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API POST call from Console Application

How to do the REST API POST Call from the console Application ?
I want to pass the class from the Console application to the REST API. My below code is working if I have to do the GET call but not for the POST. It is hitting the API but in the Parameter it is not passing anything.
API
public class Student
{
public int Id { get; set; }
public string Name { get; set; }
}
public class ValuesController : ApiController
{
// GET api/values
public IEnumerable<string> Get()
{
return new string[] { "value1", "value2" };
}
// GET api/values/5
public string Get(int id)
{
return "value";
}
// POST api/values
//public void Post([FromBody]string value)
//{
//}
public void Post([FromBody]Student value)
{
}
}
Console Application
static async Task CallWebAPIAsync()
{
var student = new Student() { Id = 1, Name = "Steve" };
using (var client = new HttpClient())
{
//Send HTTP requests from here.
client.BaseAddress = new Uri("http://localhost:58847/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage response = await client.PostAsJsonAsync("api/values", student);
if (response.IsSuccessStatusCode)
{
}
else
{
Console.WriteLine("Internal server Error");
}
}
}
The Same is working if I call from fiddler.
User-Agent: Fiddler
Content-Length: 31
Host: localhost:58847
Content-Type: application/json
Request Body:
{
"Id":"1",
"Name":"Rohit"
}

This is working for me.
public async Task CallWebAPIAsync()
{
var student = "{'Id':'1','Name':'Steve'}";
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://localhost:58847/");
var response = await client.PostAsync("api/values", new StringContent(student, Encoding.UTF8, "application/json"));
if (response != null)
{
Console.WriteLine(response.ToString());
}
}

You are not serializing the student object.
You can try to send a StringContent
StringContent sc = new StringContent(Student)
HttpResponseMessage response = await client.PostAsJsonAsync("api/values", sc);
if this doesn't work (a long time I used StringContent).
Use NewtonSoft sterilizer
string output = JsonConvert.SerializeObject(product);
HttpResponseMessage response = await client.PostAsJsonAsync("api/values", output);

To be honest I don't know. It seems like your StringContent did not sterilize it to UTF8 which your restful API is trying to do by default. However, your console application should also do that by default.
The issue seemed to be that the restful API could not bind the byte data and therefor not assign the data to your class Student in the restful API.
What you can try to do is add following code before you make your post to API:
var encoding = System.Text.Encoding.Default;
It will tell you what is your default encoding type. It could be that UTF8 is not the default encoding for some reason.

How to Seriailize an c# object into Json, while using httpClient?

