This is the code I have so far:
public class Class1
{
private const string URL = "https://sub.domain.com/objects.json?api_key=123";
private const string DATA = #"{""object"":{""name"":""Name""}}";
static void Main(string[] args)
{
Class1.CreateObject();
}
private static void CreateObject()
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
request.Method = "POST";
request.ContentType = "application/json";
request.ContentLength = DATA.Length;
StreamWriter requestWriter = new StreamWriter(request.GetRequestStream(), System.Text.Encoding.ASCII);
requestWriter.Write(DATA);
requestWriter.Close();
try {
WebResponse webResponse = request.GetResponse();
Stream webStream = webResponse.GetResponseStream();
StreamReader responseReader = new StreamReader(webStream);
string response = responseReader.ReadToEnd();
Console.Out.WriteLine(response);
responseReader.Close();
} catch (Exception e) {
Console.Out.WriteLine("-----------------");
Console.Out.WriteLine(e.Message);
}
}
}
The problem is that I think the exception block is being triggered (because when I remove the try-catch, I get a server error (500) message. But I don't see the Console.Out lines I put in the catch block.
My Console:
The thread 'vshost.NotifyLoad' (0x1a20) has exited with code 0 (0x0).
The thread '<No Name>' (0x1988) has exited with code 0 (0x0).
The thread 'vshost.LoadReference' (0x1710) has exited with code 0 (0x0).
'ConsoleApplication1.vshost.exe' (Managed (v4.0.30319)): Loaded 'c:\users\l. preston sego iii\documents\visual studio 11\Projects\ConsoleApplication1\ConsoleApplication1\bin\Debug\ConsoleApplication1.exe', Symbols loaded.
'ConsoleApplication1.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Configuration\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
A first chance exception of type 'System.Net.WebException' occurred in System.dll
The thread 'vshost.RunParkingWindow' (0x184c) has exited with code 0 (0x0).
The thread '<No Name>' (0x1810) has exited with code 0 (0x0).
The program '[2780] ConsoleApplication1.vshost.exe: Program Trace' has exited with code 0 (0x0).
The program '[2780] ConsoleApplication1.vshost.exe: Managed (v4.0.30319)' has exited with code 0 (0x0).
The ASP.NET Web API has replaced the WCF Web API previously mentioned.
I thought I'd post an updated answer since most of these responses are from early 2012, and this thread is one of the top results when doing a Google search for "call restful service C#".
Current guidance from Microsoft is to use the Microsoft ASP.NET Web API Client Libraries to consume a RESTful service. This is available as a NuGet package, Microsoft.AspNet.WebApi.Client. You will need to add this NuGet package to your solution.
Here's how your example would look when implemented using the ASP.NET Web API Client Library:
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
namespace ConsoleProgram
{
public class DataObject
{
public string Name { get; set; }
}
public class Class1
{
private const string URL = "https://sub.domain.com/objects.json";
private string urlParameters = "?api_key=123";
static void Main(string[] args)
{
HttpClient client = new HttpClient();
client.BaseAddress = new Uri(URL);
// Add an Accept header for JSON format.
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
// List data response.
HttpResponseMessage response = client.GetAsync(urlParameters).Result; // Blocking call! Program will wait here until a response is received or a timeout occurs.
if (response.IsSuccessStatusCode)
{
// Parse the response body.
var dataObjects = response.Content.ReadAsAsync<IEnumerable<DataObject>>().Result; //Make sure to add a reference to System.Net.Http.Formatting.dll
foreach (var d in dataObjects)
{
Console.WriteLine("{0}", d.Name);
}
}
else
{
Console.WriteLine("{0} ({1})", (int)response.StatusCode, response.ReasonPhrase);
}
// Make any other calls using HttpClient here.
// Dispose once all HttpClient calls are complete. This is not necessary if the containing object will be disposed of; for example in this case the HttpClient instance will be disposed automatically when the application terminates so the following call is superfluous.
client.Dispose();
}
}
}
If you plan on making multiple requests, you should re-use your HttpClient instance. See this question and its answers for more details on why a using statement was not used on the HttpClient instance in this case: Do HttpClient and HttpClientHandler have to be disposed between requests?
For more details, including other examples, see Call a Web API From a .NET Client (C#)
This blog post may also be useful: Using HttpClient to Consume ASP.NET Web API REST Services
My suggestion would be to use RestSharp. You can make calls to REST services and have them cast into POCO objects with very little boilerplate code to actually have to parse through the response. This will not solve your particular error, but it answers your overall question of how to make calls to REST services. Having to change your code to use it should pay off in the ease of use and robustness moving forward. That is just my two cents though.
