如何使用 C# 调用 REST API? [英] How do I make calls to a REST API using C#?
问题描述
这是我目前的代码:
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，我收到服务器错误 (500) 消息.但我没有看到我放入的 Console.Out 行捕获块.
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.
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:usersl. preston sego iiidocumentsvisual studio 11ProjectsConsoleApplication1ConsoleApplication1inDebugConsoleApplication1.exe', Symbols loaded.
'ConsoleApplication1.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:WindowsMicrosoft.NetassemblyGAC_MSILSystem.Configurationv4.0_4.0.0.0__b03f5f7f11d50a3aSystem.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).
推荐答案
ASP.NET Web API 已经取代了 WCF 前面提到的 Web API.
The ASP.NET Web API has replaced the WCF Web API previously mentioned.
我想我会发布一个更新的答案，因为这些回复大多来自 2012 年初，并且该主题是在 Google 上搜索call restful service C#"时的最佳结果之一.
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#".
Microsoft 当前的指导方针是使用 Microsoft ASP.NET Web API 客户端库来使用 RESTful 服务.这可用作 NuGet 包 Microsoft.AspNet.WebApi.Client.您需要将此 NuGet 包添加到您的解决方案中.
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.
以下是您的示例在使用 ASP.NET Web API 客户端库实现时的外观:
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();
}
}
}
如果您计划发出多个请求，您应该重新使用您的 HttpClient 实例.有关在这种情况下为何不在 HttpClient 实例上使用 using 语句的更多详细信息，请参阅此问题及其答案:HttpClient 和 HttpClientHandler 是否必须在请求之间进行处理?
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?
有关更多详细信息，包括其他示例，请参阅从 .NET 客户端 (C#) 调用 Web API
For more details, including other examples, see Call a Web API From a .NET Client (C#)
这篇博文也可能有用:使用 HttpClient 使用 ASP.NET Web API REST 服务
This blog post may also be useful: Using HttpClient to Consume ASP.NET Web API REST Services
这篇关于如何使用 C# 调用 REST API?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
