Related
I'm trying to set the Content-Type header of an HttpClient object as required by an API I am calling.
I tried setting the Content-Type like below:
using (var httpClient = new HttpClient())
{
httpClient.BaseAddress = new Uri("http://example.com/");
httpClient.DefaultRequestHeaders.Add("Accept", "application/json");
httpClient.DefaultRequestHeaders.Add("Content-Type", "application/json");
// ...
}
It allows me to add the Accept header but when I try to add Content-Type it throws the following exception:
Misused header name. Make sure request headers are used with
HttpRequestMessage, response headers with HttpResponseMessage, and
content headers with HttpContent objects.
How can I set the Content-Type header in a HttpClient request?
The content type is a header of the content, not of the request, which is why this is failing. AddWithoutValidation as suggested by Robert Levy may work, but you can also set the content type when creating the request content itself (note that the code snippet adds application/json in two places-for Accept and Content-Type headers):
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://example.com/");
client.DefaultRequestHeaders
.Accept
.Add(new MediaTypeWithQualityHeaderValue("application/json"));//ACCEPT header
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "relativeAddress");
request.Content = new StringContent("{\"name\":\"John Doe\",\"age\":33}",
Encoding.UTF8,
"application/json");//CONTENT-TYPE header
client.SendAsync(request)
.ContinueWith(responseTask =>
{
Console.WriteLine("Response: {0}", responseTask.Result);
});
For those who didn't see Johns comment to carlos solution ...
req.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
If you don't mind a small library dependency, Flurl.Http [disclosure: I'm the author] makes this uber-simple. Its PostJsonAsync method takes care of both serializing the content and setting the content-type header, and ReceiveJson deserializes the response. If the accept header is required you'll need to set that yourself, but Flurl provides a pretty clean way to do that too:
using Flurl.Http;
var result = await "http://example.com/"
.WithHeader("Accept", "application/json")
.PostJsonAsync(new { ... })
.ReceiveJson<TResult>();
Flurl uses HttpClient and Json.NET under the hood, and it's a PCL so it'll work on a variety of platforms.
PM> Install-Package Flurl.Http
try to use TryAddWithoutValidation
var client = new HttpClient();
client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json; charset=utf-8");
.Net tries to force you to obey certain standards, namely that the Content-Type header can only be specified on requests that have content (e.g. POST, PUT, etc.). Therefore, as others have indicated, the preferred way to set the Content-Type header is through the HttpContent.Headers.ContentType property.
With that said, certain APIs (such as the LiquidFiles Api, as of 2016-12-19) requires setting the Content-Type header for a GET request. .Net will not allow setting this header on the request itself -- even using TryAddWithoutValidation. Furthermore, you cannot specify a Content for the request -- even if it is of zero-length. The only way I could seem to get around this was to resort to reflection. The code (in case some else needs it) is
var field = typeof(System.Net.Http.Headers.HttpRequestHeaders)
.GetField("invalidHeaders", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static)
?? typeof(System.Net.Http.Headers.HttpRequestHeaders)
.GetField("s_invalidHeaders", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
if (field != null)
{
var invalidFields = (HashSet<string>)field.GetValue(null);
invalidFields.Remove("Content-Type");
}
_client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "text/xml");
Edit:
As noted in the comments, this field has different names in different versions of the dll. In the source code on GitHub, the field is currently named s_invalidHeaders. The example has been modified to account for this per the suggestion of #David Thompson.
For those who troubled with charset
I had very special case that the service provider didn't accept charset, and they refuse to change the substructure to allow it...
Unfortunately HttpClient was setting the header automatically through StringContent, and no matter if you pass null or Encoding.UTF8, it will always set the charset...
Today i was on the edge to change the sub-system; moving from HttpClient to anything else, that something came to my mind..., why not use reflection to empty out the "charset"? ...
And before i even try it, i thought of a way, "maybe I can change it after initialization", and that worked.
Here's how you can set the exact "application/json" header without "; charset=utf-8".
var jsonRequest = JsonSerializeObject(req, options); // Custom function that parse object to string
var stringContent = new StringContent(jsonRequest, Encoding.UTF8, "application/json");
stringContent.Headers.ContentType.CharSet = null;
return stringContent;
Note: The null value in following won't work, and append "; charset=utf-8"
return new StringContent(jsonRequest, null, "application/json");
EDIT
#DesertFoxAZ suggests that also the following code can be used and works fine. (didn't test it myself, if it work's rate and credit him in comments)
stringContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
Some extra information about .NET Core (after reading erdomke's post about setting a private field to supply the content-type on a request that doesn't have content)...
After debugging my code, I can't see the private field to set via reflection - so I thought I'd try to recreate the problem.
I have tried the following code using .Net 4.6:
HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Get, #"myUrl");
httpRequest.Content = new StringContent(string.Empty, Encoding.UTF8, "application/json");
HttpClient client = new HttpClient();
Task<HttpResponseMessage> response = client.SendAsync(httpRequest); //I know I should have used async/await here!
var result = response.Result;
And, as expected, I get an aggregate exception with the content "Cannot send a content-body with this verb-type."