Example:
namespace RestSharpThingy
{
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Reflection;
using RestSharp;
public static class Program
{
public static void Main()
{
Uri baseUrl = new Uri("https://httpbin.org/");
IRestClient client = new RestClient(baseUrl);
IRestRequest request = new RestRequest("get", Method.GET) { Credentials = new NetworkCredential("testUser", "P455w0rd") };
request.AddHeader("Authorization", "Bearer qaPmk9Vw8o7r7UOiX-3b-8Z_6r3w0Iu2pecwJ3x7CngjPp2fN3c61Q_5VU3y0rc-vPpkTKuaOI2eRs3bMyA5ucKKzY1thMFoM0wjnReEYeMGyq3JfZ-OIko1if3NmIj79ZSpNotLL2734ts2jGBjw8-uUgKet7jQAaq-qf5aIDwzUo0bnGosEj_UkFxiJKXPPlF2L4iNJSlBqRYrhw08RK1SzB4tf18Airb80WVy1Kewx2NGq5zCC-SCzvJW-mlOtjIDBAQ5intqaRkwRaSyjJ_MagxJF_CLc4BNUYC3hC2ejQDoTE6HYMWMcg0mbyWghMFpOw3gqyfAGjr6LPJcIly__aJ5__iyt-BTkOnMpDAZLTjzx4qDHMPWeND-TlzKWXjVb5yMv5Q6Jg6UmETWbuxyTdvGTJFzanUg1HWzPr7gSs6GLEv9VDTMiC8a5sNcGyLcHBIJo8mErrZrIssHvbT8ZUPWtyJaujKvdgazqsrad9CO3iRsZWQJ3lpvdQwucCsyjoRVoj_mXYhz3JK3wfOjLff16Gy1NLbj4gmOhBBRb8rJnUXnP7rBHs00FAk59BIpKLIPIyMgYBApDCut8V55AgXtGs4MgFFiJKbuaKxq8cdMYEVBTzDJ-S1IR5d6eiTGusD5aFlUkAs9NV_nFw");
request.AddParameter("clientId", 123);
IRestResponse<RootObject> response = client.Execute<RootObject>(request);
if (response.IsSuccessful)
{
response.Data.Write();
}
else
{
Console.WriteLine(response.ErrorMessage);
}
Console.WriteLine();
string path = Assembly.GetExecutingAssembly().Location;
string name = Path.GetFileName(path);
request = new RestRequest("post", Method.POST);
request.AddFile(name, File.ReadAllBytes(path), name, "application/octet-stream");
response = client.Execute<RootObject>(request);
if (response.IsSuccessful)
{
response.Data.Write();
}
else
{
Console.WriteLine(response.ErrorMessage);
}
Console.ReadLine();
}
private static void Write(this RootObject rootObject)
{
Console.WriteLine("clientId: " + rootObject.args.clientId);
Console.WriteLine("Accept: " + rootObject.headers.Accept);
Console.WriteLine("AcceptEncoding: " + rootObject.headers.AcceptEncoding);
Console.WriteLine("AcceptLanguage: " + rootObject.headers.AcceptLanguage);
Console.WriteLine("Authorization: " + rootObject.headers.Authorization);
Console.WriteLine("Connection: " + rootObject.headers.Connection);
Console.WriteLine("Dnt: " + rootObject.headers.Dnt);
Console.WriteLine("Host: " + rootObject.headers.Host);
Console.WriteLine("Origin: " + rootObject.headers.Origin);
Console.WriteLine("Referer: " + rootObject.headers.Referer);
Console.WriteLine("UserAgent: " + rootObject.headers.UserAgent);
Console.WriteLine("origin: " + rootObject.origin);
Console.WriteLine("url: " + rootObject.url);
Console.WriteLine("data: " + rootObject.data);
Console.WriteLine("files: ");
foreach (KeyValuePair<string, string> kvp in rootObject.files ?? Enumerable.Empty<KeyValuePair<string, string>>())
{
Console.WriteLine("\t" + kvp.Key + ": " + kvp.Value);
}
}
}
public class Args
{
public string ClientId { get; set; }
}
public class Headers
{
public string Accept { get; set; }
public string AcceptEncoding { get; set; }
public string AcceptLanguage { get; set; }
public string Authorization { get; set; }
public string Connection { get; set; }
public string Dnt { get; set; }
public string Host { get; set; }
public string Origin { get; set; }
public string Referer { get; set; }
public string UserAgent { get; set; }
}
public class RootObject
{
public Args args { get; set; }
public Headers Headers { get; set; }
public string Origin { get; set; }
public string Url { get; set; }
public string Data { get; set; }
public Dictionary<string, string> Files { get; set; }
}
}
Unrelated, I'm sure, but do wrap your IDisposable objects in using blocks to ensure proper disposal:
using System;
using System.Net;
using System.IO;
namespace ConsoleProgram
{
public class Class1
{
private const string URL = "https://sub.domain.com/objects.json?api_key=123";
private const string DATA = #"{""object"":{""name"":""Name""}}";
static void Main(string[] args)
{
Class1.CreateObject();
}
private static void CreateObject()
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
request.Method = "POST";
request.ContentType = "application/json";
request.ContentLength = DATA.Length;
using (Stream webStream = request.GetRequestStream())
using (StreamWriter requestWriter = new StreamWriter(webStream, System.Text.Encoding.ASCII))
{
requestWriter.Write(DATA);
}
try
{
WebResponse webResponse = request.GetResponse();
using (Stream webStream = webResponse.GetResponseStream() ?? Stream.Null)
using (StreamReader responseReader = new StreamReader(webStream))
{
string response = responseReader.ReadToEnd();
Console.Out.WriteLine(response);
}
}
catch (Exception e)
{
Console.Out.WriteLine("-----------------");
Console.Out.WriteLine(e.Message);
}
}
}
}
Here are a few different ways of calling an external API in C# (updated 2019).
.NET's built-in ways:
WebRequest& WebClient - verbose APIs & Microsoft's documentation is not very easy to follow
HttpClient - .NET's newest kid on the block & much simpler to use than above.
Free, open-source NuGet Packages, which frankly have a much better developer experience than .NET's built in clients:
ServiceStack.Text (1,000 GitHub stars, 7 million NuGet downloads) (*) - fast, light and resilient.
RestSharp (6,000 GitHub stars, 23 million NuGet downloads) (*) - simple REST and HTTP API Client
Flurl (1,700 GitHub stars, 3 million NuGet downloads) (*)- a fluent, portable, testable HTTP client library
All the above packages provide a great developer experience (i.e., concise, easy API) and are well maintained.
