c# . net

    using System.Net.Http;
    
    private static readonly HttpClient httpClient = new HttpClient();

//POST    
    var values = new Object();
    values[0] = "Value1";
    values[2] = "Value2";
    values[n] = "ValueN";

    var content = new FormUrlEncodedContent(values);
    var response = await httpClient.PostAsync("URL", content);
    var responseString = await response.Content.ReadAsStringAsync();

    

//GET
 var response = await httpClient.GetStringAsync("URL");

当使用Windows.Web.Http命名空间时，对于POST而不是FormUrlEncodedContent，我们编写HttpFormUrlEncodedContent。同样，响应类型为HttpResponseMessage。其余的就像Evan Mulawski写的那样。

这是一个完整的JSON格式发送/接收数据的工作示例，我使用Visual Studio 2013 Express Edition:

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using System.Web.Script.Serialization;

namespace ConsoleApplication1
{
    class Customer
    {
        public string Name { get; set; }
        public string Address { get; set; }
        public string Phone { get; set; }
    }

    public class Program
    {
        private static readonly HttpClient _Client = new HttpClient();
        private static JavaScriptSerializer _Serializer = new JavaScriptSerializer();

        static void Main(string[] args)
        {
            Run().Wait();
        }

        static async Task Run()
        {
            string url = "http://www.example.com/api/Customer";
            Customer cust = new Customer() { Name = "Example Customer", Address = "Some example address", Phone = "Some phone number" };
            var json = _Serializer.Serialize(cust);
            var response = await Request(HttpMethod.Post, url, json, new Dictionary<string, string>());
            string responseText = await response.Content.ReadAsStringAsync();

            List<YourCustomClassModel> serializedResult = _Serializer.Deserialize<List<YourCustomClassModel>>(responseText);

            Console.WriteLine(responseText);
            Console.ReadLine();
        }

        /// <summary>
        /// Makes an async HTTP Request
        /// </summary>
        /// <param name="pMethod">Those methods you know: GET, POST, HEAD, etc...</param>
        /// <param name="pUrl">Very predictable...</param>
        /// <param name="pJsonContent">String data to POST on the server</param>
        /// <param name="pHeaders">If you use some kind of Authorization you should use this</param>
        /// <returns></returns>
        static async Task<HttpResponseMessage> Request(HttpMethod pMethod, string pUrl, string pJsonContent, Dictionary<string, string> pHeaders)
        {
            var httpRequestMessage = new HttpRequestMessage();
            httpRequestMessage.Method = pMethod;
            httpRequestMessage.RequestUri = new Uri(pUrl);
            foreach (var head in pHeaders)
            {
                httpRequestMessage.Headers.Add(head.Key, head.Value);
            }
            switch (pMethod.Method)
            {
                case "POST":
                    HttpContent httpContent = new StringContent(pJsonContent, Encoding.UTF8, "application/json");
                    httpRequestMessage.Content = httpContent;
                    break;

            }

            return await _Client.SendAsync(httpRequestMessage);
        }
    }
}

MSDN有一个样本。

using System;
using System.IO;
using System.Net;
using System.Text;

namespace Examples.System.Net
{
    public class WebRequestPostExample
    {
        public static void Main()
        {
            // Create a request using a URL that can receive a post. 
            WebRequest request = WebRequest.Create("http://www.contoso.com/PostAccepter.aspx");
            // Set the Method property of the request to POST.
            request.Method = "POST";
            // Create POST data and convert it to a byte array.
            string postData = "This is a test that posts this string to a Web server.";
            byte[] byteArray = Encoding.UTF8.GetBytes(postData);
            // Set the ContentType property of the WebRequest.
            request.ContentType = "application/x-www-form-urlencoded";
            // Set the ContentLength property of the WebRequest.
            request.ContentLength = byteArray.Length;
            // Get the request stream.
            Stream dataStream = request.GetRequestStream();
            // Write the data to the request stream.
            dataStream.Write(byteArray, 0, byteArray.Length);
            // Close the Stream object.
            dataStream.Close();
            // Get the response.
            WebResponse response = request.GetResponse();
            // Display the status.
            Console.WriteLine(((HttpWebResponse)response).StatusDescription);
            // Get the stream containing content returned by the server.
            dataStream = response.GetResponseStream();
            // Open the stream using a StreamReader for easy access.
            StreamReader reader = new StreamReader(dataStream);
            // Read the content.
            string responseFromServer = reader.ReadToEnd();
            // Display the content.
            Console.WriteLine(responseFromServer);
            // Clean up the streams.
            reader.Close();
            dataStream.Close();
            response.Close();
        }
    }
}