However, if i do the same thing with .NET Core (1.1) - I don't get an exception. My request was quite happily answered by my server application, and the content-type was picked up.
I was pleasantly surprised about that, and I hope it helps someone!
Call AddWithoutValidation instead of Add (see this MSDN link).
Alternatively, I'm guessing the API you are using really only requires this for POST or PUT requests (not ordinary GET requests). In that case, when you call HttpClient.PostAsync and pass in an HttpContent, set this on the Headers property of that HttpContent object.
The trick is that you can just set all kinds of headers like:
HttpRequestMessage request = new HttpRequestMessage();
request.Headers.Add("Accept-Language", "en"); //works OK
but not any header. For example:
request.Headers.Add("Content-Type", "application/json");//wrong
will raise the run-time exception Misused header name. It may seem that this will work:
request.Headers.Add(
HttpRequestHeader.ContentType.ToString(), //useless
"application/json"
);
but this gives a useless header named ContentType, without the hyphen. Header names are not case-sensitive, but are very hyphen-sensitive.
The solution is to declare the encoding and type of the body when adding the body to the Content part of the http request:
string Body = "...";
request.Content =
new StringContent(Body, Encoding.UTF8, "application/json");
Only then the applicable http header is automatically added to the request:
Content-Type: application/json; charset=utf-8
It was hard to find this out, with Fiddler, on a machine without a proxy server. Visual Studio used to have a Network Tool where you could inspect all headers, but only in version 2015, not in newer versions 2017 or 2022. If you use the debugger to inspect request.Headers, you will not find the header added automagically by StringContent().
var content = new JsonContent();
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
content.Headers.ContentType.Parameters.Add(new NameValueHeaderValue("charset", "utf-8"));
content.Headers.ContentType.Parameters.Add(new NameValueHeaderValue("IEEE754Compatible", "true"));
It's all what you need.
With using Newtonsoft.Json, if you need a content as json string.
public class JsonContent : HttpContent
{
private readonly MemoryStream _stream = new MemoryStream();
~JsonContent()
{
_stream.Dispose();
}
public JsonContent(object value)
{
Headers.ContentType = new MediaTypeHeaderValue("application/json");
using (var contexStream = new MemoryStream())
using (var jw = new JsonTextWriter(new StreamWriter(contexStream)) { Formatting = Formatting.Indented })
{
var serializer = new JsonSerializer();
serializer.Serialize(jw, value);
jw.Flush();
contexStream.Position = 0;
contexStream.WriteTo(_stream);
}
_stream.Position = 0;
}
private JsonContent(string content)
{
Headers.ContentType = new MediaTypeHeaderValue("application/json");
using (var contexStream = new MemoryStream())
using (var sw = new StreamWriter(contexStream))
{
sw.Write(content);
sw.Flush();
contexStream.Position = 0;
contexStream.WriteTo(_stream);
}
_stream.Position = 0;
}
protected override Task SerializeToStreamAsync(Stream stream, TransportContext context)
{
return _stream.CopyToAsync(stream);
}
protected override bool TryComputeLength(out long length)
{
length = _stream.Length;
return true;
}
public static HttpContent FromFile(string filepath)
{
var content = File.ReadAllText(filepath);
return new JsonContent(content);
}
public string ToJsonString()
{
return Encoding.ASCII.GetString(_stream.GetBuffer(), 0, _stream.GetBuffer().Length).Trim();
}
}
It appears that Microsoft tries to force the developers to follow their standards, without even giving any options or settings to do otherwise, which is really a shame especially given that this is a client and we are dictated by the server side requirements, especially given that Microsoft server side frameworks themselves require it!
So basically Microsoft tries to force us good habits when connecting to their server technologies that force us non good habits...
If anyone from Microsoft is reading this, then please fix it...
Either way for anyone that needs the content-type header for Get etc., while in an older .Net version it is possible to use the answer of #erdomke at https://stackoverflow.com/a/41231353/640195 this unfortunately no longer works in the newer .Net core versions.
The following code has been tested to work with .Net core 3.1 and from the source code on GitHub it looks like it should work with newer .Net versions as well.
private void FixContentTypeHeaders()
{
var assembly = typeof(System.Net.Http.Headers.HttpRequestHeaders).Assembly;
var assemblyTypes = assembly.GetTypes();
var knownHeaderType = assemblyTypes.FirstOrDefault(n => n.Name == "KnownHeader");
var headerTypeField = knownHeaderType?
.GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)
.FirstOrDefault(n => n.Name.Contains("HeaderType"));
if (headerTypeField is null) return;
var headerTypeFieldType = headerTypeField.FieldType;
var newValue = Enum.Parse(headerTypeFieldType, "All");
var knownHeadersType = assemblyTypes.FirstOrDefault(n => n.Name == "KnownHeaders");
var contentTypeObj = knownHeadersType.GetFields().FirstOrDefault(n => n.Name == "ContentType").GetValue(null);
if (contentTypeObj is null) return;
headerTypeField.SetValue(contentTypeObj, newValue);
}
You can use this it will be work!