(*) as at August 2019
Example: Getting a Todo item from a Fake Rest API using ServiceStack.Text.
The other libraries have very similar syntax.
class Program
{
static void Main(string[] args)
{
// Fake rest API
string url = "https://jsonplaceholder.typicode.com/todos/1";
// GET data from API & map to POCO
var todo = url.GetJsonFromUrl().FromJson<Todo>();
// Print the result to screen
todo.PrintDump();
}
public class Todo
{
public int UserId { get; set; }
public int Id { get; set; }
public string Title { get; set; }
public bool Completed { get; set; }
}
}
Running the above example in a .NET Core Console app, produces the following output.
Install these packages using NuGet
Install-Package ServiceStack.Text, or
Install-Package RestSharp, or
Install-Package Flurl.Http
A solution in ASP.NET Core:
using Newtonsoft.Json;
using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;
namespace WebApp
{
public static class HttpHelper
{
// In my case this is https://localhost:44366/
private static readonly string apiBasicUri = ConfigurationManager.AppSettings["apiBasicUri"];
public static async Task Post<T>(string url, T contentValue)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(apiBasicUri);
var content = new StringContent(JsonConvert.SerializeObject(contentValue), Encoding.UTF8, "application/json");
var result = await client.PostAsync(url, content);
result.EnsureSuccessStatusCode();
}
}
public static async Task Put<T>(string url, T stringValue)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(apiBasicUri);
var content = new StringContent(JsonConvert.SerializeObject(stringValue), Encoding.UTF8, "application/json");
var result = await client.PutAsync(url, content);
result.EnsureSuccessStatusCode();
}
}
public static async Task<T> Get<T>(string url)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(apiBasicUri);
var result = await client.GetAsync(url);
result.EnsureSuccessStatusCode();
string resultContentString = await result.Content.ReadAsStringAsync();
T resultContent = JsonConvert.DeserializeObject<T>(resultContentString);
return resultContent;
}
}
public static async Task Delete(string url)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(apiBasicUri);
var result = await client.DeleteAsync(url);
result.EnsureSuccessStatusCode();
}
}
}
}
To post, use something like this:
await HttpHelper.Post<Setting>($"/api/values/{id}", setting);
Example for delete:
await HttpHelper.Delete($"/api/values/{id}");
Example to get a list:
List<ClaimTerm> claimTerms = await HttpHelper.Get<List<ClaimTerm>>("/api/values/");
Example to get only one:
ClaimTerm processedClaimImage = await HttpHelper.Get<ClaimTerm>($"/api/values/{id}");
Please use the below code for your REST API request:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Json;
namespace ConsoleApplication2
{
class Program
{
private const string URL = "https://XXXX/rest/api/2/component";
private const string DATA = #"{
""name"": ""Component 2"",
""description"": ""This is a JIRA component"",
""leadUserName"": ""xx"",
""assigneeType"": ""PROJECT_LEAD"",
""isAssigneeTypeValid"": false,
""project"": ""TP""}";
static void Main(string[] args)
{
AddComponent();
}
private static void AddComponent()
{
System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
client.BaseAddress = new System.Uri(URL);
byte[] cred = UTF8Encoding.UTF8.GetBytes("username:password");
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", Convert.ToBase64String(cred));
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
System.Net.Http.HttpContent content = new StringContent(DATA, UTF8Encoding.UTF8, "application/json");
HttpResponseMessage messge = client.PostAsync(URL, content).Result;
string description = string.Empty;
if (messge.IsSuccessStatusCode)
{
string result = messge.Content.ReadAsStringAsync().Result;
description = result;
}
}
}
}
Calling a REST API when using .NET 4.5 or .NET Core
I would suggest DalSoft.RestClient (caveat: I created it). The reason being, because it uses dynamic typing, you can wrap everything up in one fluent call including serialization/de-serialization. Below is a working PUT example:
dynamic client = new RestClient("http://jsonplaceholder.typicode.com");
var post = new Post { title = "foo", body = "bar", userId = 10 };
var result = await client.Posts(1).Put(post);
GET:
// GET JSON Response
public WeatherResponseModel GET(string url) {
WeatherResponseModel model = new WeatherResponseModel();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
try {
WebResponse response = request.GetResponse();
using(Stream responseStream = response.GetResponseStream()) {
StreamReader reader = new StreamReader(responseStream, Encoding.UTF8);
model = JsonConvert.DeserializeObject < WeatherResponseModel > (reader.ReadToEnd());
}
} catch (WebException ex) {
WebResponse errorResponse = ex.Response;
using(Stream responseStream = errorResponse.GetResponseStream()) {
StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
String errorText = reader.ReadToEnd();
// Log errorText
}
throw;
}
return model;
}
POST:
// POST a JSON string
void POST(string url, string jsonContent) {
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "POST";
System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
Byte[]byteArray = encoding.GetBytes(jsonContent);
request.ContentLength = byteArray.Length;
request.ContentType = # "application/json";
using(Stream dataStream = request.GetRequestStream()) {
dataStream.Write(byteArray, 0, byteArray.Length);
}
long length = 0;
try {
using(HttpWebResponse response = (HttpWebResponse)request.GetResponse()) {
// Got response
length = response.ContentLength;
}
} catch (WebException ex) {
WebResponse errorResponse = ex.Response;
using(Stream responseStream = errorResponse.GetResponseStream()) {
StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
String errorText = reader.ReadToEnd();
// Log errorText
}
throw;
}
}
Note: To serialize and desirialze JSON, I used the Newtonsoft.Json NuGet package.
