Getting Invalid Content Type doing a Delete httpclient call. What am I doing wrong? - c#

When I try to do the code below, it just results in Invalid Content Type (with error number 612).
I'm trying to delete a lead id from a static list. I can add lead ids or get the static list leads fine.
The post and get calls I make are working fine, although the post calls I make seem to require the data right on the url string (as in $"{endpointURL}/rest/v1/lists/{listID}/leads.json?id={leadID}"; If I include the id as a json object, it fails too. This might be a clue to what I'm doing wrong with the delete call.
string url = $"{endpointURL}/rest/v1/lists/{listID}/leads.json?id={leadID}";
HttpClient client = new HttpClient();
client.BaseAddress = new Uri(url);
client.DefaultRequestHeaders.Authorization = new
AuthenticationHeaderValue("Bearer", _access_token);
HttpResponseMessage response = await client.DeleteAsync(url);
The response here always results in Invalid Content Type.
If I add this line before I do the deleteasync call, it gives me a different error before it even hits the deleteAsync call.
client.DefaultRequestHeaders.Add("Content-Type", "application/json");
Error is "Misused header name. Make sure request headers are used with HttpRequestMessage, response headers with HttpResponseMessage, and content headers with HttpContent objects."


Try using HttpRequestMessage in your code like this
string url = $"{endpointURL}/rest/";
HttpClient client = new HttpClient
{
BaseAddress = new Uri(url)
};
//I'm assuming you have leadID as an int parameter in the method signature
Dictionary<string, int> jsonValues = new Dictionary<string, int>();
jsonValues.Add("id", leadID);
//create an instance of an HttpRequestMessage() and pass in the api end route and HttpMethod
//along with the headers
HttpRequestMessage request = new HttpRequestMessage
(HttpMethod.Delete, $"v1/lists/{listID}") //<--I had to remove the leads.json part of the route... instead I'm going to take a leap of faith and hit this end point with the HttpMethod Delete and pass in a Id key value pair and encode it as application/json
{
Content = new StringContent(new JavaScriptSerializer().Serialize(jsonValues), Encoding.UTF8, "application/json")
};
request.Headers.Add("Bearer", _access_token);
//since we've already told the request what type of httpmethod we're using
//(in this case: HttpDelete)
//we could just use SendAsync and pass in the request as the argument
HttpResponseMessage response = await client.SendAsync(request);


The solution turned out to be a combination of a couple of suggestions.
HttpClient client = new HttpClient();
client.BaseAddress = new Uri(url);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Delete, data);
// The key part was the line below
request.Content = new StringContent(string.Empty, Encoding.UTF8, "application/json");
if (!string.IsNullOrEmpty(_access_token))
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _access_token);
}
HttpResponseMessage response = await client.SendAsync(request);
This worked for me.

Related

GET Request return 400 bad response

It's a generic question, but I need help with my specific case.
I have a simple GET endpoint (see image) which I've tested with Postman and it works
It takes two id tokens in the header and thats it.
I've put breakpoints in the code and copied the exact instance of the ids into Postman and the request works, but executing from code, I get a 400 response
using (HttpClient client = new HttpClient())
{
var request = new HttpRequestMessage()
{
RequestUri = new Uri("https://*******.execute-api.ap-southeast-2.amazonaws.com/dev/uploads/image.jpg"),
Method = HttpMethod.Get,
};
var idToken = Application.Current.Properties["id_token"].ToString();
var accessToken = Application.Current.Properties["access_token"].ToString();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
request.Headers.Add("Id-Token", idToken);
request.Headers.Add("Access-Token", accessToken);
var response = await client.SendAsync(request);
}
I've tried with and without the content-type header and makes no difference. Also doesn't matter if it's present in Postman
This is a Xamarin project which is where Application.Current.Properties comes from. I'm utilising other endpoints in the application are there are no issues with accessing the tokens like this.

