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).
一种ASP解决方案。NET核心:
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();
}
}
}
}
要发布，可以使用这样的代码:
await HttpHelper.Post<Setting>($"/api/values/{id}", setting);
删除示例:
await HttpHelper.Delete($"/api/values/{id}");
获取列表的示例:
List<ClaimTerm> claimTerms = await HttpHelper.Get<List<ClaimTerm>>("/api/values/");
示例只获取一个:
ClaimTerm processedClaimImage = await HttpHelper.Get<ClaimTerm>($"/api/values/{id}");
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
以下是在c#中调用外部API的几种不同方式(2019年更新)。
.NET的内置方式:
webrequest和WebClient——冗长的api和微软的文档不是很容易理解
HttpClient - . net的最新产品&使用起来比上面提到的简单多了。
免费、开源的NuGet包，坦率地说，它比。net内置客户端有更好的开发体验:
ServiceStack。文本(1000个GitHub星，700万NuGet下载)(*)-快速，轻便和弹性。
RestSharp(6000个GitHub星，2300万NuGet下载)(*)-简单的REST和HTTP API客户端
Flurl (1700 GitHub星，300万NuGet下载)(*)-一个流畅，可移植，可测试的HTTP客户端库
上面所有的包都提供了很棒的开发体验(即简洁、简单的API)，并且维护得很好。
(*)截至2019年8月
示例:使用servicstack . text从伪Rest API获取Todo项。
其他库具有非常相似的语法。
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; }
}
}
在. net核心控制台应用程序中运行上述示例，产生以下输出。
使用NuGet安装这些包
Install-Package ServiceStack.Text, or
Install-Package RestSharp, or
Install-Package Flurl.Http
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。