I have a little program which should communicate with "Slack". In an older Version I used "Dictionary<string, string>" and then put them into UrlEncodedContent - which worked fine.
Now I am trying to create a Json-object, using Newtonsoft's Nuget-package and (in my opinion) formatting my object the way they say on their website.
Problem is, when I try to make a simple request, my program just runs to one specific line in the code(var response = await _httpClient.SendAsync(request);) and then it just ends. It doesn't throw an exception or display any kind of message, it simply ends on this line. I went through my code step by step while debugging, that's how I know it ends on exactly this line. And I just don't know why!
Now my code:
First, my object...
namespace BPS.Slack
{
public class JsonObject
{
//generally needed parameters
[JsonProperty("ok")]
public bool ok { get; set; }
[JsonProperty("error")]
public string error { get; set; }
[JsonProperty("channel")]
public string channel { get; set; }
[JsonProperty("token")]
private string token = "xoxp-MyToken";
[JsonProperty("as_user")]
public bool as_user = false;
[JsonProperty("username")]
public string username { get;set; }
//--------------------------------
//only needed for textmessages
[JsonProperty("text")]
public string text { get; set; }
//--------------------------------
//for posting messages with data attached
[JsonProperty("initial_comment")]
public string initial_comment { get; set; }
[JsonProperty("file")]
public string file { get; set; }
[JsonProperty("channels")]
public string channels { get; set; }
//--------------------------------
//for getting the latest message from a channel
[JsonProperty("count")]
public string count = "1";
[JsonProperty("unreads")]
public bool unreads = true;
}
}
now the client:
namespace BPS.Slack
{
public class BpsHttpClient
{
private readonly HttpClient _httpClient = new HttpClient { };
public Uri UriMethod { get; set; }
public BpsHttpClient(string webhookUrl)
{
UriMethod = new Uri(webhookUrl);
}
public async Task<HttpResponseMessage> UploadFileAsync(MultipartFormDataContent requestContent)
{
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, UriMethod);
request.Content = requestContent;
var response = await _httpClient.SendAsync(request);
return response;
}
}
}
and the main
namespace TestArea
{
class MainArea
{
public static void Main( string[] args)
{
try
{
Task.WhenAll(SendMessage());
}
catch(Exception ass)
{
Console.WriteLine(ass);
Console.ReadKey();
}
}
private static async Task SendMessage()
{
var client = new BpsHttpClient("https://slack.com/api/im.history");
JsonObject JO = new JsonObject();
JO.channel = "DCW21NBHD";
var Json = JsonConvert.SerializeObject(JO);
var StringJson = new StringContent(Json, Encoding.UTF8);
MultipartFormDataContent content = new MultipartFormDataContent();
content.Add(StringJson);
var Response = await client.UploadFileAsync(content);
string AnswerContent = await Response.Content.ReadAsStringAsync();
Console.WriteLine(AnswerContent);
Console.ReadKey();
}
}
}
I had the same problem in my older version, BUT only as I wanted to DEserialize an answer I got from Slack. It had to do with my object I tried do deserialize the answer into. But this time I can not figure out what's wrong. But, as I said, I do not have any experience with using serialized objects as Json-property to send requests... anyone has an idea what is wrong with my code?
EDIT: This problem is kinda solved. But there is a follow up problem.
Okay, I found out that the reason for the abprubt termination was the
Task.WhenAll(SendMessage());
it should be
Task.WaitAll(SendMessage()); Why??? Somebody said I should use WhenAll, but obviously it doesn't work properly in this case...
Now I get a response from Slack, but now a different problem has arisen. When I use this method:
public async Task<HttpResponseMessage> UploadFileAsync(MultipartFormDataContent requestContent)
{
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, UriMethod);
request.Content = requestContent;
var response = await _httpClient.SendAsync(request);
return response;
}
I allways get the answer:
{"ok":false,"error":"invalid_form_data"}
so I tried to explicitly tell it the 'mediaType', I tried "application/json" and others, but with all of them I get the same error. Here is the full method that calls the upper mehtod:
private static async Task SendMessage()
{
var client = new BpsHttpClient("https://slack.com/api/chat.postMessage");
JsonObject JO = new JsonObject();
JO.channel = "DCW21NBHD";
JO.text = "This is so much fun :D !";
var Json = JsonConvert.SerializeObject(JO, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
var StringJson = new StringContent(Json, Encoding.UTF8, "application/json");
var requestContent = new MultipartFormDataContent();
requestContent.Add(StringJson);
var Response = await client.UploadFileAsync(requestContent);
string AnswerContent = await Response.Content.ReadAsStringAsync();
}
When I use this method:
public async Task<HttpResponseMessage> SendMessageAsync(FormUrlEncodedContent content)
{
var response = await _httpClient.PostAsync(UriMethod, content);
return response;
}
so bascially I am passing "FormUrlEncodedContent" instead of "MultipartFormDataContent" in this, and then I get the response I want and can work wiht it. BUT this i of little use to me since I have to use "MultipartFormDataContent" to be able to send files with my requests.
Anyone have an idea what is failing here? Why does it not like the one content-type but the other one? I'd be gratefull for tipps and ideas!

You are serializing your object to Json and then adding it to a Multipart body, that's quite strange. Unless you're uploading binary data (eg Files), there is no need to use MultipartFormDataContent.
You are can directly post your JsonObject serialized as JSON:
public async Task<HttpResponseMessage> PostJsonAsync(StringContent content)
{
var response = await client.PostAsync(url, content);
return response;
}
var client = new BpsHttpClient("https://slack.com/api/im.history");
JsonObject JO = new JsonObject();
JO.channel = "DCW21NBHD";
var Json = JsonConvert.SerializeObject(JO);
var StringJson = new StringContent(Json, Encoding.UTF8);
var Response = await client.PostJsonAsync(content);
Also this is should be POST on the UploadFileAsync function.
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, UriMethod);

so I figured out that in the Main() the problem was this:
Task.WhenAll(SendMessage());
I should instead use:
Task.WaitAll(SendMessage());
Anyone who has more knowledge on this, please elaborate why!

