I use codes below to send POST request to a server:
string url = "http://myserver/method?param1=1¶m2=2"
HttpClientHandler handler = new HttpClientHandler();
HttpClient httpClient = new HttpClient(handler);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, url);
HttpResponseMessage response = await httpClient.SendAsync(request);
I don't have access to the server to debug but I want to know, is this request sent as POST or GET?
If it is GET, How can I change my code to send param1 & param2 as POST data (not in the URL)?
A cleaner alternative would be to use a Dictionary to handle parameters. They are key-value pairs after all.
private static readonly HttpClient httpclient;
static MyClassName()
{
// HttpClient is intended to be instantiated once and re-used throughout the life of an application.
// Instantiating an HttpClient class for every request will exhaust the number of sockets available under heavy loads.
// This will result in SocketException errors.
// https://learn.microsoft.com/en-us/dotnet/api/system.net.http.httpclient?view=netframework-4.7.1
httpclient = new HttpClient();
}
var url = "http://myserver/method";
var parameters = new Dictionary<string, string> { { "param1", "1" }, { "param2", "2" } };
var encodedContent = new FormUrlEncodedContent (parameters);
var response = await httpclient.PostAsync (url, encodedContent).ConfigureAwait (false);
if (response.StatusCode == HttpStatusCode.OK) {
// Do something with response. Example get content:
// var responseContent = await response.Content.ReadAsStringAsync ().ConfigureAwait (false);
}
Also dont forget to Dispose() httpclient, if you dont use the keyword using
As stated in the Remarks section of the HttpClient class in the Microsoft docs, HttpClient should be instantiated once and re-used.
Edit:
You may want to look into response.EnsureSuccessStatusCode(); instead of if (response.StatusCode == HttpStatusCode.OK).
You may want to keep your httpclient and dont Dispose() it. See: Do HttpClient and HttpClientHandler have to be disposed?
Edit:
Do not worry about using .ConfigureAwait(false) in .NET Core. For more details look at https://blog.stephencleary.com/2017/03/aspnetcore-synchronization-context.html
This is how I use it for DI:
using HttpClient httpClient = clientFactory.CreateClient("name set in builder host");
// httpClient.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", $"Token {token}");
HttpResponseMessage? res = await httpClient!.PostAsync(url, content);
try
{
res.EnsureSuccessStatusCode();
return res;
}
catch (Exception)
{
// Add error handling
}
content is:
List<KeyValuePair<string, string>> values = new()
{
new KeyValuePair<string, string>("data", "value")
};
FormUrlEncodedContent requestContent = new(values);
and clientFactory is the interface:
IHttpClientFactory
msdn interface
As Ben said, you are POSTing your request ( HttpMethod.Post specified in your code )
The querystring (get) parameters included in your url probably will not do anything.
Try this:
string url = "http://myserver/method";
string content = "param1=1¶m2=2";
HttpClientHandler handler = new HttpClientHandler();
HttpClient httpClient = new HttpClient(handler);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, url);
HttpResponseMessage response = await httpClient.SendAsync(request,content);
HTH,
bovako
Related
Hi guys this is my first time using web api and I hope you can point me in the right direction. How do I add the api key in request header using web api?
I tried to check google but i'm not sure if I'm looking at the right guide.
This is what I found > How to add and get Header values in WebApi
My goal is to make a GET request and add the API key in the request headers.
You always have key-value pair in header of any API request. For example here you have the header with key as "api_key" and value as "1234". You can add this in your Http request by the way given below.
HttpClient httpClient = new HttpClient();
HttpRequestMessage request = new HttpRequestMessage();
request.RequestUri = new Uri("Your_get_URI");
request.Method = HttpMethod.Get;
request.Headers.Add("api_key", "1234");
HttpResponseMessage response = await httpClient.SendAsync(request);
var responseString = await response.Content.ReadAsStringAsync();
var statusCode = response.StatusCode;
If you are using DI you could easily inject a configured HttpClient by doing a little setup in Startup.cs
The following is a working example of configuring a HttpClient for use with Microsoft's App Insights api. Of course you will have to change your header as needed.
public void ConfigureServices(IServiceCollection services)
{
//Somewhere in the ConfigureSerices method.
services.AddHttpClient("APPINSIGHTS_CLIENT", c =>
{
c.BaseAddress = "<API_URL_HERE>";
c.DefaultRequestHeaders.Add("x-api-key", clientKey));
}
}
Now if you inject IHttpClientFactory for use downstream, and call it will be configured and ready to be used without any fuss.
