C#中使用web API post

以下为本人到目前为止对Post使用的一些了解：

.net 4.5以上版本（可能服务端也要使用4.5以上的版本）

用到的名称空间：

using System.Net.Http;
using System.Data;

实现：public async void send(string strSend)

        {            
            //转码，byte[] change = Encoding.UTF8.GetBytes(str);也可以
            Encoding charset = Encoding.GetEncoding("utf-8");
            byte[] change = charset.GetBytes(strSend);
            string sendUtf = charset.GetString(change);
            var handler = new HttpClientHandler();
            try
            {
                using (var http = new HttpClient(handler))
                {
　　　　　　　　　　　　//将要发送的内容放入Dictionary中，通过函数转换为content
                    var content = new FormUrlEncodedContent(new Dictionary<string, string>()
                {
                    {"iNum","1"},
                    {"sName",sendUtf}
                });
　　　　　　　　　　　　//异步
                    var response = await http.PostAsync(url, content);
                 
                    response.EnsureSuccessStatusCode();
                    System.Windows.Forms.MessageBox.Show(await response.Content.ReadAsStringAsync());
                    
                }
            }
            catch(Exception e)
            {
                System.Windows.Forms.MessageBox.Show(e.Message);
            }
        }

此方法已验证，但是可能存在问题，会进一步完善。

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因为.net 4.5一下没有System.Net.Http程序集，所以vs2012以下并不能使用HttpClient，但是从网上查阅发现可以使用HttpWebRequest和HttpWebResponse来实现，如下：

使用的名称空间：

using System.Net;
using System.Text.RegularExpressions;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;

实现：

public HttpWebResponse send(string strSend)
        {
            HttpWebRequest request = null;
            ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
            request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.UserAgent = DefaultUserAgent;
            Encoding charset = Encoding.GetEncoding("utf-8");
            byte[] change = charset.GetBytes(strSend);
            string sendUtf = charset.GetString(change);
            IDictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("iNum", "1");
            parameters.Add("sName", sendUtf);
            if (!(parameters == null || parameters.Count == 0))
            {
                StringBuilder buffer = new StringBuilder();
                int i = 0;
                foreach (string key in parameters.Keys)
                {
                    if (i > 0)
                    {
                        buffer.AppendFormat("&{0}={1}", key, parameters[key]);
                    }
                    else
                    {
                        buffer.AppendFormat("{0}={1}", key, parameters[key]);
                    }
                    i++;
                }
                byte[] data = charset.GetBytes(buffer.ToString());
                using (Stream stream = request.GetRequestStream())
                {
                    stream.Write(data, 0, data.Length);
                }
                return request.GetResponse as HttpWebResponse;
            }
        }
        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
            return true; //总是接受   
        }

这种方法因为服务端的原因并未验证。

以于2016-04-28验证，通过两种方法的使用，因为对HttpClient的了解较少，所以感觉使用HttpWebResponse更通用，复用性更高一些。下面贴出我自己写的

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.IO;
using System.Web;
using System.Runtime.InteropServices;

namespace Check0421
{
    
    class HttpRequst
    {
        [DllImport("wininet.dll")]
        private extern static bool InternetGetConnectedState(int Description, int ReservedValue);
        public string GetHttpResponse(Dictionary<string,string> dicList,Encoding charset,string url)
        {
            if (!IsConnectInternet())
            {
                System.Windows.Forms.MessageBox.Show("网络连接不可用...");
                return "";
            }
            HttpWebRequest request = null;
            request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.Timeout = 20000;
            
            using(Stream sm=request.GetRequestStream())
            {
                byte[] bySend = SendString(dicList, charset);
                sm.Write(bySend, 0, bySend.Length);
            }
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            Stream st = response.GetResponseStream();
            StreamReader sr = new StreamReader(st);
            string str=sr.ReadToEnd();
            return str;
        }
        private byte[] SendString(Dictionary<string,string> dicList, Encoding charset)
        {
            
            string send = "";
            foreach(var item in dicList)
            {
                byte[] byk=charset.GetBytes(item.Key);
                string strCodek=charset.GetString(byk);
                byte[] byv = charset.GetBytes(item.Value);
                string strCodev = charset.GetString(byv);
                send += strCodek + "=" + strCodev + "&";
            }
            send = send.Substring(0, send.LastIndexOf('&'));
            return charset.GetBytes(send);
        }
        private bool IsConnectInternet()
        {
            int Description = 0;
            return InternetGetConnectedState(Description, 0);
        }

    }
}

自己的理解不够深，正在学习，如有问题，敬请指出。

 

本文引用了：http://www.cnblogs.com/lori/的内容，如有侵权纯属无意，请联系我删除。

感谢各位博主的文章让我学习到使用方法，如有侵权纯属无意，请联系我删除。