I have written a following code to perform an XML request using .NET's HttpWebClient library like this:
public async Task<string> DoRequest()
{
using (var httpClient = new HttpClient())
{
string requestXML = "My xml here...";
var request = new HttpRequestMessage(HttpMethod.Post, "example.com");
request.Content = new StringContent(requestXML, Encoding.UTF8, "text/xml");
var response = await httpClient.SendAsync(request);
return await response.Content.ReadAsStringAsync();
}
}
And in the main function of the console application:
Klijent test= new Klijent();
var res = test.DoRequest();
But the res return type is always showing me this:
Id = 1, Status = WaitingForActivation, Method = "{null}", Result = "{Not yet computed}"
How do I actually perform the request with this library? What am I doing wrong here??
Just simply wait for result
var res = test.DoRequest().Result;
You are expecting immediate result, even though you code is asynchronous.
Related
I am not getting any response - no error, no bad request status, etc. - when I send a post request to this API route. postData is simply a JSON object. The funny thing here is this: When i send post data as a string instead of an object, I can get a response.
View the code below:
[HttpPost]
[Route("api/updateStaffs/")]
public async Task<object> UpdateStaff([FromBody] object postData)
{
string _apiUrl = "http://localhost:5000/system/getToken";
string _baseAddress = "http://localhost:5000/system/getToken";
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(_baseAddress);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
var responseMessage = await client.PostAsync(_apiUrl, new StringContent(postData.ToString(), Encoding.UTF8, "application/json"));
if (responseMessage.IsSuccessStatusCode)
{
var response = Request.CreateResponse(HttpStatusCode.OK);
response.Content = responseMessage.Content;
return ResponseMessage(response);
}
}
return NotFound();
}
No response:
var postData = new {
user = "test"
pass = "hey"
};
var responseMessage = await client.PostAsync(_apiUrl, new StringContent(postData.ToString(), Encoding.UTF8, "application/json"));
OR
var responseMessage = await client.PostAsync(_apiUrl, new StringContent("{}", Encoding.UTF8, "application/json"));
Will get response:
var responseMessage = await client.PostAsync(_apiUrl, new StringContent("blahblah", Encoding.UTF8, "application/json"));
The receiving API is a third-party application so I am unable to verify if this error is on the other end.
Thanks.
If you dont want to use PostAsJsonAsync
You need to serialize your anonymous type to JSON, the most common tool for this is Json.NET
var jsonData = JsonConvert.SerializeObject(postData);
Then you need to construct a content object to send this data, here we can use ByteArrayContent but you can use a different type
var buffer = System.Text.Encoding.UTF8.GetBytes(jsonData);
var byteContent = new ByteArrayContent(buffer);
Then send the request
var responseMessage = await client.PostAsync(_apiUrl, byteContent);
Figured out the issue. Have to use HttpVersion10 instead of HttpVersion11.
I have given below the sample code, I am calling web API but I am struggling to pass the parameter in the console application.
C# code:
HttpClient client = new HttpClient();
var responseTask = client.GetAsync("<web api name>");
responseTask.Wait();
HttpRequestMessage rm = new HttpRequestMessage();
var headers = rm.Headers;
client.DefaultRequestHeaders.Add("client_id", "1234xv");
client.DefaultRequestHeaders.Add("client_secret", "7dfdfsd");
if (responseTask.IsCompleted)
{
var result = responseTask.Result;
if (result.IsSuccessStatusCode)
{
var messageTask = result.Content.ReadAsStringAsync();
messageTask.Wait();
Console.WriteLine("Message from Web API:" + messageTask.Result);
Console.ReadLine();
}
}
You were making the GET call much early, even before adding the parameters to the HTTP headers. You need to add the params and then call the GetAsync().