HttpClient client = factory.CreateClient("APPINSIGHTS_CLIENT");
Try this, I hope this will work for you.
using (var httpClient = new HttpClient())
{
httpClient.BaseAddress = new Uri("API URL");
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Authorization = new
System.Net.Http.Headers.AuthenticationHeaderValue("Pass your token value or API key");
HttpResponseMessage response = await httpClient.GetAsync(endpoint);
if (response.StatusCode == HttpStatusCode.OK)
{
string result = await response.Content.ReadAsStringAsync();
if (string.IsNullOrEmpty(result))
return "Success";
else
return result;
}
else if (response.StatusCode == HttpStatusCode.Unauthorized)
{
throw new UnauthorizedAccessException();
}
else
{
throw new Exception(await response.Content.ReadAsStringAsync());
}
}
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
I'm integrating a service that returns a key when I a GET request to a URL that is in the following format:
https://username:password#service.com/refresh.key
When I access the URL in my browser, it returns the new key as expected, by when I do a GET request using HttpClient I get a 401.
HttpClient _client = new HttpClient();
var response = await _client.GetAsync(#"https://username:password#service.com/refresh.key"); // Returns a 401
I think it has something to do with the '#' in the URL, but I'm not sure how to fix it, I tried replacing it with '%40', but when I do that I get a UriFormatException.
Does anyone know how to do this?
You should modify Authorization header of HttpClient, can you try the code below;
HttpClient _client = new HttpClient();
byte[] usernamePasswordBytes = Encoding.ASCII.GetBytes("user:pass");
_client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", Convert.ToBase64String(usernamePasswordBytes));
var response = await _client.GetAsync(#"https://service.com/refresh.key");
PS: Such username:pass#domain.com requests are BasicAuthentication request so in fact you try to make basic authentication request.
Hope this works for you
You don't need to provide credentials in url. Instead you can do:
using (var handler = new HttpClientHandler {Credentials = new NetworkCredential("username", "password")}) {
using (HttpClient _client = new HttpClient(handler)) {
var response = await _client.GetAsync(#"https://service.com/refresh.key");
}
}
i am looking for a simple example using .net HttpClient to POST parameters and add headers. This is super easy in RestSharp but so far i cannot see a clear way how to do this with the HttpClient.
If you want to modify request headers for every request then the easiest way to do it is by setting the DefaultRequestHeaders properties. However, if you really want to change the request headers just for a particular request then you need to use the SendAsync method and pass it a HttpRequestMessage.
[Fact]
public async Task Post_a_form_and_change_some_headers()
{
var client = new HttpClient() { BaseAddress = _BaseAddress };
var values = new Dictionary<string, string>()
{
{"Id", "6"},
{"Name", "Skis"},
{"Price", "100"},
{"Category", "Sports"}
};
var content = new FormUrlEncodedContent(values);
var request = new HttpRequestMessage()
{
RequestUri = new Uri("devnull",UriKind.Relative),
Method = HttpMethod.Post,
Content = content
};
request.Headers.ExpectContinue = false;
request.Headers.Add("custom-header","a header value");
var response = await client.SendAsync(request);
response.EnsureSuccessStatusCode();
}
I need to add http headers to the HttpClient before I send a request to a web service. How do I do that for an individual request (as opposed to on the HttpClient to all future requests)? I'm not sure if this is even possible.
var client = new HttpClient();
var task =
client.GetAsync("http://www.someURI.com")
.ContinueWith((taskwithmsg) =>
{
var response = taskwithmsg.Result;
var jsonTask = response.Content.ReadAsAsync<JsonObject>();
jsonTask.Wait();
var jsonObject = jsonTask.Result;
});
task.Wait();
Create a HttpRequestMessage, set the Method to GET, set your headers and then use SendAsync instead of GetAsync.
var client = new HttpClient();
var request = new HttpRequestMessage() {
RequestUri = new Uri("http://www.someURI.com"),
Method = HttpMethod.Get,
};
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/plain"));
var task = client.SendAsync(request)
.ContinueWith((taskwithmsg) =>
{
var response = taskwithmsg.Result;
var jsonTask = response.Content.ReadAsAsync<JsonObject>();
jsonTask.Wait();
var jsonObject = jsonTask.Result;
});
task.Wait();
When it can be the same header for all requests or you dispose the client after each request you can use the DefaultRequestHeaders.Add option:
client.DefaultRequestHeaders.Add("apikey","xxxxxxxxx");
To set custom headers ON A REQUEST, build a request with the custom header before passing it to httpclient to send to http server.
eg:
HttpClient client = HttpClients.custom().build();
HttpUriRequest request = RequestBuilder.get()
.setUri(someURL)
.setHeader(HttpHeaders.CONTENT_TYPE, "application/json")
.build();
client.execute(request);
Default header is SET ON HTTPCLIENT to send on every request to the server.