与此无关，我确定，但请使用块包装您的IDisposable对象，以确保适当的处置:

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);
            }
        }
    }
}

与此无关，我确定，但请使用块包装您的IDisposable对象，以确保适当的处置:

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);
            }
        }
    }
}

由于您使用的是Visual Studio 11 Beta，您将希望使用最新的和最好的。新的Web API包含了这方面的类。

参见HttpClient: http://wcf.codeplex.com/wikipage?title=WCF%20HTTP

我们已经开始使用地下酒吧了。这很棒:

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)

ASP。NET Web API已经取代了前面提到的WCF Web API。

我想我应该发布一个更新的答案，因为这些回答大部分来自2012年初，当在谷歌上搜索“调用基于rest的服务c#”时，这个帖子是排名靠前的结果之一。

目前微软的指导方针是使用微软ASP。NET Web API客户端库来使用RESTful服务。这是一个NuGet包，Microsoft.AspNet.WebApi.Client。您需要将这个NuGet包添加到您的解决方案中。

下面是使用ASP实现示例时的外观。NET Web API客户端库:

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();
        }
    }
}

如果您计划发出多个请求，您应该重用HttpClient实例。请参阅这个问题及其答案，以了解为什么在这种情况下没有在HttpClient实例上使用using语句的更多细节:HttpClient和HttpClientHandler必须在请求之间被处理吗?

有关更多细节，包括其他示例，请参见从。net客户端调用Web API (c#)

这篇博客文章也可能有用:使用HttpClient消费ASP。NET Web API REST服务

查看Refit从. net调用REST服务。我发现它很容易使用:

改装:自动类型安全的REST库。net Core, Xamarin和 net Refit是一个很大程度上受到Square的Retrofit库启发的库 它把你的REST API变成一个活动接口:

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");