See the modified code below,
using (HttpClient client = new HttpClient())
{
client.DefaultRequestHeaders.Add("client_id", "1234xv");
client.DefaultRequestHeaders.Add("client_secret", "7dfdfsd");
var responseTask = client.GetAsync("http://your api url");
responseTask.Wait();
if (responseTask.IsCompleted)
{
var result = responseTask.Result;
if (result.IsSuccessStatusCode)
{
var messageTask = result.Content.ReadAsStringAsync();
messageTask.Wait();
Console.WriteLine("Message from Web API:" + messageTask.Result);
Console.ReadLine();
}
}
}
i am trying to call the Zoom Api for Access token. It work Perfectly fine when i am trying to post with postman .
but from code it does not respond
ZoomApiLink_StepNo2
below are the following details
public static async Task<String> PostTogetToken<T>(string requestUrl, string client_Secretkey) {
ZoomToken hello = new ZoomToken();
var EncodedURl = ApiService.Base64Encode(client_Secretkey);
using (var _httpClient = new HttpClient()) {
if (!string.IsNullOrEmpty(requestUrl))
_httpClient.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", "Basic " + EncodedURl);
var httpContent = new StringContent("", System.Text.Encoding.UTF8, "application/x-www-form-urlencoded");
var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, new Uri(requestUrl)) {
Version = HttpVersion.Version11,
Content = httpContent
};
using (var response = await _httpClient.SendAsync(httpRequestMessage)) {
if (response.IsSuccessStatusCode) {
response.EnsureSuccessStatusCode();
return await response.Content.ReadAsStringAsync();
} else {
return await response.Content.ReadAsStringAsync();
}
}
}
}
You're seeing a common deadlock problem because code further up the stack is using Result, blocking on asynchronous code.
To fix, change the Result to await and use async all the way.
I'm trying to access a rest endpoint, https://api.planet.com/auth/v1/experimental/public/users/authenticate. It is expecting json in the request body.
I can get the request to work in Postman but not using c#. Using postman I get the expected invalid email or password message but with my code I get "Bad Request" no matter I try.
Here is the code that makes the request
private void Login()
{
try
{
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("https://api.planet.com/");
client.DefaultRequestHeaders.Accept.Clear();
//ClientDefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("*/*"));
Data.User user = new Data.User
{
email = "myemail#company.com",
password = "sdosadf"
};
var requestMessage = JsonConvert.SerializeObject(user);
var content = new StringContent(requestMessage, Encoding.UTF8, "application/json");
var response = client.PostAsync("auth/v1/experimental/public/users/authenticate", content).Result;
Console.WriteLine(response.ToString());
}
catch (WebException wex )
{
MessageBox.Show(wex.Message) ;
}
}
class User
{
public string email;
public string password;
}
Here are screen grabs form Postman that are working
The way to get this to work was to alter the content header "content-type". By default HTTPClient was creating content-type: application/json;characterset= UTF8. I dropped and recreated the content header without the characterset section and it worked.
content.Headers.Remove("Content-Type");
content.Headers.Add("Content-Type", "application/json");
The issue is you are trying to call an async method without waiting for the response using await method or var task = method; task.Wait() Therefore, when you end up doing response.ToString() it returns the text you are seeing.
One way to handle this within a non-async method would be to do the following:
var task = client.PostAsync("auth/v1/experimental/public/users/authenticate", content);
task.Wait();
var responseTask = task.Content.ReadAsStringAsync();
responseTask.Wait();
Console.WriteLine(responseTask.Result);
Another way is to make the current method async by doing private async void Login() and then do:
var postResp = await client.PostAsync("auth/v1/experimental/public/users/authenticate", content);
var response = await postResp.Content.ReadAsStringAsync();
Console.WriteLine(response);
Create a Method Like this...
static async Task<string> PostURI(Uri u, HttpContent c)
{
var response = string.Empty;
var msg = "";
using (var client = new HttpClient())
{
HttpResponseMessage result = await client.PostAsync(u, c);
msg = await result.Content.ReadAsStringAsync();
if (result.IsSuccessStatusCode)
{
response = result.StatusCode.ToString();
}
}
return response;
}
call In your Method
public void Login()
{
string postData ="{\"email\":\"your_email\",\"password\":\"your_password\"}";
Uri u = new Uri("yoururl");
var payload = postData;
HttpContent c = new StringContent(payload, Encoding.UTF8,"application/json");
var t = Task.Run(() => PostURI(u, c));
t.Wait();
Response.Write(t.Result);
}
I have a problem post string to form and read. Problem is they get away but need to do so sophisticated and it was very fast. Absolutely perfect multithreaded or asynchronous. Thank you very for your help.