Check out Refit for making calls to REST services from .NET. I've found it very easy to use:
Refit: The automatic type-safe REST library for .NET Core, Xamarin and
.NET
Refit is a library heavily inspired by Square's Retrofit library, and
it turns your REST API into a live interface:
public interface IGitHubApi {
[Get("/users/{user}")]
Task<User> GetUser(string user);
}
// The RestService class generates an implementation of IGitHubApi
// that uses HttpClient to make its calls:
var gitHubApi = RestService.For<IGitHubApi>("https://api.github.com");
var octocat = await gitHubApi.GetUser("octocat");
This is example code that works for sure. It took me a day to make this to read a set of objects from a REST service:
RootObject is the type of the object I'm reading from the REST service.
string url = #"http://restcountries.eu/rest/v1";
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(IEnumerable<RootObject>));
WebClient syncClient = new WebClient();
string content = syncClient.DownloadString(url);
using (MemoryStream memo = new MemoryStream(Encoding.Unicode.GetBytes(content)))
{
IEnumerable<RootObject> countries = (IEnumerable<RootObject>)serializer.ReadObject(memo);
}
Console.Read();
I did it in this simple way, with Web API 2.0. You can remove UseDefaultCredentials. I used it for my own use cases.
List<YourObject> listObjects = new List<YourObject>();
string response = "";
using (var client = new WebClient() { UseDefaultCredentials = true })
{
response = client.DownloadString(apiUrl);
}
listObjects = JsonConvert.DeserializeObject<List<YourObject>>(response);
return listObjects;
var TakingRequset = WebRequest.Create("http://xxx.acv.com/MethodName/Get");
TakingRequset.Method = "POST";
TakingRequset.ContentType = "text/xml;charset=utf-8";
TakingRequset.PreAuthenticate = true;
//---Serving Request path query
var PAQ = TakingRequset.RequestUri.PathAndQuery;
//---creating your xml as per the host reqirement
string xmlroot=#"<root><childnodes>passing parameters</childnodes></root>";
string xmlroot2=#"<root><childnodes>passing parameters</childnodes></root>";
//---Adding Headers as requested by host
xmlroot2 = (xmlroot2 + "XXX---");
//---Adding Headers Value as requested by host
// var RequestheaderVales = Method(xmlroot2);
WebProxy proxy = new WebProxy("XXXXX-----llll", 8080);
proxy.Credentials = new NetworkCredential("XXX---uuuu", "XXX----", "XXXX----");
System.Net.WebRequest.DefaultWebProxy = proxy;
// Adding The Request into Headers
TakingRequset.Headers.Add("xxx", "Any Request Variable ");
TakingRequset.Headers.Add("xxx", "Any Request Variable");
byte[] byteData = Encoding.UTF8.GetBytes(xmlroot);
TakingRequset.ContentLength = byteData.Length;
using (Stream postStream = TakingRequset.GetRequestStream())
{
postStream.Write(byteData, 0, byteData.Length);
postStream.Close();
}
StreamReader stredr = new StreamReader(TakingRequset.GetResponse().GetResponseStream());
string response = stredr.ReadToEnd();
The answer marked here suggests using HttpClient directly and the disposing of it. This might work, but it's quite easy to run in to problems with HttpClient if you don't use it correctly.
If you're going to use HttpClient, you're better off handing over the creation/disposal of HttpClients to a third-party library that uses the factory pattern. RestClient.Net is one such library.
It comes with a very basic HttpClient factory so that you don't run in to the socket exhaustion problem,
public class DefaultHttpClientFactory : IHttpClientFactory, IDisposable
{
#region Fields
private bool disposed;
private readonly ConcurrentDictionary<string, Lazy<HttpClient>> _httpClients;
private readonly Func<string, Lazy<HttpClient>> _createClientFunc;
#endregion
#region Constructor
public DefaultHttpClientFactory() : this(null)
{
}
public DefaultHttpClientFactory(Func<string, Lazy<HttpClient>> createClientFunc)
{
_createClientFunc = createClientFunc;
_httpClients = new ConcurrentDictionary<string, Lazy<HttpClient>>();
if (_createClientFunc != null) return;
_createClientFunc = name =>
{
return new Lazy<HttpClient>(() => new HttpClient(), LazyThreadSafetyMode.ExecutionAndPublication);
};
}
#endregion
#region Implementation
public HttpClient CreateClient(string name)
{
if (name == null)
{
throw new ArgumentNullException(nameof(name));
}
return _httpClients.GetOrAdd(name, _createClientFunc).Value;
}
public void Dispose()
{
if (disposed) return;
disposed = true;
foreach (var name in _httpClients.Keys)
{
_httpClients[name].Value.Dispose();
}
}
#endregion
}
But Microsoft's IHttpClientFactory implementation can also be used for the latest and greatest:
var serviceCollection = new ServiceCollection();
var baseUri = new Uri("http://www.test.com");
serviceCollection.AddSingleton(typeof(ISerializationAdapter), typeof(NewtonsoftSerializationAdapter));
serviceCollection.AddSingleton(typeof(ILogger), typeof(ConsoleLogger));
serviceCollection.AddSingleton(typeof(IClient), typeof(Client));
serviceCollection.AddDependencyInjectionMapping();
serviceCollection.AddTransient<TestHandler>();
//Make sure the HttpClient is named the same as the Rest Client
serviceCollection.AddSingleton<IClient>(x => new Client(name: clientName, httpClientFactory: x.GetRequiredService<IHttpClientFactory>()));
serviceCollection.AddHttpClient(clientName, (c) => { c.BaseAddress = baseUri; })
.AddHttpMessageHandler<TestHandler>();
var serviceProvider = serviceCollection.BuildServiceProvider();
var client = serviceProvider.GetService<IClient>();
await client.GetAsync<object>();
RestClient.Net takes in to account dependency injection, mocking, IoC containers, unit testability, and above all is fast. I've hunted around and the only the other client that seems to work in a similar capacity is Flurl.Http.
