原文:http://blog.csdn.net/haitaofeiyang/article/details/18362225
申公前几日和一个客户做系统对接，以前和客户对接一般采用webservice或者json 解析的方式，直接调用标准解析就可以。没想到客户用“请求响应模式”，直接访问人家的接口地址取数据，无奈打造一个通用的访问类吧
参考MSDN的解释：
HttpWebRequest类：提供WebRequest类的Http特定的实现。
HttpWebRequest 类对 WebRequest 中定义的属性和方法提供支持，也对使用户能够直接与使用 HTTP 的服务器交互的附加属性和方法提供支持。
不要使用构造函数创建HttpWebRequest实例，请使用System.Net.WebRequest.Create(URI uriString)来创建实例，如果URI是Http://或Https://，
返回的是HttpWebRequest对象。(建立请求特定URI的对象)
当向资源发送数据时，GetRequestStream方法返回用于发送数据的Stream对象。(获取请求数据的流对象)
GetResponse方法向RequestUri属性指定的资源发出同步请求并返回包含该响应的HttpWebResponse。(获取来自internet的响应)
好了，直接上代码：
using System.Net;
using System.IO;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;
using System.Windows.Forms;
/*
* 作者：申公
* 日期：
* 说明：此类提供http，POST和GET访问远程接口
* */
namespace ZJS.EDI.Business.HttpUtility
{
/// <summary>
/// 有关HTTP请求的辅助类
/// </summary>
public class HttpWebResponseUtility
{
private static readonly string DefaultUserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";//浏览器
private static Encoding requestEncoding = System.Text.Encoding.UTF8;//字符集
/// <summary>
/// 创建GET方式的HTTP请求
/// </summary>
/// <param name="url">请求的URL</param>
/// <param name="timeout">请求的超时时间</param>
/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
/// <returns></returns>
public static HttpWebResponse CreateGetHttpResponse(string url, int? timeout, string userAgent, CookieCollection cookies)
{
if (string.IsNullOrEmpty(url))
{
throw new ArgumentNullException("url");
}
HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
request.Method = "GET";
request.UserAgent = DefaultUserAgent;
if (!string.IsNullOrEmpty(userAgent))
{
request.UserAgent = userAgent;
}
if (timeout.HasValue)
{
request.Timeout = timeout.Value;
}
if (cookies != null)
{
request.CookieContainer = new CookieContainer();
request.CookieContainer.Add(cookies);
}
return request.GetResponse() as HttpWebResponse;
}
/// <summary>
/// 创建POST方式的HTTP请求
/// </summary>
/// <param name="url">请求的URL</param>
/// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
/// <returns></returns>
public static HttpWebResponse CreatePostHttpResponse(string url, string parameters, CookieCollection cookies)
{
if (string.IsNullOrEmpty(url))
{
throw new ArgumentNullException("url");
}
HttpWebRequest request = null;
Stream stream = null;//用于传参数的流
try
{
//如果是发送HTTPS请求
if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
{
ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
request = WebRequest.Create(url) as HttpWebRequest;
//创建证书文件
System.Security.Cryptography.X509Certificates.X509Certificate objx509 = new System.Security.Cryptography.X509Certificates.X509Certificate(Application.StartupPath + @"\licensefilezjs.cer");
//添加到请求里
request.ClientCertificates.Add(objx509);
request.ProtocolVersion = HttpVersion.Version10;
}
else
{
request = WebRequest.Create(url) as HttpWebRequest;
}
request.Method = "POST";//传输方式
request.ContentType = "application/x-www-form-urlencoded";//协议
request.UserAgent = DefaultUserAgent;//请求的客户端浏览器信息,默认IE
request.Timeout = 6000;//超时时间，写死6秒
//随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空
if (cookies != null)
{
request.CookieContainer = new CookieContainer();
request.CookieContainer.Add(cookies);
}
//如果需求POST传数据，转换成utf-8编码
byte[] data = requestEncoding.GetBytes(parameters);
request.ContentLength = data.Length;
stream = request.GetRequestStream();
stream.Write(data, 0, data.Length);
stream.Close();
}
catch (Exception ee)
{
//写日志
//LogHelper.
}
finally
{
if (stream != null)
{
stream.Close();
}
}
return request.GetResponse() as HttpWebResponse;
}
//验证服务器证书回调自动验证
private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
return true; //总是接受
}
/// <summary>
/// 获取数据
/// </summary>
/// <param name="HttpWebResponse">响应对象</param>
/// <returns></returns>
public static string OpenReadWithHttps(HttpWebResponse HttpWebResponse)
{
Stream responseStream = null;
StreamReader sReader = null;
String value = null;
try
{
// 获取响应流
responseStream = HttpWebResponse.GetResponseStream();
// 对接响应流(以"utf-8"字符集)
sReader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
// 开始读取数据
value = sReader.ReadToEnd();
}
catch (Exception)
{
//日志异常
}
finally
{
//强制关闭
if (sReader != null)
{
sReader.Close();
}
if (responseStream != null)
{
responseStream.Close();
}
if (HttpWebResponse != null)
{
HttpWebResponse.Close();
}
}
return value;
}
/// <summary>
/// 入口方法：获取传回来的XML文件
/// </summary>
/// <param name="url">请求的URL</param>
/// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
/// <returns></returns>
public static string GetResultXML(string url, string parameters, CookieCollection cookies)
{
return OpenReadWithHttps(CreatePostHttpResponse(url, parameters, cookies));
}
}
}
调用实例：
/// 调用主程序
/// </summary>
public class Program
{
static string strUrlPre = ; // 测试环境Url
static string strKey = ;// 签名密钥
static string strMethod = ;// 方法编号
static void Main(string[] args)
{
//MessageBox.Show("请注意，马上将进行保存操作!");
StringBuilder sbRequestData =;//请求参数
// 发送请求
StringBuilder sbUrl = new StringBuilder(); // 请求URL内容
sbUrl.Append(strUrlPre);
sbUrl.Append("?");
sbUrl.Append("sign=" + strKeyMD5);
sbUrl.Append("&" + sbSystemArgs.ToString());
String strUrl = sbUrl.ToString();
//解析xml文件
string resultXML = HttpWebResponseUtility.GetResultXML(sbUrl.ToString(), sbRequestData.ToString(), null);
}
}