HttpRequestMessage msg = new HttpRequestMessage(HttpMethod.Get,"URL");
msg.Content = new StringContent(string.Empty, Encoding.UTF8, "application/json");
HttpResponseMessage response = await _httpClient.SendAsync(msg);
response.EnsureSuccessStatusCode();
string json = await response.Content.ReadAsStringAsync();
Ok, it's not HTTPClient but if u can use it, WebClient is quite easy:
using (var client = new System.Net.WebClient())
{
client.Headers.Add("Accept", "application/json");
client.Headers.Add("Content-Type", "application/json; charset=utf-8");
client.DownloadString(...);
}
try to use HttpClientFactory
services.AddSingleton<WebRequestXXX>()
.AddHttpClient<WebRequestXXX>("ClientX", config =>
{
config.BaseAddress = new System.Uri("https://jsonplaceholder.typicode.com");
config.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
config.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json; charset=utf-8");
});
======================
public class WebRequestXXXX
{
private readonly IHttpClientFactory _httpClientFactory;
public WebRequestXXXX(IHttpClientFactory httpClientFactory)
{
_httpClientFactory = httpClientFactory;
}
public List<Posts> GetAllPosts()
{
using (var _client = _httpClientFactory.CreateClient("ClientX"))
{
var response = _client.GetAsync("/posts").Result;
if (response.IsSuccessStatusCode)
{
var itemString = response.Content.ReadAsStringAsync().Result;
var itemJson = System.Text.Json.JsonSerializer.Deserialize<List<Posts>>(itemString,
new System.Text.Json.JsonSerializerOptions
{
PropertyNameCaseInsensitive = true
});
return itemJson;
}
else
{
return new List<Posts>();
}
}
}
}
I got the answer whith RestSharp:
private async Task<string> GetAccessTokenAsync()
{
var client = new RestClient(_baseURL);
var request = new RestRequest("auth/v1/login", Method.POST, DataFormat.Json);
request.AddHeader("Content-Type", "application/json");
request.AddHeader("x-api-key", _apiKey);
request.AddHeader("Accept-Language", "br");
request.AddHeader("x-client-tenant", "1");
...
}
It worked for me.
You need to do it like this:
HttpContent httpContent = new StringContent(#"{ the json string }");
httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage message = client.PostAsync(#"{url}", httpContent).Result;
For those wanting to set the Content-Type to Json specifically, you can use the extension method PostAsJsonAsync.
using System.Net.Http.Json; //this is needed for PostAsJsonAsync to work
//....
HttpClient client = new HttpClient();
HttpResponseMessage response = await
client.PostAsJsonAsync("http://example.com/" + "relativeAddress",
new
{
name = "John Doe",
age = 33
});
//Do what you need to do with your response
The advantage here is cleaner code and you get to avoid stringified json. More details can be found at: https://learn.microsoft.com/en-us/previous-versions/aspnet/hh944339(v=vs.118)
I find it most simple and easy to understand in the following way:
async Task SendPostRequest()
{
HttpClient client = new HttpClient();
var requestContent = new StringContent(<content>);
requestContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
var response = await client.PostAsync(<url>, requestContent);
var responseString = await response.Content.ReadAsStringAsync();
}
...
SendPostRequest().Wait();
I end up having similar issue.
So I discovered that the Software PostMan can generate code when clicking the "Code" button at upper/left corner. From that we can see what going on "under the hood" and the HTTP call is generated in many code language; curl command, C# RestShart, java, nodeJs, ...
That helped me a lot and instead of using .Net base HttpClient I ended up using RestSharp nuget package.
Hope that can help someone else!
Api returned
"Unsupported Media Type","status":415
Adding ContentType to the jsonstring did the magic and this is my script working 100% as of today
using (var client = new HttpClient())
{
var endpoint = "api/endpoint;
var userName = "xxxxxxxxxx";
var passwd = "xxxxxxxxxx";
var content = new StringContent(jsonString, Encoding.UTF8, "application/json");
var authToken = Encoding.ASCII.GetBytes($"{userName}:{passwd}");
client.BaseAddress = new Uri("https://example.com/");
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(authToken));
HttpResponseMessage response = await client.PostAsync(endpoint, content);
if (response.IsSuccessStatusCode)
{
// Get the URI of the created resource.
Uri returnUrl = response.Headers.Location;
Console.WriteLine(returnUrl);
}
string responseBody = await response.Content.ReadAsStringAsync();
return responseBody;
}
For my scenario, a third-party API was creating the HttpRequestMessage, so I was not able to use the top-voted answers to resolve the issue. And I didn't like the idea of messing with reflection so the other answers didn't work either.