这个解决方案只使用标准的. net调用。

测试:

在企业WPF应用程序中使用。使用async/await来避免阻塞UI。 兼容。net 4.5+。 在没有参数的情况下进行测试(在幕后需要一个“GET”)。 使用参数进行测试(需要幕后的“POST”)。 使用标准的网页(如谷歌)进行测试。 使用内部基于java的web服务进行测试。

参考:

// Add a Reference to the assembly System.Web

代码:

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web;

private async Task<WebResponse> CallUri(string url, TimeSpan timeout)
{
    var uri = new Uri(url);
    NameValueCollection rawParameters = HttpUtility.ParseQueryString(uri.Query);
    var parameters = new Dictionary<string, string>();
    foreach (string p in rawParameters.Keys)
    {
        parameters[p] = rawParameters[p];
    }

    var client = new HttpClient { Timeout = timeout };
    HttpResponseMessage response;
    if (parameters.Count == 0)
    {
        response = await client.GetAsync(url);
    }
    else
    {
        var content = new FormUrlEncodedContent(parameters);
        string urlMinusParameters = uri.OriginalString.Split('?')[0]; // Parameters always follow the '?' symbol.
        response = await client.PostAsync(urlMinusParameters, content);
    }
    var responseString = await response.Content.ReadAsStringAsync();

    return new WebResponse(response.StatusCode, responseString);
}

private class WebResponse
{
    public WebResponse(HttpStatusCode httpStatusCode, string response)
    {
        this.HttpStatusCode = httpStatusCode;
        this.Response = response;
    }
    public HttpStatusCode HttpStatusCode { get; }
    public string Response { get; }
}

不带参数调用(在幕后使用“GET”):

 var timeout = TimeSpan.FromSeconds(300);
 WebResponse response = await this.CallUri("http://www.google.com/", timeout);
 if (response.HttpStatusCode == HttpStatusCode.OK)
 {
     Console.Write(response.Response); // Print HTML.
 }

使用参数调用(在幕后使用“POST”):

 var timeout = TimeSpan.FromSeconds(300);
 WebResponse response = await this.CallUri("http://example.com/path/to/page?name=ferret&color=purple", timeout);
 if (response.HttpStatusCode == HttpStatusCode.OK)
 {
     Console.Write(response.Response); // Print HTML.
 }

为什么这不是完全无关紧要的?执行请求并不是处理结果。而且似乎还涉及到一些。net Bug——参见HttpClient中的Bug。GetAsync应该抛出WebException，而不是TaskCanceledException

我最终得到了这样的代码:

static async Task<(bool Success, WebExceptionStatus WebExceptionStatus, HttpStatusCode? HttpStatusCode, string ResponseAsString)> HttpRequestAsync(HttpClient httpClient, string url, string postBuffer = null, CancellationTokenSource cts = null) {
    try {
        HttpResponseMessage resp = null;

        if (postBuffer is null) {
            resp = cts is null ? await httpClient.GetAsync(url) : await httpClient.GetAsync(url, cts.Token);

        } else {
            using (var httpContent = new StringContent(postBuffer)) {
                resp = cts is null ? await httpClient.PostAsync(url, httpContent) : await httpClient.PostAsync(url, httpContent, cts.Token);
            }
        }

        var respString = await resp.Content.ReadAsStringAsync();
        return (resp.IsSuccessStatusCode, WebExceptionStatus.Success, resp.StatusCode, respString);

    } catch (WebException ex) {
        WebExceptionStatus status = ex.Status;
        if (status == WebExceptionStatus.ProtocolError) {
            // Get HttpWebResponse so that you can check the HTTP status code.
            using (HttpWebResponse httpResponse = (HttpWebResponse)ex.Response) {
                return (false, status, httpResponse.StatusCode, httpResponse.StatusDescription);
            }
        } else {
            return (false, status, null, ex.ToString());
        }

    // https://devblogs.microsoft.com/dotnet/net-5-new-networking-improvements/
    } catch (TaskCanceledException ex) when (ex.InnerException is TimeoutException) {
        return (false, ex.ToString(), null, WebExceptionStatus.Timeout);

    } catch (TaskCanceledException ex) {
        return (false, ex.ToString(), null, WebExceptionStatus.RequestCanceled);

    } catch (Exception ex) {
        return (false, WebExceptionStatus.UnknownError, null, ex.ToString());
    }
}

这将根据postBuffer是否为空来执行GET或POST操作。

如果Success为true，响应将在ResponseAsString中。

如果Success为false，你可以检查WebExceptionStatus, HttpStatusCode和ResponseAsString，看看哪里出了问题。