We have started using speakeasy. It is great:
https://github.com/jonnii/SpeakEasy
// create a client
var client = HttpClient.Create("http://example.com/api");
// get some companies!
var companies = client.Get("companies").OnOk().As<List<Company>>();
// upload a company, with validation error support
client.Post(company, "companies")
.On(HttpStatusCode.BadRequest, (List<ValidationError> errors) => {
Console.WriteLine("Ruh Roh, you have {0} validation errors", errors.Count());
})
.On(HttpStatusCode.Created, () => Console.WriteLine("Holy moly you win!"));
// update a company
client.Put(company, "company/:id", new { id = "awesome-sauce" })
.OnOk(() => Console.WriteLine("Company updated"));
// run a search
client.Get("images/:category", new { category = "cats", breed = "omg the cutest", size = "kittens" })
.OnOk().As<List<Image>>();
// make an asynchronous request
var response = await client.GetAsync("companies/:id", new { id = 5 })
response.OnOk(UpdateCompaniesCallback)
Since you are using Visual Studio 11 Beta, you will want to use the latest and greatest. The new Web API contains classes for this.
See HttpClient: http://wcf.codeplex.com/wikipage?title=WCF%20HTTP
HTTP GET Request
string api = this.configuration["getApiUrl"];//Read from Iconfiguration object injected
public async Task<HttpResponseMessage> GetAsync(string api, ILogger log, params dynamic[] parameters)
{
log.LogInformation($"Get Token");
var token = await GetTokenAsync(this.configuration["ClientId"], this.configuration["AppKey"]).ConfigureAwait(false);
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(BearerTokenName, token);
var apiBaseUrl = this.configuration["BaseUrl"];
client.BaseAddress = new Uri(apiBaseUrl);
var apiUrl = ConstructUrl(api, parameters);
var result = await client.GetAsync(apiUrl).ConfigureAwait(false);
if (result.StatusCode == System.Net.HttpStatusCode.OK)
{
return result;
}
else
{
throw new HttpResponseException(new HttpResponseMessage(result.StatusCode) { Content = new StringContent(result.ReasonPhrase) });
}
}
}
Read String from HttpResponseMessage as below
var client = await this.httpClientService.GetAsync(url, logger, Convert.ToInt32(Id, CultureInfo.InvariantCulture)).ConfigureAwait(false);
var response = await client.Content.ReadAsStringAsync();
HTTP POST Request
public async Task<string> PostAsync(string api, string contentValue, ILogger logger)
{
var token = await GetTokenAsync(this.configuration["ClientId"], this.configuration["AppKey"]).ConfigureAwait(false);
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(BearerTokenName, token);
client.BaseAddress = new Uri(resource);
var content = new StringContent(contentValue, Encoding.UTF8, MediaTypeNames.Application.Json);
var result = await client.PostAsync(new Uri(api, UriKind.Relative), content).ConfigureAwait(false);
if (result.StatusCode == System.Net.HttpStatusCode.OK)
{
return await result.Content.ReadAsStringAsync();
}
else
{
throw new HttpResponseException(new HttpResponseMessage(result.StatusCode) { Content = new StringContent(result.ReasonPhrase) });
}
}
}
var response = await this.httpClientService.PostAsync(this.configuration["getDetails"], content, this.configuration["ApiBaseUrl"], logger).ConfigureAwait(false);
catch (System.Web.Http.HttpResponseException httpException)
{
if (httpException.Response.StatusCode == HttpStatusCode.Unauthorized)
{
logger.LogError($"Failed To Update", httpException);
}
else
{
throw;
}
}
return response;
The first step is to create the helper class for the HTTP client.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
namespace callApi.Helpers
{
public class CallApi
{
private readonly Uri BaseUrlUri;
private HttpClient client = new HttpClient();
public CallApi(string baseUrl)
{
BaseUrlUri = new Uri(baseUrl);
client.BaseAddress = BaseUrlUri;
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
}
public HttpClient getClient()
{
return client;
}
public HttpClient getClientWithBearer(string token)
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
return client;
}
}
}
Then you can use this class in your code.
This is an example of how you call the REST API without bearer using the above class.
// GET API/values
[HttpGet]
public async Task<ActionResult<string>> postNoBearerAsync(string email, string password,string baseUrl, string action)
{
var request = new LoginRequest
{
email = email,
password = password
};
var callApi = new CallApi(baseUrl);
var client = callApi.getClient();
HttpResponseMessage response = await client.PostAsJsonAsync(action, request);
if (response.IsSuccessStatusCode)
return Ok(await response.Content.ReadAsAsync<string>());
else
return NotFound();
}
This is an example of how you can call the REST API that require bearer.
// GET API/values
[HttpGet]
public async Task<ActionResult<string>> getUseBearerAsync(string token, string baseUrl, string action)
{
var callApi = new CallApi(baseUrl);
var client = callApi.getClient();
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
HttpResponseMessage response = await client.GetAsync(action);
if (response.IsSuccessStatusCode)
{
return Ok(await response.Content.ReadAsStringAsync());
}
else
return NotFound();
}
You can also refer to the below repository if you want to see the working example of how it works.
https://github.com/mokh223/callApi
Related
I have to create a client application to connect to an API to post and get information,
the information that I got from the company who have the API is:
API details for: xxxxx
Integration: yyyyxxxx
API URL: https://api.xyz.us/v123/
APP KEY: xxxxx12312xxxxx2123123xxxxx
SECRET KEY: 11111111111111111xxxxxxxxxxx
I want to use c# or other language to create the client, I couldn't find any c# sample for desktop application, I found a c# console basic sample, It's like no one use APIs with c#,
Is there any sample for a client to connect to an API using C# Desktop application?
or what can I use to accomplish this task?