C# Api controller not receiving json parameter

I am trying to create a basic test web api, and use a standard controller to test call it.
When I run it, by putting
http://localhost:55144/home/testapi
it'll run the catcher function and completely ignore the parameter.
Then, the catcher will happily return a value, which can be seen in the calling code.
I have tried various combinations of putting [FromBody], changing the type of the parameter in TestApiMethod, and seeing if making a list or array makes any difference.
I've noticed a couple of weird things:
- I'm not using the parameter in the code of TestApiMethod, but Visual Studio is not giving me an unused variable warning.
- If I make the type of the parameter testString a string or even an int, the code below will route to the catcher. If I make it some variation of a model or a Jobject, it will not. It gets as far as running
HttpResponseMessage response = await client.PostAsJsonAsync("api/activity", sendData);
then just returns to the web page.
Here's the code:
Models
public class testStringModel
{
public string testString { get; set; }
}
public class apiResponse
{
public string response { get; set; }
}
Home controller calling Api:
public void TestApi()
{
Task myTask = testApiCall();
}
private async Task<string> testApiCall()
{
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://localhost:55144");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
testStringModel data = new testStringModel { testString = "cheese" };
string jsonData = JsonConvert.SerializeObject(data);
var sendData = new StringContent(jsonData, Encoding.UTF8, "application/json");
//var sendData = new Dictionary<string, string>
//{
// {"testString", "cheese"}
//};
HttpResponseMessage response = await client.PostAsJsonAsync("api/activity", sendData);
string responseBodyAsText = await response.Content.ReadAsStringAsync();
dynamic stuff = JObject.Parse(responseBodyAsText);
string finalResponse = stuff.response;
return finalResponse;
}
}
The api:
namespace ApplicationActivity
{
public class ActivityController : ApiController
{
[System.Web.Http.HttpPost]
public HttpResponseMessage Catcher()
{
apiResponse apiResponseObject = new apiResponse();
apiResponseObject.response = "You have somehow wound up in the catcher";
string json = JsonConvert.SerializeObject(apiResponseObject);
HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK, "value");
response.Content = new StringContent(json, Encoding.Unicode, "application/json");
response.Headers.CacheControl = new CacheControlHeaderValue()
{
MaxAge = TimeSpan.FromMinutes(20)
};
return response;
}
[System.Web.Http.HttpPost]
public HttpResponseMessage TestApiMethod(string testString)
{
apiResponse apiResponseObject = new apiResponse();
apiResponseObject.response = "OK from test";
string json = JsonConvert.SerializeObject(apiResponseObject);
HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK, "value");
response.Content = new StringContent(json, Encoding.Unicode, "application/json");
response.Headers.CacheControl = new CacheControlHeaderValue()
{
MaxAge = TimeSpan.FromMinutes(20)
};
return response;
}
}
}
Please will you tell me what I'm doing wrong with my code, how to fix it and what is happening when the code doesn't get to the catcher?
Thanks.

It turns out that I was using an older version of visual studio and as a result the whole thing got really confused with whether is was running .net core or not.
Upgrading to the latest and making sure the latest .net core is installed solved most of my troubles

Retrieving the response from Rest API

I am working on creating an API that call the other third party API. The third party API is an REST API and returns response in the JSON format when I call it in the web browser
[{"Acc":"IT","Cnt":"023","Year":"16"}]
I am trying to get the same response when I call the third party API from my API.
public IHttpActionResult Get(string acctID)
{
using (var client_EndPoint= new HttpClient())
{
Uri uri_EndPoint = new Uri(BaseURL_EndPoint);
client_EndPoint.BaseAddress = uri;
client_EndPoint.DefaultRequestHeaders.Accept.Clear();
client_EndPoint.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
string EndPoint_URL = BaseURL_EndPoint+"api/NameCreation?Account="+acctID;
var response_EndPoint = client_EndPoint.GetAsync(EndPoint_URL).Result;
string responseString = response_EndPoint.Content.ReadAsStringAsync().Result;
return Ok(responseString);
}
}
What I have been doing is getting the response from the third party API in a string. But I am checking if there is a way I can get in the JSON format so I can return them directly. The return type of the get method is IHttpActionResult. If I am returning as string the response looks like
"[{\"Acc\":\"adm\",\"Cnt\":\"001\",\"Year\":\"16\"}]"
Any help is greatly appreciated.