Instead, I extended from AndroidMessageHandler and used this new class as a parameter to HttpClient. AndroidMessageHandler contains the method SendAsync which can be overridden in order to make changes to the HttpRequestMessage object before it is sent. If you don't have access to the Android Xamarin libaries, you may be able to figure something out with HttpMessageHandler.
public class XamarinHttpMessageHandler : global::Xamarin.Android.Net.AndroidMessageHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
// Here I make check that I'm only modifying a specific request
// and not all of them.
if (request.RequestUri != null && request.RequestUri.AbsolutePath.EndsWith("download") && request.Content != null)
{
request.Content.Headers.Add("Content-Type", "text/plain");
}
return base.SendAsync(request, cancellationToken);
}
}
Then to use:
var client = new HttpClient(new XamarinHttpMessageHandler());
So if you're trying to do a /$batch OData request like this Microsoft article demonstrates where you're supposed to have a Content-Type header like:
Content-Type: multipart/mixed;boundary=batch_d3bcb804-ee77-4921-9a45-761f98d32029
string headerValue = "multipart/mixed;boundary=batch_d3bcb804-ee77-4921-9a45-761f98d32029";
//You need to set it like thus:
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse(headerValue);
Again, the magic you need is: MediaTypeHeaderValue.Parse(...)
stringContent.Headers.ContentType = new MediaTypeHeaderValue(contentType);
And 🎉 YES! 🎉 ... that cleared up the problem with ATS REST API: SharedKey works now! 😄 👍 🍻
Source: https://github.com/dotnet/runtime/issues/17036#issuecomment-212046628
I'm trying to set the Content-Type header of an HttpClient object as required by an API I am calling.
I tried setting the Content-Type like below:
using (var httpClient = new HttpClient())
{
httpClient.BaseAddress = new Uri("http://example.com/");
httpClient.DefaultRequestHeaders.Add("Accept", "application/json");
httpClient.DefaultRequestHeaders.Add("Content-Type", "application/json");
// ...
}
It allows me to add the Accept header but when I try to add Content-Type it throws the following exception:
Misused header name. Make sure request headers are used with
HttpRequestMessage, response headers with HttpResponseMessage, and
content headers with HttpContent objects.
How can I set the Content-Type header in a HttpClient request?
The content type is a header of the content, not of the request, which is why this is failing. AddWithoutValidation as suggested by Robert Levy may work, but you can also set the content type when creating the request content itself (note that the code snippet adds application/json in two places-for Accept and Content-Type headers):
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://example.com/");
client.DefaultRequestHeaders
.Accept
.Add(new MediaTypeWithQualityHeaderValue("application/json"));//ACCEPT header
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "relativeAddress");
request.Content = new StringContent("{\"name\":\"John Doe\",\"age\":33}",
Encoding.UTF8,
"application/json");//CONTENT-TYPE header
client.SendAsync(request)
.ContinueWith(responseTask =>
{
Console.WriteLine("Response: {0}", responseTask.Result);
});
For those who didn't see Johns comment to carlos solution ...
req.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
If you don't mind a small library dependency, Flurl.Http [disclosure: I'm the author] makes this uber-simple. Its PostJsonAsync method takes care of both serializing the content and setting the content-type header, and ReceiveJson deserializes the response. If the accept header is required you'll need to set that yourself, but Flurl provides a pretty clean way to do that too:
using Flurl.Http;
var result = await "http://example.com/"
.WithHeader("Accept", "application/json")
.PostJsonAsync(new { ... })
.ReceiveJson<TResult>();
Flurl uses HttpClient and Json.NET under the hood, and it's a PCL so it'll work on a variety of platforms.
PM> Install-Package Flurl.Http
try to use TryAddWithoutValidation
var client = new HttpClient();
client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json; charset=utf-8");
.Net tries to force you to obey certain standards, namely that the Content-Type header can only be specified on requests that have content (e.g. POST, PUT, etc.). Therefore, as others have indicated, the preferred way to set the Content-Type header is through the HttpContent.Headers.ContentType property.
With that said, certain APIs (such as the LiquidFiles Api, as of 2016-12-19) requires setting the Content-Type header for a GET request. .Net will not allow setting this header on the request itself -- even using TryAddWithoutValidation. Furthermore, you cannot specify a Content for the request -- even if it is of zero-length. The only way I could seem to get around this was to resort to reflection. The code (in case some else needs it) is
var field = typeof(System.Net.Http.Headers.HttpRequestHeaders)
.GetField("invalidHeaders", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static)
?? typeof(System.Net.Http.Headers.HttpRequestHeaders)
.GetField("s_invalidHeaders", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
if (field != null)
{
var invalidFields = (HashSet<string>)field.GetValue(null);
invalidFields.Remove("Content-Type");
}
_client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "text/xml");
Edit:
As noted in the comments, this field has different names in different versions of the dll. In the source code on GitHub, the field is currently named s_invalidHeaders. The example has been modified to account for this per the suggestion of #David Thompson.
For those who troubled with charset
I had very special case that the service provider didn't accept charset, and they refuse to change the substructure to allow it...
Unfortunately HttpClient was setting the header automatically through StringContent, and no matter if you pass null or Encoding.UTF8, it will always set the charset...
Today i was on the edge to change the sub-system; moving from HttpClient to anything else, that something came to my mind..., why not use reflection to empty out the "charset"? ...
And before i even try it, i thought of a way, "maybe I can change it after initialization", and that worked.