C# API Beginner

I have the following code as a start to create a API Call to https://jsonplaceholder.typicode.com/posts/. I want to practice making the call, receive a JSON response and then..do stuff.
How can I finish this off to get a response so I can iterate through the response array.
using (HttpClient client = new HttpClient())
{
client.BaseAddress = new Uri(URL);
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get,"");
request.Content = new StringContent(URL, Encoding.UTF8,"application/json");
Wiring this in VS Code so will need to install packages if needed.
Thank you!

You are almost there. Try (if you want a simple synchronous send):
HttpClient client = new HttpClient();
string responseString;
using (HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, new Uri("<insert your URL>"))) {
HttpResponseMessage response = client.SendAsync(request).Result;
// Get the response content as a string
responseString = response.Content.ReadAsStringAsync().Result;
}
Note that it's good practice to initialize one instance of HttpClient and reuse it to send multiple requests (rather than initialize one every time you need to send something).
Any headers, URLs and such specific to a message should be set in the HttpRequestMessage class (which should be disposed of with the "using ..." term.

Is it possible to generate headers automatically with HttpClient / RestSharp?

At the moment I am using the following RestSharp request to get a website's content:
var client = new RestClient(productLink);
var request = new RestRequest(Method.GET);
request.AddHeader("Cookie", "insert-cookie-content");
IRestResponse response = client.Execute(request);
Console.WriteLine(response.Content);
I have tried converting it into HttpClient as i will need to use the AllowRedirect property later:
var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Add("Cookie", "insert-cookie-content");
var response = await client.GetAsync(productUrl);
Console.WriteLine(response);
The URL I am trying to get a response from is: https://www.nike.com/sg/launch/t/air-max-90-orange-duck-camo
My first problem is that the HttpClient request is giving me 403 Errors whereas the RestClient request was working fine. How can I fix this?
My second problem is that the cookie expires after a couple of uses, and I have to manually get a new one from postman and insert it. Is there anyway for the request to generate its own cookie?
Here is the two fiddler responses compared: https://imgur.com/a/bZo7d9F

In case of HttpClient if you want to pass the Cookies manually through the DefaultRequestHeaders then you have to tell this to the HttpClient to do NOT use CookieContainer. You have to use HttpClientHandler's UseCookie flag to indicate it.
var client = new HttpClient(new HttpClientHandler { UseCookies = false });
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Add("Cookie", "insert-cookie-content");
var response = await client.GetAsync(productUrl);
Console.WriteLine(response);

Custom header to HttpClient request

How do I add a custom header to a HttpClient request? I am using PostAsJsonAsync method to post the JSON. The custom header that I would need to be added is
"X-Version: 1"
This is what I have done so far:
using (var client = new HttpClient()) {
client.BaseAddress = new Uri("https://api.clickatell.com/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "xxxxxxxxxxxxxxxxxxxx");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = client.PostAsJsonAsync("rest/message", svm).Result;
}

I have found the answer to my question.
client.DefaultRequestHeaders.Add("X-Version","1");
That should add a custom header to your request

Here is an answer based on that by Anubis (which is a better approach as it doesn't modify the headers for every request) but which is more equivalent to the code in the original question:
using Newtonsoft.Json;
...
var client = new HttpClient();
var httpRequestMessage = new HttpRequestMessage
{
Method = HttpMethod.Post,
RequestUri = new Uri("https://api.clickatell.com/rest/message"),
Headers = {
{ HttpRequestHeader.Authorization.ToString(), "Bearer xxxxxxxxxxxxxxxxxxx" },
{ HttpRequestHeader.Accept.ToString(), "application/json" },
{ "X-Version", "1" }
},
Content = new StringContent(JsonConvert.SerializeObject(svm))
};
var response = client.SendAsync(httpRequestMessage).Result;

var request = new HttpRequestMessage {
RequestUri = new Uri("[your request url string]"),
Method = HttpMethod.Post,
Headers = {
{ "X-Version", "1" } // HERE IS HOW TO ADD HEADERS,
{ HttpRequestHeader.Authorization.ToString(), "[your authorization token]" },
{ HttpRequestHeader.ContentType.ToString(), "multipart/mixed" },//use this content type if you want to send more than one content type
},
Content = new MultipartContent { // Just example of request sending multipart request
new ObjectContent<[YOUR JSON OBJECT TYPE]>(
new [YOUR JSON OBJECT TYPE INSTANCE](...){...},
new JsonMediaTypeFormatter(),
"application/json"), // this will add 'Content-Type' header for the first part of request
new ByteArrayContent([BINARY DATA]) {
Headers = { // this will add headers for the second part of request
{ "Content-Type", "application/Executable" },
{ "Content-Disposition", "form-data; filename=\"test.pdf\"" },
},
},
},
};

