How to add a custom header to HttpClient()? - c#

I'm trying to add a custom header to the request header of my web application. In my web application im retrieving data from a web api, in this request i want to add a custom header which contains the string sessionID. I'm looking for a general solution so that I dont have to add the same code before every call I make.
My Controller looks like this:
[HttpGet]
public async Task<ActionResult> getCall()
{
string url = "http://localhost:51080/";
string customerApi = "customer/1";
using (var client = new HttpClient())
{
//get logged in userID
HttpContext context = System.Web.HttpContext.Current;
string sessionID = context.Session["userID"].ToString();
//Create request and add headers
client.BaseAddress = new Uri(url);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//Custom header
//Response
HttpResponseMessage response = await client.GetAsync(customerApi);
if (response.IsSuccessStatusCode)
{
string jsondata = await response.Content.ReadAsStringAsync();
return Content(jsondata, "application/json");
}
return Json(1, JsonRequestBehavior.AllowGet);
}
}
Hope anybody can help!
Thanks in advance!

Try this:
client.DefaultRequestHeaders.Add("X-Version","1");

Collection behind DefaultRequestHeaders has Add method which allows you to add whatever header you need:
client.DefaultRequestHeaders.Add("headerName", sesssionID);

Related

How to consume a API and return the content in JSON format?

I'm struggling with the following problem:
I've created a solution with the following projects: 1 MVC front-end and 2 test API's for testing my backend API broker.
In my front-end I call my API broker(which is also an API) which sends requests to my 2 test API's. I'm receiving the response of this request in my API Broker in string format and I'm trying to return this into JSON to my front-end, how do I consume this api and return the response in JSON to my front-end? Look code below:
Front-end calling my API Broker:
[HttpGet]
public async Task<ActionResult> getCall()
{
string url = "http://localhost:54857/";
string operation = "getClients";
using (var client = new HttpClient())
{
//get logged in userID
HttpContext context = System.Web.HttpContext.Current;
string sessionID = context.Session["userID"].ToString();
//Create request and add headers
client.BaseAddress = new Uri(url);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//Custom header
client.DefaultRequestHeaders.Add("loggedInUser", sessionID);
//Response
HttpResponseMessage response = await client.GetAsync(operation);
if (response.IsSuccessStatusCode)
{
string jsondata = await response.Content.ReadAsStringAsync();
return Content(jsondata, "application/json");
}
return Json(1, JsonRequestBehavior.AllowGet);
}
}
My API Broker consuming one of my two test API's:
[System.Web.Http.AcceptVerbs("GET")]
[System.Web.Http.HttpGet]
[System.Web.Http.Route("RedirectApi")]
public void getCall()
{
setVariables();
WebRequest request = WebRequest.Create(apiUrl);
HttpWebResponse response = null;
response = (HttpWebResponse)request.GetResponse();
using (Stream stream = response.GetResponseStream())
{
StreamReader sr = new StreamReader(stream);
var srResult = sr.ReadToEnd();
sr.Close();
//Return JSON object here!
}
}
I'm also worried that my front-end is expecting a ActionResult instead of a JSON object, I hope you I find some suggestions here.
Thanks in advance!
use HttpClient for making the request which allows you to read the content as string. Your API needs to be configured so it will allow JSON responses (default behavior) and then here is an example of making a request and reading it as string which will be in JSON format (if the API returns a JSON body).
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.GetAsync("http://www.contoso.com/");
response.EnsureSuccessStatusCode();
string responseBody = await response.Content.ReadAsStringAsync();
Receiving JSON data back from HTTP request

How to prevent escaping while making a GET request?

I'm trying to consume data in my front-end which calls a API Broker and this API Broker calls my API. In my front-end I'm getting JSON data returned JSON with alot of backslashes in it. How can i prevent this? see code and errors below:
Consuming my API in my front-end:
[HttpGet]
public async Task<ActionResult> getCall()
{
string url = "http://localhost:54857/";
string operation = "getClients";
using (var client = new HttpClient())
{
//get logged in userID
HttpContext context = System.Web.HttpContext.Current;
string sessionID = context.Session["userID"].ToString();
//Create request and add headers
client.BaseAddress = new Uri(url);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//Custom header
client.DefaultRequestHeaders.Add("loggedInUser", sessionID);
//Response
HttpResponseMessage response = await client.GetAsync(operation);
if (response.IsSuccessStatusCode)
{
string jsondata = await response.Content.ReadAsStringAsync();
return Content(jsondata, "application/json");
}
return Json(1, JsonRequestBehavior.AllowGet);
}
}
My Api Broker gets the request and executes this:
As you can see the response content contains alot of backslashes.
This response is going back to my front-end where i receive the following content:
In this response there are even more backslashes added.
I hope someone recognizes this problem and knows a solution.
Thanks in advance!
I fixed it by serializing the string to a JSON object and than deserialize it .