Thanks
Here's HttpClient example based on the snippet from OP's answer
using System.Threading.Tasks;
using System.Net.Http;
using System.Text;
using System.Net.Http.Headers;
public class RESTClient
{
private readonly HttpClient client = new HttpClient();
public RESTClient(string baseAddress)
{
client.BaseAddress = new Uri(baseAddress);
}
public void SetAuthHeader(string parameter)
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", parameter);
}
public async Task<string> MakeRequestAsync(HttpMethod method, string path, string postContent = "")
{
try
{
using (HttpContent content = new StringContent(postContent, Encoding.UTF8, "application/json"))
using (HttpRequestMessage request = new HttpRequestMessage(method, path))
{
if (method == HttpMethod.Post || method == HttpMethod.Put) request.Content = content;
using (HttpResponseMessage response = await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false))
{
response.EnsureSuccessStatusCode();
return await response.Content.ReadAsStringAsync().ConfigureAwait(false);
}
}
}
catch (Exception ex)
{
return "{\"errorMessages\":[\"" + ex.Message + "\"],\"errors\":{}}";
}
}
}
Usage example (WinForms)
private RESTClient restClient;
private void Form1_Load(object sender, EventArgs e)
{
restClient = new RESTClient("https://myapi.url/api");
restClient.SetAuthHeader("iODA0NjMxMTgwMWUzYWFkYTk4NjM2MjcyOTk3MDowYTU0N2I2NzliNWRkMjliN2I4NTFlMDBkY2Y2NjQzNzQ5OTIxYzZl");
}
private async void button1_Click(object sender, EventArgs e)
{
// GET
string getJsonResult = await restClient.MakeRequestAsync(HttpMethod.Get, "path/to/method");
// POST
string postJsonResult = await restClient.MakeRequestAsync(HttpMethod.Post, "path/to/method", "{\"data\": \"Some Request Data\"}");
// process data here
}
Thanks to everyone who help. I found the answer on Postman,
first I found a C# desktop client application sample.
the problem with this sample is that it didn't use an API key and secret key.
I found many answers on how to add the API key and secret key
but the one worked was the one on Postman, in the section 'code'
request.Headers["Authorization"] = "Basic ZmRiODA0NjMxMTgwMWUzYWFkYTk4NjM2MjcyOTk3MDowYTU0N2I2NzliNWRkMjliN2I4NTFlMDBkY2Y2NjQzNzQ5OTIxYzZl";
the complete c# code is:
using System;
using System.IO;
using System.Net;
using System.Text;
namespace restClient_0
{
public enum httpVerb
{
GET,
POST,
PUT,
DELETE
}
class RESTClient
{
public string endPoint { get; set; }
public httpVerb httpMethod { get; set; }
public RESTClient()
{
endPoint = "";
httpMethod = httpVerb.GET;
}
public string makeRequest()
{
string strResponseValue = string.Empty;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(endPoint);
request.Method = httpMethod.ToString();
request.Headers["Authorization"] = "Basic iODA0NjMxMTgwMWUzYWFkYTk4NjM2MjcyOTk3MDowYTU0N2I2NzliNWRkMjliN2I4NTFlMDBkY2Y2NjQzNzQ5OTIxYzZl";
HttpWebResponse response = null;
try
{
response = (HttpWebResponse)request.GetResponse();
//Proecess the resppnse stream... (could be JSON, XML or HTML etc..._
using (Stream responseStream = response.GetResponseStream())
{
if (responseStream != null)
{
using (StreamReader reader = new StreamReader(responseStream))
{
strResponseValue = reader.ReadToEnd();
}
}
}
}
catch(Exception ex)
{
strResponseValue = "{\"errorMessages\":[\"" + ex.Message.ToString() + "\"],\"errors\":{}}";
}
finally
{
if (response != null)
{
((IDisposable)response).Dispose();
}
}
return strResponseValue;
}
}
}
I am currently trying to authenticate Graph API using my C#. I am able to query this API and receive the token successfully from Postman.But when I call same API, I get 404 error.
My code is as below:
using System;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using Newtonsoft.Json;
namespace GraphTest
{
public class AuthenticationModel
{
public string grantType { get; set; } = "client_credentials";
public string clientId { get; set; } = "my_ad_app_id";
public string clientSecret { get; set; } = "client_secret";
public string scope { get; set; } = "https://graph.microsoft.com/.default";
}
public class Authentication
{
private static string tenantId = "tenant_id";
private static readonly HttpClient Client = new HttpClient();
public Authentication()
{
var authenticationModel = new AuthenticationModel();
RunAsync().GetAwaiter().GetResult();
}
private static async Task RunAsync()
{
Client.BaseAddress = new Uri("https://login.microsoftonline.com/");
Client.DefaultRequestHeaders.Accept.Clear();
Client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("*/*"));
Client.DefaultRequestHeaders.Add("Host", "login.microsoftonline.com");
Client.DefaultRequestHeaders.Add("Cache-Control", "no-cache");
try
{
var authenticationModel = new AuthenticationModel();
var url = await GetTokenAsync(authenticationModel);
Console.WriteLine($"Created at {url}");
}
catch (Exception exception)
{
Console.WriteLine(exception.Message);
}
}
private static async Task<Uri> GetTokenAsync(AuthenticationModel authenticationModel)
{
var keyValues = authenticationModel.GetType().GetProperties()
.ToList()
.Select(p => $"{p.Name} = {p.GetValue(authenticationModel)}")
.ToArray();
var xUrlEncodedBody = string.Join('&', keyValues);
var response = await Client.PostAsJsonAsync(
$"{tenantId}/oauth2/v2.0/token", xUrlEncodedBody);
response.EnsureSuccessStatusCode();
return response;
}
}
}
So, I recieve this in response: StatusCode:404, ReasonPhrase:Not Found
Please help me in knowing that where I am doing it wrong.