This is my code.
private static void AsyncDown()
{
const string url = "http://whois.sk-nic.sk/index.jsp";
const string req = "PREM-0001";
var client = new HttpClient();
var pairs = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("text", "PREM-0001")
};
FormUrlEncodedContent content = new FormUrlEncodedContent(pairs);
HttpResponseMessage response = client.PostAsync("http://whois.sk-nic.sk/index.jsp", content).Result;
if (response.IsSuccessStatusCode)
{
HttpContent stream = response.Content;
Task<string> data = stream.ReadAsStringAsync();
}
}
Taking a rough stab in the dark at what your problem is, I'd guess that you're having trouble reading the response of your call.
When the content is POSTed to the server,
HttpResponseMessage response
= client.PostAsync("http://whois.sk-nic.sk/index.jsp", content).Result;
if (response.IsSuccessStatusCode)
{
HttpContent stream = response.Content;
Task<string> data = stream.ReadAsStringAsync();
}
It does so asynchronously, so the code will continue execution even though the result is not (most likely) available yet. Checking response.IsSuccessStatusCode will thus not give you the behavior you're expecting.
Change your calls to look like this by adding the await keyword:
HttpResponseMessage response
= await client.PostAsync("http://whois.sk-nic.sk/index.jsp", content);
Then, change the reading of the stream to use await as well:
if (response.IsSuccessStatusCode)
{
var data = await response.Content.ReadAsStringAsync();
}
EDIT: got some await objects mixed up and have corrected the code listing.
edit 2: here is the complete LINQPad script that I used to successfully download an HTML page from the given URL.
var client = new HttpClient();
var pairs = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("text", "PREM-0001")
};
FormUrlEncodedContent content = new FormUrlEncodedContent(pairs);
HttpResponseMessage response = await client.PostAsync("http://whois.sk-nic.sk/index.jsp", content);
if (response.IsSuccessStatusCode)
{
var data = await response.Content.ReadAsStringAsync();
//data.Dump(); //uncomment previous if using LINQPad
}
Maybe the site has changed since last post but now the request parameter name is whois not text. If this was the case a year ago too that's why it didn't work.
Today site responds to get too, i.e. http://whois.sk-nic.sk/index.jsp?whois=PREM-0001
Full code with get:
private async Task<string> Get(string code)
{
using (var client = new HttpClient())
{
var requestUri = String.Format("http://whois.sk-nic.sk/index.jsp?whois={0}", code);
var data = await client.GetStringAsync(requestUri);
return data;
}
}
Full code with post:
private async Task<string> Post()
{
using (var client = new HttpClient())
{
var postData = new KeyValuePair<string, string>[]
{
new KeyValuePair<string, string>("whois", "PREM-0001"),
};
var content = new FormUrlEncodedContent(postData);
var response = await client.PostAsync("http://whois.sk-nic.sk/index.jsp", content);
if (!response.IsSuccessStatusCode)
{
var message = String.Format("Server returned HTTP error {0}: {1}.", (int)response.StatusCode, response.ReasonPhrase);
throw new InvalidOperationException(message);
}
var data = await response.Content.ReadAsStringAsync();
return data;
}
}
Or a parser could be used because I guess extracting the returned values is the final goal:
private void HtmlAgilityPack(string code)
{
var requestUri = String.Format("http://whois.sk-nic.sk/index.jsp?whois={0}", code);
var request = new HtmlWeb();
var htmlDocument = request.Load(requestUri);
var name = htmlDocument.DocumentNode.SelectSingleNode("/html/body/table[1]/tr[5]/td/table/tr[2]/td[2]").InnerText.Trim();
var organizations = htmlDocument.DocumentNode.SelectSingleNode("/html/body/table[1]/tr[5]/td/table/tr[3]/td[2]").InnerText.Trim();
}