Xamarin Forms Post Request Body

public async static Task<RootUserData> getUSerLoggedIn(string userName, string password)
{
RootUserData rootUserData = new RootUserData();
var url = URlConstants.LOGIN_URL;
using (HttpClient httpClient = new HttpClient())
{
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes($"{userName}:{password}");
httpClient.DefaultRequestHeaders.Add("content-type", "application/json");
httpClient.DefaultRequestHeaders.Add("cache-control", "no-cache");
} ;
}
I am using above code to make one Service call. I have to pass userEmailAddress in body as plain as shown in Postman Picture. Can You Please help me How to achieve this?
No... Its in Plain Text
Set your content mime type to "text/plain":
httpClient.DefaultRequestHeaders.Add("content-type", "text/plain");
And post a string:
var response = await httpClient.PostAsync(url, new StringContent(userName));
Content-Type should not be added like that, It didn't work in my case, and gave a wrong response, instead
Pass content-Type like this -
httpRequest.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/x-www-form-urlencoded");

C# Web API - POST Request doesn't get executed

I am trying to send a POST request from my ASP.NET Core Web API Project but the request is never sent. The method gets executed with no errors but the request never gets sent out from the async method.
My Implementation:
public async void notify(String message)
{
String url = "MY_WEBSERVICE_URL";
var client = new HttpClient();
client.BaseAddress = new Uri(url);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "relativeAddress");
request.Content = new StringContent("application/x-www-form-urlencoded;charset=UTF-8",
Encoding.UTF8, "application/json");
Byte[] byteArray = Encoding.UTF8.GetBytes("{\"text\":\"" + message + "\"}");
request.Content.Headers.ContentLength = byteArray.Length;
await client.SendAsync(request).ContinueWith(responseTask =>
{
Console.WriteLine("Response: {0}", responseTask.Result);
});
}
Is this the proper way of making a POST request from a Core Web API project? Thank you in advance
First of all, there is a dedicated method PostAsync in the HttpClient class ( or even PostAsJsonAsync extension) which you can use to send POST requests without creating HttpRequstMessage manually.
Now about your code - I believe you want to post following JSON string:
{"text":"someMessage"}
You should set this string as a content of StringContent which you are sending:
var json = "{\"text\":\"" + message + "\"}";
request.Content = new StringContent(json, Encoding.UTF8, "application/json");
Currently you are trying to post mediatype string as a value to your API endpoint. Of course it cannot be deserialized into your model.
Note1: StringContent will automatically add Content-Length header with the appropriate value. You should not do that manually.
Note2: Unless this is an event handler, you should not use async void - use async Task instead.
Same task with PostAsJsonAsync usage will look like:
public async Task Notify(string message)
{
var string url = "MY_WEBSERVICE_URL";
var client = new HttpClient();
client.BaseAddress = new Uri(url);
var notification = new Notification { Text = message }; // use some model class
var resonse = await client.PostAsJsonAsync("relativeAddress", notification);
if (response.IsSuccessStatusCode)
{
var content = await response.Content.ReadAsStringAsync();
}
}
In this case, your model will be automatically serialized into JSON, appropriate content will be created and POST request will be sent.
Try Adding [IgnoreAntiforgeryToken] on top of the Post Action like this

How to get and print response from Httpclient.SendAsync call

I'm trying to get a response from a HTTP request but i seem to be unable to. I have tried the following:
public Form1() {
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("someUrl");
string content = "someJsonString";
HttpRequestMessage sendRequest = new HttpRequestMessage(HttpMethod.Post, client.BaseAddress);
sendRequest.Content = new StringContent(content,
Encoding.UTF8,
"application/json");
Send message with:
...
client.SendAsync(sendRequest).ContinueWith(responseTask =>
{
Console.WriteLine("Response: {0}", responseTask.Result);
});
} // end public Form1()
With this code, i get back the status code and some header info, but i do not get back the response itself. I have tried also:
HttpResponseMessage response = await client.SendAsync(sendRequest);
but I'm then told to create a async method like the following to make it work
private async Task<string> send(HttpClient client, HttpRequestMessage msg)
{
HttpResponseMessage response = await client.SendAsync(msg);
string rep = await response.Content.ReadAsStringAsync();
}
Is this the preferred way to send a 'HttpRequest', obtain and print the response? I'm unsure what method is the right one.
here is a way to use HttpClient, and this should read the response of the request, in case the request return status 200, (the request is not BadRequest or NotAuthorized)
string url = 'your url here';
// usually you create on HttpClient per Application (it is the best practice)
HttpClient client = new HttpClient();
using (HttpResponseMessage response = client.GetAsync(url).GetAwaiter().GetResult())
{
using (HttpContent content = response.Content)
{
var json = content.ReadAsStringAsync().GetAwaiter().GetResult();
}
}
and for full details and to see how to use async/await with HttpClient you could read the details of this answer

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