Note: API with same data works fine with Postman. Though, I have replaced some values here for security reasons.
You should not post form URL encoded content as JSON (PostAsJsonAsync). The body needs to have a content type of application/x-www-form-urlencoded.
But backing up a second, you don't need to implement the protocol yourself when there are libraries out there that do it for you :). We provide and support the Microsoft Authentication Library (MSAL) which makes this easy.
var app = ConfidentialClientApplicationBuilder.Create(config.ClientId)
.WithTenantId("{tenantID}")
.WithClientSecret(config.ClientSecret)
.Build();
string[] scopes = new string[] { "https://graph.microsoft.com/.default" };
AuthenticationResult result = null;
try
{
result = await app.AcquireTokenForClient(scopes).ExecuteAsync();
}
catch (MsalServiceException ex)
{
Console.WriteLine($"Error getting token: {ex.Message}");
}
Console.WriteLine($"Token: {result.AccessToken}");
I ran your code and it is wrongly generating query string as below with spaces.
xUrlEncodedBody => grantType = client_credentials&clientId = my_ad_app_id&clientSecret = client_secret&scope = https://graph.microsoft.com/.default
There is space between query parameter name and value, see below line.
.Select(p => $"{p.Name} = {p.GetValue(authenticationModel)}")
Remove the space and try again
.Select(p => $"{p.Name}={p.GetValue(authenticationModel)}")
I am getting data from a web api by making httpclient calls from various MVC controllers. Because I have to do it many times, I made a generic method that I can reuse by just passing in the api url and the model return type. It works fine, but I am concerned I am loosing the oppurtunity to have different methods, like GetPeople, GetPersonById, etc. Is there a downside to what I am doing?
Utilities.cs:
public static T GetDataFromWebService<T>(T model, string svcEndPoint)
{
HttpClient client = new HttpClient(new HttpClientHandler() { UseDefaultCredentials = true });
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = client.GetAsync(svcEndPoint).Result;
var result = response.Content.ReadAsAsync<T>().Result;
return result;
}
Controller:
string svc = appSettings.GetPeopleApiUrl;
var model = new List<Person>();
var people = Utilities.GetDataFromWebService <IEnumerable<Person>>(model, svc);
You can still have specialized methods such as GetPeople, GetPersonById by layering them on top:
PeopleModel GetPeople(...) {
return GetDataFromWebService<PeopleModel>(...);
}
No downsides, it is good that you have all boilerplate code in a shared utility method.
Well, there is definitely, better way of doing the overall implementation, but if I have to stick to the question, I would say any attempt of reducing coupling is a good step for future directions. In your situation, since you are abstracting away the responsibility of making service calls to a utility method, it would help you in the long run.
Though I would suggest that instead of having this stuffed together in Utility class you should make the connectivity it's own class, something like this
public delegate T ParseToObject<T>(string response);
public class ServiceConnector : IServiceConnector
{
public string LogoffUrl { get; set; }
public bool SupportRetry { get; set; }
private WebClient _client;
public ServiceConnector()
{
}
public T GetResponse<T>(string requestUrl, ParseToObject<T> parsingMethod)
{
string response = __getResponse(requestUrl);
return parsingMethod(response);
}
private string __getResponse(string requestUrl)
{
string serviceResponse = string.Empty;
try
{
__initializeWebClient();
Logger.Current.LogInfo(string.Format("Sending request with URL {0}", requestUrl));
serviceResponse = _client.DownloadString(requestUrl);
}
catch (Exception ex)
{
if (ex.Message != null)
{
Logger.Current.LogException(string.Format("Exception during OvidWS request {0} ", requestUrl), ex);
_client = null;
}
//Sample implementation only, you could throw the exception up based on your domain needs
}
return serviceResponse;
}
private void __initializeWebClient()
{
if (_client == null)
_client = new WebClient();
}
}
With this in place, tomorrow, let's say you want to add support to log off, support cookies, support credentials, support retries, this is the only place where you can be and comfortably make changes. Similarly if you want to use Webclient over something else, you can also do that better here.
Try with that helper:
public static class WebClientExtension
{
public static T DownloadSerializedJsonData<T>(string url) where T : new()
{
var contentType = ConfigurationManager.AppSettings["ContentType"];//content type in app config or web config
using (var webClient = new WebClient())
{
webClient.Headers.Add("Content-Type", contentType);
var jsonData = string.Empty;
try
{
jsonData = webClient.DownloadString(url);
}
catch (Exception ex)
{
throw ex;
}
return !string.IsNullOrEmpty(jsonData) ? JsonConvert.DeserializeObject<T>(jsonData) : new T();
}
}
public static T AuthorizationContentSerializedJsonData<T>(string url) where T : new()
{
string jsonData = null;
try
{
var httpRequest = (HttpWebRequest)WebRequest.Create(url);
//ClientBase.AuthorizeRequest(httpRequest, Authorization.AccessToken);
var response = httpRequest.GetResponse();
Stream receiveStream = response.GetResponseStream();
var readStream = new StreamReader(receiveStream, Encoding.UTF8);
jsonData = readStream.ReadToEnd();
response.Close();
}
catch (Exception ex)
{
throw ex;
}
return !string.IsNullOrEmpty(jsonData) ? JsonConvert.DeserializeObject<T>(jsonData) : new T();
}
}
App confing / Web config example for content type
<add key="ContentType" value="application/hal+json; charset=UTF-8" />
I have a REST based API developed in JAVA. Now I am trying to call that API from a console based C# application i.e. from it's main function. I want to know is it possible to do that.