Create a model to hold rest api data
public class Model {
public string Acc { get; set; }
public string Cnt { get; set; }
public string Year { get; set; }
}
Deserialize it from api
var response_EndPoint = await client_EndPoint.GetAsync(EndPoint_URL);
var models = await response_EndPoint.Content.ReadAsAsync<Model[]>();
And then return that
return Ok(models);
Full example
public async Task<IHttpActionResult> Get(string LabName) {
using (var client_EndPoint = new HttpClient()) {
//...other code removed for brevity
var response_EndPoint = await client_EndPoint.GetAsync(EndPoint_URL);
var models = await response_EndPoint.Content.ReadAsAsync<Model[]>();
return Ok(models);
}
}

you can use Newtonsoft.Json ,Just add it from nuget and add this config to webapiconfig:
var json = config.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling =
Newtonsoft.Json.PreserveReferencesHandling.Objects;
config.Formatters.Remove(config.Formatters.XmlFormatter);
then use
return Json(responseString)

Object null in WebApi method after PostAsJsonAsync

I am posting an object to a WebApi method. I'm using PostAsJsonAsync to do this.
public async Task<HttpResponseMessage> PostAsync(string token, ServiceCall call)
{
var client = new HttpClient();
client.SetBearerToken(token);
var response = await client.PostAsJsonAsync(Uri + "id/nestedcall", call);
return response;
}
The object call that I'm passing is not null when I post it.
[HttpPost]
[Route("id/nestedcall")]
public async Task<IHttpActionResult> NestedCall([FromBody]ServiceCall call)
{
// call is null here
}
However it is null in my API method. I can't seem to work out why as all of the examples I've followed use this format.
Why isn't the call object being picked up by the web api?
Edit
Here is the ServiceCall object. It is in a separate class library and a reference is included in both the web application and the API.
public class ServiceCall
{
public ServiceCall(Service service, string grantType)
{
ClientId = service.Id;
ClientSecret = service.Secret;
Uri = service.Uri;
Scope = service.Scope;
GrantType = grantType;
}
public ServiceCall(string clientid, string clientsecret, string uri, string scope, string grantType)
{
ClientId = clientid;
ClientSecret = clientsecret;
Uri = uri;
Scope = scope;
GrantType = grantType;
}
public string ClientId { get; set; }
public string ClientSecret { get; set; }
public string Uri { get; set; }
public string Scope { get; set; }
public string GrantType { get; set; }
}

I have seen Object null in WebApi method after PostAsJsonAsync due to serialization.
Better to use PostAsync like below :
var obj = new MyClass()
{
MyProperty = 11
};
using (var client = new HttpClient())
{
string inputJson = Newtonsoft.Json.JsonConvert.SerializeObject(obj);
HttpContent inputContent = new StringContent(inputJson, Encoding.UTF8, "application/json");
HttpResponseMessage response1 = client.PostAsync("http://localhost:60909/api/home/Test", inputContent).Result;
if (response1.IsSuccessStatusCode)
{
}
}

Using Prefix Stackify I was able to diagnose that the serialiser was throwing an exception:
Newtonsoft.Json.JsonSerializationException: Unable to find a constructor to use for type Core.Models.ServiceCall. A class should either have a default constructor, one constructor with arguments or a constructor marked with the JsonConstructor attribute. Path 'ClientId', line 1, position 12.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateNewObject
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize
However, very helpfully, rather than tell me that an exception occurred the controller simply gave me a null object.
As hinted by the exception the solution is to add a default constructor (or at least one the serialiser can understand).
public ServiceCall()
{
}

looks like the JSON serialization may be failing. BTW, remove that [FromBody] and try without it like below. PostAsJsonAsync method serializes the ServiceCall object to JSON and then sends the JSON payload in a POST request.
public async Task<IHttpActionResult> NestedCall(ServiceCall call)
{
// your code
}

I run into exactly the same problem and had to do this to solve it:
using (var client = new HttpClient())
{
client.SetBearerToken(token);
var content = new StringContent(JsonConvert.SerializeObject(call), Encoding.UTF8, "application/json");
var response = await client.PostAsJsonAsync(Uri + "id/nestedcall", content);
return response;
}