There is a Headers property in the HttpRequestMessage class. You can add custom headers there, which will be sent with each HTTP request. The DefaultRequestHeaders in the HttpClient class, on the other hand, sets headers to be sent with each request sent using that client object, hence the name Default Request Headers.
Hope this makes things more clear, at least for someone seeing this answer in future.

I have added x-api-version in HttpClient headers as below :
var client = new HttpClient(httpClientHandler)
{
BaseAddress = new Uri(callingUrl)
};
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Add("x-api-version", v2);

My two cents. I agree with heug. The accepted answer is a mind bender. Let's take a step back.
Default headers apply to all requests made by a particular HttpClient. Hence you would use default headers for shared headers.
_client.DefaultRequestHeaders.UserAgent.ParseAdd(_options.UserAgent);
However, we sometimes need headers specific to a certain request. We would therefore use something like this in the method:
public static async Task<HttpResponseMessage> GetWithHeadersAsync(this
HttpClient httpClient, string requestUri, Dictionary<string, string> headers)
{
using (var request = new HttpRequestMessage(HttpMethod.Get, requestUri))
{
foreach(var header in headers)
{
request.Headers.Add(header.Key, header.Value);
}
return await httpClient.SendAsync(request);
}
}
If you only need one additional non-default header you would simply use:
request.Headers.Add("X-Version","1")
For more help:
How to add request headers when using HttpClient

Also you can use HttpClient.PostAsync method:
using (HttpClient http_client = new HttpClient())
{
StringContent string_content = new StringContent(JsonSerializer.Serialize("{\"field\":\"field_value\"}"));
string_content.Headers.Add("X-Version","1");
using (HttpResponseMessage response = await http_client.PostAsync("http://127.0.0.1/apiMethodName", string_content))
{
if (response.IsSuccessStatusCode)
{
Console.WriteLine($"Response status code: {response.StatusCode}");
}
else
{
Console.WriteLine($"Error status code: {response.StatusCode}");
}
}
}

Just in case someone is wondering how to call httpClient.GetStreamAsync() which does not have an overload which takes HttpRequestMessage to provide custom headers you can use the above code given by #Anubis and call
await response.Content.ReadAsStreamAsync()
Especially useful if you are returning a blob url with Range Header as a FileStreamResult

.NET HttpClient Request Content-Type

I'm not sure, but it appears to me that the default implementation of .NET HttpClient library is flawed. It looks like it sets the Content-Type request value to "text/html" on a PostAsJsonAsync call. I've tried to reset the request value, but not sure if I'm doing this correctly. Any suggestions.
public async Task<string> SendPost(Model model)
{
var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = await client.PostAsJsonAsync(Url + "api/foo/", model);
response.EnsureSuccessStatusCode();
return await response.Content.ReadAsStringAsync();
}

You should set the content type. With the Accept you define what you want as response.
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
The Accept request-header field can be used to specify certain media types which are acceptable for the response. Accept headers can be used to indicate that the request is specifically limited to a small set of desired types, as in the case of a request for an in-line image.
public async Task<string> SendPost(Model model)
{
var client = new HttpClient(); //You should extract this and reuse the same instance multiple times.
var request = new HttpRequestMessage(HttpMethod.Post, Url + "api/foo");
using(var content = new StringContent(Serialize(model), Encoding.UTF8, "application/json"))
{
request.Content = content;
var response = await client.SendAsync(request).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
return await response.Content.ReadAsStringAsync().ConfigureAwait(false);
}
}

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