApplicationTile AT = FillDataForApplicationTile(SCA);
AT.Margin = new Thickness(5, 0, 5, 0);
TestStack.Children.Add(AT);
}
}
#endregion
}
}
}
}
And code fails at:
if (TestStack.Children.Count == 0)
Error: The application called an interface that was marshalled for a different thread. (Exception from HRESULT: 0x8001010E (RPC_E_WRONG_THREAD))
How can i rewrite my Request from void to string, so i could do something like this:
GetApplications(await getAllData())
EDIT 2 for dcastro:
EDIT 3:
Thanks it works, but i was looking for something like this:
//Modified your code:
GetApplications(getAllData2().Result);
private async Task<string> getAllData2()
{
string uri = "http://webservice.com/wfe";
var client = new HttpClient();
HttpResponseMessage response = await client.GetAsync(uri);
var result = await response.Content.ReadAsStringAsync();
return result.ToString();
}
But somehow my construction doesn't enter GetApplication function...

Instead of using AsyncCallback (which I'm pretty sure is running GetResponsetStreamCallback in a non-UI thread), try fetching your data like this:
private async void getAllData()
string uri = "http://webservice.com/wfwe";
var client = new HttpClient();
HttpResponseMessage response = await client.GetAsync(uri);
string body = await response.Content.ReadAsStringAsync();
GetApplications(body);
}
This will call your webservice asynchronously (at line await Client.sendMessageAsync(msg);), and return to the original UI thread when the response is received. This way, you can update UI elements, like your TestStack.
Edit fixed bug

Try this.
private async Task<string> getAllData()
{
string Result = "";
var http = new HttpClient();
var response = await http.GetAsync("http://webservice.com/wfwe"); // I am considering this URL gives me JSON
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
Result = await response.Content.ReadAsStringAsync(); // You will get JSON here
}
else
{
Result = response.StatusCode.ToString(); // Error while accesing the web service.
}
return Result;
}
private async Task GetApplications(string result)
{
var ApplicationsList = JsonConvert.DeserializeObject<List<Applications>>(result);
foreach (Applications A in ApplicationsList)
{
foreach (ApplicationRelation SCA in A.ApplicationRelations)
{
if (SCA.ApplicationSubcategory != null)
{
#region Fill Customer Research Stack
if (SCA.ApplicationSubcategory.subcategoryName == "Customer Research")
{
if (TestStack.Children.Count == 0)
{
// This will update your UI using UI thread
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, async () =>
{
ApplicationTile AT = FillDataForApplicationTile(SCA);
AT.Margin = new Thickness(5, 0, 5, 0);
TestStack.Children.Add(AT);
});
}
}
#endregion
}
}
}
}