Here's how you can set the exact "application/json" header without "; charset=utf-8".
var jsonRequest = JsonSerializeObject(req, options); // Custom function that parse object to string
var stringContent = new StringContent(jsonRequest, Encoding.UTF8, "application/json");
stringContent.Headers.ContentType.CharSet = null;
return stringContent;
Note: The null value in following won't work, and append "; charset=utf-8"
return new StringContent(jsonRequest, null, "application/json");
EDIT
#DesertFoxAZ suggests that also the following code can be used and works fine. (didn't test it myself, if it work's rate and credit him in comments)
stringContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
Some extra information about .NET Core (after reading erdomke's post about setting a private field to supply the content-type on a request that doesn't have content)...
After debugging my code, I can't see the private field to set via reflection - so I thought I'd try to recreate the problem.
I have tried the following code using .Net 4.6:
HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Get, #"myUrl");
httpRequest.Content = new StringContent(string.Empty, Encoding.UTF8, "application/json");
HttpClient client = new HttpClient();
Task<HttpResponseMessage> response = client.SendAsync(httpRequest); //I know I should have used async/await here!
var result = response.Result;
And, as expected, I get an aggregate exception with the content "Cannot send a content-body with this verb-type."
However, if i do the same thing with .NET Core (1.1) - I don't get an exception. My request was quite happily answered by my server application, and the content-type was picked up.
I was pleasantly surprised about that, and I hope it helps someone!
Call AddWithoutValidation instead of Add (see this MSDN link).
Alternatively, I'm guessing the API you are using really only requires this for POST or PUT requests (not ordinary GET requests). In that case, when you call HttpClient.PostAsync and pass in an HttpContent, set this on the Headers property of that HttpContent object.
The trick is that you can just set all kinds of headers like:
HttpRequestMessage request = new HttpRequestMessage();
request.Headers.Add("Accept-Language", "en"); //works OK
but not any header. For example:
request.Headers.Add("Content-Type", "application/json");//wrong
will raise the run-time exception Misused header name. It may seem that this will work:
request.Headers.Add(
HttpRequestHeader.ContentType.ToString(), //useless
"application/json"
);
but this gives a useless header named ContentType, without the hyphen. Header names are not case-sensitive, but are very hyphen-sensitive.
The solution is to declare the encoding and type of the body when adding the body to the Content part of the http request:
string Body = "...";
request.Content =
new StringContent(Body, Encoding.UTF8, "application/json");
Only then the applicable http header is automatically added to the request:
Content-Type: application/json; charset=utf-8
It was hard to find this out, with Fiddler, on a machine without a proxy server. Visual Studio used to have a Network Tool where you could inspect all headers, but only in version 2015, not in newer versions 2017 or 2022. If you use the debugger to inspect request.Headers, you will not find the header added automagically by StringContent().
var content = new JsonContent();
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
content.Headers.ContentType.Parameters.Add(new NameValueHeaderValue("charset", "utf-8"));
content.Headers.ContentType.Parameters.Add(new NameValueHeaderValue("IEEE754Compatible", "true"));
It's all what you need.
With using Newtonsoft.Json, if you need a content as json string.
public class JsonContent : HttpContent
{
private readonly MemoryStream _stream = new MemoryStream();
~JsonContent()
{
_stream.Dispose();
}
public JsonContent(object value)
{
Headers.ContentType = new MediaTypeHeaderValue("application/json");
using (var contexStream = new MemoryStream())
using (var jw = new JsonTextWriter(new StreamWriter(contexStream)) { Formatting = Formatting.Indented })
{
var serializer = new JsonSerializer();
serializer.Serialize(jw, value);
jw.Flush();
contexStream.Position = 0;
contexStream.WriteTo(_stream);
}
_stream.Position = 0;
}
private JsonContent(string content)
{
Headers.ContentType = new MediaTypeHeaderValue("application/json");
using (var contexStream = new MemoryStream())
using (var sw = new StreamWriter(contexStream))
{
sw.Write(content);
sw.Flush();
contexStream.Position = 0;
contexStream.WriteTo(_stream);
}
_stream.Position = 0;
}
protected override Task SerializeToStreamAsync(Stream stream, TransportContext context)
{
return _stream.CopyToAsync(stream);
}
protected override bool TryComputeLength(out long length)
{
length = _stream.Length;
return true;
}
public static HttpContent FromFile(string filepath)
{
var content = File.ReadAllText(filepath);
return new JsonContent(content);
}
public string ToJsonString()
{
return Encoding.ASCII.GetString(_stream.GetBuffer(), 0, _stream.GetBuffer().Length).Trim();
}
}
It appears that Microsoft tries to force the developers to follow their standards, without even giving any options or settings to do otherwise, which is really a shame especially given that this is a client and we are dictated by the server side requirements, especially given that Microsoft server side frameworks themselves require it!
So basically Microsoft tries to force us good habits when connecting to their server technologies that force us non good habits...
If anyone from Microsoft is reading this, then please fix it...