I have tried something but its not working
//I have written the below code in my class file. But the I can't find the RestClient class. What do I need to include this
static void Main(string[] args)
{
{
string endPoint = #"http:\\myRestService.com\api\";
var client = new RestClient(endPoint);
var json = client.MakeRequest();
}
}
From the documentation on asp.net site. this shows how it is done in C# , RestClient you tried to use is a lib, that encapsulate something like this sample. RestClient can be added as a nugget package.
using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
namespace ProductStoreClient
{
class Product
{
public string Name { get; set; }
public double Price { get; set; }
public string Category { get; set; }
}
class Program
{
static void Main()
{
RunAsync().Wait();
}
static async Task RunAsync()
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri("http://localhost:9000/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
// HTTP GET
HttpResponseMessage response = await client.GetAsync("api/products/1");
if (response.IsSuccessStatusCode)
{
Product product = await response.Content.ReadAsAsync<Product>();
Console.WriteLine("{0}\t${1}\t{2}", product.Name, product.Price, product.Category);
}
// HTTP POST
var gizmo = new Product() { Name = "Gizmo", Price = 100, Category = "Widget" };
response = await client.PostAsJsonAsync("api/products", gizmo);
if (response.IsSuccessStatusCode)
{
Uri gizmoUrl = response.Headers.Location;
// HTTP PUT
gizmo.Price = 80; // Update price
response = await client.PutAsJsonAsync(gizmoUrl, gizmo);
// HTTP DELETE
response = await client.DeleteAsync(gizmoUrl);
}
}
}
}
}
Pretty new with ASP.Net WEB API. Having some issues with the proper API configuration (and return type) for my API call which calls another ASHX service.
I have the following codes (tested in HomeController just to verify that the service call would work):
public async Task<ActionResult> Index()
{
WebRequest request = WebRequest.CreateHttp("http://callme/address.ashx");
var response = await request.GetResponseAsync();
string content;
using (var stream = response.GetResponseStream())
using(var reader = new StreamReader(stream))
{
content = await reader.ReadToEndAsync();
}
var result = JsonConvert.DeserializeObject<MyResult[]>(content);
return this.View();
}
public class MyResult
{
public string ClientAddress { get; set; }
}
Now, trying to port it over to an ASP.Net WEB API call:
ClientAddressController.cs
public class ClientAddressController: ApiController
{
public async IQueryable<MyResult> GetClientAddress()
{
WebRequest request = WebRequest.CreateHttp("http://callme/address.ashx");
var response = await request.GetResponseAsync();
string content;
using (var stream = response.GetResponseStream())
using(var reader = new StreamReader(stream))
{
content = await reader.ReadToEndAsync();
}
var result = JsonConvert.DeserializeObject<MyResult[]>(content);
// How to return the result object??
}
}
public class MyResult
{
public string ClientAddress { get; set; }
}
I need some help to properly define the correct parameters for the WEB Api call so that I could return the result object.
The result object would just be an array of strings:
[{"Address": "Address 100"}, {"Address": "Address 200"}, {"Address": "300"}]
Hoping to get some insights on resolving this. I have some idea with regards to returning database queries in Web API, but the service calls (and the async method) kind of threw me off the groove.
Thanks.
**UPDATE*****
Was able to find some resolution on this and I am posting the solution I have.
public class ClientAddressController: ApiController
{
public async Task<IHttpActionResult> GetClientAddress()
{
WebRequest request = WebRequest.CreateHttp("http://callme/address.ashx");
var response = await request.GetResponseAsync();
string content;
using (var stream = response.GetResponseStream())
using(var reader = new StreamReader(stream))
{
content = await reader.ReadToEndAsync();
}
var result = JsonConvert.DeserializeObject<MyResult[]>(content);
return Ok(result);
// How to return the result object??
}
}
public class MyResult
{
public string ClientAddress { get; set; }
}
P.S.: I am going to accept #Stripling's answer as his provided me some direction.
You'll need to create a class with an Address property, and map the results to objects of that class:
public async IQueryable<ClientAddressResult> GetClientAddress()
{
WebRequest request = WebRequest.CreateHttp("http://callme/address.ashx");
var response = await request.GetResponseAsync();
string content;
using (var stream = response.GetResponseStream())
using(var reader = new StreamReader(stream))
{
content = await reader.ReadToEndAsync();
}
IEnumerable<MyResult> result = JsonConvert.DeserializeObject<MyResult[]>(content);
return result.Select(r => new ClientAddressResult{Address = r.ClientAddress})
.AsQueryable();
}
DTO Classes:
public class MyResult
{
public string ClientAddress { get; set; }
}
public class ClientAddressResult
{
public string Address { get; set; }
}
You can return array values as dynamic List to be able to do that set method return with dynamic List.
var resultList = new List<dynamic>();
resultList.Add(new {Address="Address 100"});
resultList.Add(new {Address="Address 200"});
resultList.Add(new {Address="Address 300"});
return resultList;
Hope this is what you are loooking for.