这是我到目前为止的代码:
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);
}
}
}
问题是我认为异常块正在被触发(因为当我删除try-catch时，我得到一个服务器错误(500)消息。但是我没有看到控制台。我在catch block里放了几行。
我的控制台:
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).
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
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;
}
职位:
// 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;
}
}
注意:为了序列化和反序列化JSON，我使用了Newtonsoft。Json NuGet包。
此处标记的答案建议直接使用HttpClient并销毁它。这可能会起作用，但是如果你没有正确地使用HttpClient，它很容易遇到问题。
如果您打算使用HttpClient，最好将HttpClient的创建/处理交给使用工厂模式的第三方库。RestClient。Net就是这样一个库。
它带有一个非常基本的HttpClient工厂，这样你就不会碰到套接字耗尽的问题，
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
}
但是微软的IHttpClientFactory实现也可以用于最新和最好的:
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考虑了依赖注入、模拟、IoC容器、单元可测试性，最重要的是速度快。我四处寻找，唯一的另一个客户端，似乎工作在类似的能力是flul . http。
第一步是为HTTP客户机创建helper类。
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;
}
}
}
然后可以在代码中使用这个类。
这是如何使用上面的类调用不带承载的REST API的示例。
// 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();
}
这是一个如何调用需要承载的REST API的示例。
// 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();
}
如果您想查看它如何工作的工作示例，还可以参考下面的存储库。
https://github.com/mokh223/callApi