Either way for anyone that needs the content-type header for Get etc., while in an older .Net version it is possible to use the answer of #erdomke at https://stackoverflow.com/a/41231353/640195 this unfortunately no longer works in the newer .Net core versions.
The following code has been tested to work with .Net core 3.1 and from the source code on GitHub it looks like it should work with newer .Net versions as well.
private void FixContentTypeHeaders()
{
var assembly = typeof(System.Net.Http.Headers.HttpRequestHeaders).Assembly;
var assemblyTypes = assembly.GetTypes();
var knownHeaderType = assemblyTypes.FirstOrDefault(n => n.Name == "KnownHeader");
var headerTypeField = knownHeaderType?
.GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)
.FirstOrDefault(n => n.Name.Contains("HeaderType"));
if (headerTypeField is null) return;
var headerTypeFieldType = headerTypeField.FieldType;
var newValue = Enum.Parse(headerTypeFieldType, "All");
var knownHeadersType = assemblyTypes.FirstOrDefault(n => n.Name == "KnownHeaders");
var contentTypeObj = knownHeadersType.GetFields().FirstOrDefault(n => n.Name == "ContentType").GetValue(null);
if (contentTypeObj is null) return;
headerTypeField.SetValue(contentTypeObj, newValue);
}
You can use this it will be work!
HttpRequestMessage msg = new HttpRequestMessage(HttpMethod.Get,"URL");
msg.Content = new StringContent(string.Empty, Encoding.UTF8, "application/json");
HttpResponseMessage response = await _httpClient.SendAsync(msg);
response.EnsureSuccessStatusCode();
string json = await response.Content.ReadAsStringAsync();
Ok, it's not HTTPClient but if u can use it, WebClient is quite easy:
using (var client = new System.Net.WebClient())
{
client.Headers.Add("Accept", "application/json");
client.Headers.Add("Content-Type", "application/json; charset=utf-8");
client.DownloadString(...);
}
try to use HttpClientFactory
services.AddSingleton<WebRequestXXX>()
.AddHttpClient<WebRequestXXX>("ClientX", config =>
{
config.BaseAddress = new System.Uri("https://jsonplaceholder.typicode.com");
config.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
config.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json; charset=utf-8");
});
======================
public class WebRequestXXXX
{
private readonly IHttpClientFactory _httpClientFactory;
public WebRequestXXXX(IHttpClientFactory httpClientFactory)
{
_httpClientFactory = httpClientFactory;
}
public List<Posts> GetAllPosts()
{
using (var _client = _httpClientFactory.CreateClient("ClientX"))
{
var response = _client.GetAsync("/posts").Result;
if (response.IsSuccessStatusCode)
{
var itemString = response.Content.ReadAsStringAsync().Result;
var itemJson = System.Text.Json.JsonSerializer.Deserialize<List<Posts>>(itemString,
new System.Text.Json.JsonSerializerOptions
{
PropertyNameCaseInsensitive = true
});
return itemJson;
}
else
{
return new List<Posts>();
}
}
}
}
I got the answer whith RestSharp:
private async Task<string> GetAccessTokenAsync()
{
var client = new RestClient(_baseURL);
var request = new RestRequest("auth/v1/login", Method.POST, DataFormat.Json);
request.AddHeader("Content-Type", "application/json");
request.AddHeader("x-api-key", _apiKey);
request.AddHeader("Accept-Language", "br");
request.AddHeader("x-client-tenant", "1");
...
}
It worked for me.
You need to do it like this:
HttpContent httpContent = new StringContent(#"{ the json string }");
httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage message = client.PostAsync(#"{url}", httpContent).Result;
For those wanting to set the Content-Type to Json specifically, you can use the extension method PostAsJsonAsync.
using System.Net.Http.Json; //this is needed for PostAsJsonAsync to work
//....
HttpClient client = new HttpClient();
HttpResponseMessage response = await
client.PostAsJsonAsync("http://example.com/" + "relativeAddress",
new
{
name = "John Doe",
age = 33
});
//Do what you need to do with your response
The advantage here is cleaner code and you get to avoid stringified json. More details can be found at: https://learn.microsoft.com/en-us/previous-versions/aspnet/hh944339(v=vs.118)
I find it most simple and easy to understand in the following way:
async Task SendPostRequest()
{
HttpClient client = new HttpClient();
var requestContent = new StringContent(<content>);
requestContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
var response = await client.PostAsync(<url>, requestContent);
var responseString = await response.Content.ReadAsStringAsync();
}
...
SendPostRequest().Wait();
I end up having similar issue.
So I discovered that the Software PostMan can generate code when clicking the "Code" button at upper/left corner. From that we can see what going on "under the hood" and the HTTP call is generated in many code language; curl command, C# RestShart, java, nodeJs, ...
That helped me a lot and instead of using .Net base HttpClient I ended up using RestSharp nuget package.
Hope that can help someone else!
Api returned
"Unsupported Media Type","status":415
Adding ContentType to the jsonstring did the magic and this is my script working 100% as of today
using (var client = new HttpClient())
{
var endpoint = "api/endpoint;
var userName = "xxxxxxxxxx";
var passwd = "xxxxxxxxxx";
var content = new StringContent(jsonString, Encoding.UTF8, "application/json");
var authToken = Encoding.ASCII.GetBytes($"{userName}:{passwd}");
client.BaseAddress = new Uri("https://example.com/");
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(authToken));
HttpResponseMessage response = await client.PostAsync(endpoint, content);
if (response.IsSuccessStatusCode)
{
// Get the URI of the created resource.
Uri returnUrl = response.Headers.Location;
Console.WriteLine(returnUrl);
}
string responseBody = await response.Content.ReadAsStringAsync();
return responseBody;
}
For my scenario, a third-party API was creating the HttpRequestMessage, so I was not able to use the top-voted answers to resolve the issue. And I didn't like the idea of messing with reflection so the other answers didn't work either.
Instead, I extended from AndroidMessageHandler and used this new class as a parameter to HttpClient. AndroidMessageHandler contains the method SendAsync which can be overridden in order to make changes to the HttpRequestMessage object before it is sent. If you don't have access to the Android Xamarin libaries, you may be able to figure something out with HttpMessageHandler.
public class XamarinHttpMessageHandler : global::Xamarin.Android.Net.AndroidMessageHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
// Here I make check that I'm only modifying a specific request
// and not all of them.
if (request.RequestUri != null && request.RequestUri.AbsolutePath.EndsWith("download") && request.Content != null)
{
request.Content.Headers.Add("Content-Type", "text/plain");
}
return base.SendAsync(request, cancellationToken);
}
}
Then to use:
var client = new HttpClient(new XamarinHttpMessageHandler());
So if you're trying to do a /$batch OData request like this Microsoft article demonstrates where you're supposed to have a Content-Type header like:
Content-Type: multipart/mixed;boundary=batch_d3bcb804-ee77-4921-9a45-761f98d32029
string headerValue = "multipart/mixed;boundary=batch_d3bcb804-ee77-4921-9a45-761f98d32029";
//You need to set it like thus:
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse(headerValue);
Again, the magic you need is: MediaTypeHeaderValue.Parse(...)
stringContent.Headers.ContentType = new MediaTypeHeaderValue(contentType);
And 🎉 YES! 🎉 ... that cleared up the problem with ATS REST API: SharedKey works now! 😄 👍 🍻
Source: https://github.com/dotnet/runtime/issues/17036#issuecomment-212046628
I am doing a bit of research into building a program to use the Australian crypto trading platform Coinspot. I have used API's in the past but barley used "POST" method, Coinspots information and documentation is sooooooo poor (probs because they don't want you to use it) but i figured ill give it a whirl anyways.
Question:
How do you use a POST method if you do not know the order in which to send data? (is there a standard or is every API different).
i have an API key and a secret API key to send for authorisation but still get access denied.
Is there anyway you can use code to request an order or something like you do when you pull a json to string?
WebRequest request = WebRequest.Create("https://www.coinspot.com.au/api/ro/balances");
request.Method = "POST";
request.Headers.Add("key", APIKEY);
request.ContentType = "application/json";
request.GetResponse(); //THIS IS WHERE IT ERRORS WITH AUTHENTICATION
sorry if its a scrub question but i think im looking at this the right way, i am also using .NET library json newtonsoft so any information on this would be fantastic!!
.NET Core interpretation of the somewhat dated yet functional CoinSpot node.js api client
var nonce = Utility.GetEpochTime();
var postData = new { nonce };
var jsonMessage = postData.ToJson();
var hmac = new HMACSHA512(Encoding.ASCII.GetBytes("CoinSpotSecret"));
var byteArray = Encoding.ASCII.GetBytes(jsonMessage);
using (var stream = new MemoryStream(byteArray)) {
var hash = hmac.ComputeHash(stream).Aggregate("", (s, e) => s + String.Format("{0:x2}", e), s => s);
var uri = new Uri("https://www.coinspot.com.au/api/ro/my/balances", UriKind.Absolute);
var content = new StringContent(
jsonMessage,
System.Text.Encoding.UTF8,
"application/json"
);
content.Headers.Add("sign", hash);
content.Headers.Add("key", "CoinSpotKey");
var response = await httpClient.PostAsync(uri, content);
if (response.IsSuccessStatusCode) {
return await response.Content.ReadAsStringAsync();
}
}
Currently to send a parameterized GET request to an API interface I am writing the following code:
api/master/city/filter?cityid=1&citycode='ny'
But I see that there is a limit on the URL length of 2,083 characters.
To avoid this I would like to send the parameters in json format in the content body for a GET request.
However, I see that none of the Get methods for the HttpClient allow for a content body to be sent. For the POST I could see there is a method within HttpClient named PostAsync that allows for a content body.
Is there a way to send parameters for a GET request not in the URL in order to avoid the URL length limit?
Please read the caveats at the end of this answer as to why HTTP GET requests with bodies are, in general, not advised.
If you are using .NET Core, the standard HttpClient can do this out-of-the-box. For example, to send a GET request with a JSON body:
HttpClient client = ...
...
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = new Uri("some url"),
Content = new StringContent("some json", Encoding.UTF8, MediaTypeNames.Application.Json /* or "application/json" in older versions */),
};
var response = await client.SendAsync(request).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
var responseBody = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
.NET Framework doesn't support this out-of-the-box (you will receive a ProtocolViolationException if you try the above code). Thankfully Microsoft has provided the System.Net.Http.WinHttpHandler package that does support the functionality - simply install and use it instead of the default HttpClientHandler when constructing your HttpClient instances:
var handler = new WinHttpHandler();
var client = new HttpClient(handler);
<rest of code as above>
Reference: https://github.com/dotnet/runtime/issues/25485#issuecomment-467261945
Caveats:
HTTP GET with a body is a somewhat unconventional construct that falls in a gray area of the HTTP specification - the end result is that many older pieces of software either cannot handle such a request at all, or will explicitly reject it because they believe it to be malformed. You need to make very sure that the endpoint you're trying to send such a request to does support it, or at best you will get an HTTP error code back; at worst the body will be silently discarded. This can lead to some head-scratching debugging!
Caching proxy servers, again particularly older ones, may cache GET requests based only on the URL because they don't expect a body to be present. This could either result in the least recent request being cached forever (which will break your software), or that the only request ever cached is the most recent one issued (which will prevent caching from working as intended). Again, this can be very painful to figure out.
I can't use .NET core and I don't want to install System.Net.Http.WinHttpHandler, which has a ton of dependencies.
I solved it by using reflection, to trick WebRequest that it is legal to send body with a GET request (which is according to latest RFC). What I do is to set ContentBodyNotAllowed to false for HTTP verb "GET".
var request = WebRequest.Create(requestUri);
request.ContentType = "application/json";
request.Method = "GET";
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write("<Json string here>");
}
var response = (HttpWebResponse)request.GetResponse();
Note, however, that the attribute ContentBodyNotAllowed belongs to a static field, so when its value changes, it remains in effect for the rest of the program. That's not a problem for my purposes.
I use WebRequest.
The value is in variable json.
var request = WebRequest.Create(requestUri);
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
request.ContentType = "application/json";
request.Method = "GET";
request.Headers.Add("Authorization", "Bearer " + Token);
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write(JsonConvert.SerializeObject(Entity));
}
var response = request.GetResponse();
var responseStream = response.GetResponseStream();
if (responseStream != null)
{
var myStreamReader = new StreamReader(responseStream, Encoding.Default);
var resultEntity= myStreamReader.ReadToEnd();
myStreamReader.ReadToEnd());
}
responseStream.Close();
response.Close();
After spending a lot of time I couldn't make neither HttpClient nor WebRequest work in my .Net Core project, apparently the server was not getting my data and it returned an error saying some specific data was not available in my request. At last only RestSharp worked in my case (the variable myData is a Dictionary<string,string> instance in the following code):
var client = new RestClient("some url");
var request = new RestRequest(Method.GET);
foreach (var d in myData)
request.AddParameter(d.Key, d.Value);
var result = (await client.ExecuteAsync(request)).Content;
similar to above answer but less code
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = targetUri,
Content = new StringContent(payload.Payload),
};
var response = await client.SendAsync(request).ConfigureAwait(false);
var responseInfo = await response.Content.ReadAsStringAsync();
I am currently working with an internal API and visual studio (new to both of them). I am trying to submit a GET request to the server which will give me a JSON with the user info. One of the field in the expected JSON response is connect_status which shows true if its connecting and false once the connection is done meaning the response has been received. So far I have been working with the following using Sleep to wait for a bit until getting the response.
bool isConnected;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://localhost");
request.Method = WebRequestMethods.Http.Get;
request.ContentType = "application/json";
System.Threading.Thread.Sleep(10000);
do
{
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream receiveStream = response.GetResponseStream();
StreamReader info = new StreamReader(receiveStream);
string json = info.ReadToEnd();
accountInfo user1 = JsonConvert.DeserializeObject<accountInfo>(json);
Console.WriteLine(jsonResponse);
isConnected = user1.connect_status;
}
while (isConnected == true);
The problem with this is that I have to wait for a longer time, the time it takes is variable and that's why I have to set a higher sleep time. Alsosomeimtes 10 seconds might not be enough and in that case when the do while loop loops the second time I get an exception at while(isConnected==true) saying
NUllReferenceException was unhandled. Object reference not set to an
instance of an object.
What would be a better/different way of doing this as I don't think the way I am doing is right.
One option here, if using .NET 4.5:
HttpMessageHandler handler = new HttpClientHandler { CookieContainer = yourCookieContainer };
HttpClient client = new HttpClient(handler) {
BaseAddress = new Uri("http://localhost")
};
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpContent content = new StringContent("dataForTheServerIfAny");
HttpResponseMessage response = await client.GetAsync("relativeActionUri", content);
string json = await response.Content.ReadAsStringAsync();
accountInfo user1 = JsonConvert.DeserializeObject<accountInfo>(json);
This way you let .NET take care of that waiting and such for you.