不错博客：
[C#HttpHelper]官方产品发布与源码下载---苏飞版
http://www.sufeinet.com/thread-3-1-1.html
http://blog.****.net/xxj_jing/article/details/8107882
http://zhoufoxcn.blog.51cto.com/792419/561934/
http://www.dedecms.com/knowledge/program/asp-donet/2012/0803/4214.html
http://blog.****.net/zhoufoxcn/article/details/6404236
C# winform post 请求指定 url
/// <summary>
/// 请求信息帮助
/// </summary>
public class HttpHelper
{
/// <summary>
/// post 请求指定地址返回响应数据
/// </summary>
/// <param name="url">请求地址</param>
/// <param name="postData">请求数据</param>
/// <param name="timeout">请求超时时间（毫秒）</param>
/// <param name="requestCoding">请求编码</param>
/// <param name="responseCoding">响应编码</param>
/// <returns></returns>
public string PostRequest(string url, Dictionary<string, string> postData, int timeout, Encoding requestCoding, Encoding responseCoding)
{
string postStr = string.Empty;
if (postData != null)
{
postData.All(o =>
{
if (string.IsNullOrEmpty(postStr))
postStr = string.Format("{0}={1}", o.Key, o.Value);
else
postStr += string.Format("&{0}={1}", o.Key, o.Value); return true;
});
}
return PostRequest(url, postStr, timeout, requestCoding, responseCoding);
}
/// <summary>
/// post 请求指定地址返回响应数据
/// </summary>
/// <param name="url">请求地址</param>
/// <param name="postData">请求数据</param>
/// <param name="timeout">请求超时时间（毫秒）</param>
/// <param name="requestCoding">请求编码</param>
/// <param name="responseCoding">响应编码</param>
/// <returns></returns>
public string PostRequest(string url, string postData, int timeout, Encoding requestCoding, Encoding responseCoding)
{
string postUrl = VerifyUrl(url);
try
{
//写入POSTDATE里
byte[] byteArray = requestCoding.GetBytes(postData);
HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(new Uri(postUrl));
webRequest.Method = "POST";
webRequest.Timeout = timeout;
webRequest.ContentType = "application/x-www-form-urlencoded";
webRequest.ContentLength = byteArray.Length;
Stream newStream = webRequest.GetRequestStream();
newStream.Write(byteArray, 0, byteArray.Length);
newStream.Close();
//接收返回信息：
HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
StreamReader php = new StreamReader(response.GetResponseStream(), responseCoding);
string result = php.ReadToEnd();
return result;
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// 验证URL
/// </summary>
/// <param name="url">待验证 URL</param>
/// <returns></returns>
private string VerifyUrl(string url)
{
if (string.IsNullOrEmpty(url))
throw new Exception("URL 地址不可以为空！"); if (url.StartsWith("http://", StringComparison.CurrentCultureIgnoreCase))
return url; return string.Format("http://{1}", url);
}
}
/// <summary>
/// Http请求
/// </summary>
public class HttpUtility
{
/// <summary>
///通用HttpWebRequest
/// </summary>
/// <param name="method">请求方式（POST/GET）</param>
/// <param name="url">请求地址</param>
/// <param name="param">请求参数</param>
/// <param name="onComplete">完成后执行的操作(可选参数，通过此方法可以获取到HTTP状态码)</param>
/// <returns>请求返回的结果</returns>
public static string Request(string method, string url, string param, Action<HttpStatusCode, string> onComplete = null)
{
if (string.IsNullOrEmpty(url))
throw new ArgumentNullException("URL"); switch (method.ToUpper())
{
case "POST":
return Post(url, param, onComplete);
case "GET":
return Get(url, param, onComplete);
default:
throw new EntryPointNotFoundException("method:" + method);
}
} /// <summary>
/// Post请求
/// </summary>
/// <param name="url">请求地址</param>
/// <param name="param">参数</param>
/// <param name="onComplete">完成后执行的操作(可选参数，通过此方法可以获取到HTTP状态码)</param>
/// <returns>请求返回的结果</returns>
public static string Post(string url, string param, Action<HttpStatusCode, string> onComplete = null)
{
UrlCheck(ref url); byte[] bufferBytes = Encoding.UTF8.GetBytes(param); var request = WebRequest.Create(url) as HttpWebRequest;//HttpWebRequest方法继承自WebRequest, Create方法在WebRequest中定义，因此此处要显示的转换
request.Method = "POST";
request.ContentLength = bufferBytes.Length;
request.ContentType = "application/x-www-form-urlencoded"; try
{
using (var requestStream = request.GetRequestStream())
{
requestStream.Write(bufferBytes, , bufferBytes.Length);
}
}
catch (WebException ex)
{ return ex.Message;
} return HttpRequest(request, onComplete);
} /// <summary>
/// GET请求
/// </summary>
/// <param name="url">请求地址</param>
/// <param name="param">参数</param>
/// <param name="onComplete">完成后执行的操作(可选参数，通过此方法可以获取到HTTP状态码)</param>
/// <returns>请求返回结果</returns>
public static string Get(string url, string param, Action<HttpStatusCode, string> onComplete = null)
{
UrlCheck(ref url); if (!string.IsNullOrEmpty(param))
if (!param.StartsWith("?"))
param += "?" + param;
else
param += param; var request = WebRequest.Create(url) as HttpWebRequest;
request.Method = "GET";
request.ContentType = "application/x-www-form-urlencoded"; return HttpRequest(request, onComplete);
} /// <summary>
/// 请求的主体部分（由此完成请求并返回请求结果）
/// </summary>
/// <param name="request">请求的对象</param>
/// <param name="onComplete">完成后执行的操作(可选参数，通过此方法可以获取到HTTP状态码)</param>
/// <returns>请求返回结果</returns>
private static string HttpRequest(HttpWebRequest request, Action<HttpStatusCode, string> onComplete = null)
{
HttpWebResponse response = null; try
{
response = request.GetResponse() as HttpWebResponse;
}
catch (WebException ex)
{
response = ex.Response as HttpWebResponse;
} if (response == null)
{
if (onComplete != null)
onComplete(HttpStatusCode.NotFound, "请求远程返回为空");
return null;
} string result = string.Empty;
using (StreamReader reader = new StreamReader(response.GetResponseStream()))
{
result = reader.ReadToEnd();
} if (onComplete != null)
onComplete(response.StatusCode, result); return result; } /// <summary>
/// URL拼写完整性检查
/// </summary>
/// <param name="url">待检查的URL</param>
private static void UrlCheck(ref string url)
{
if (!url.StartsWith("http://") && !url.StartsWith("https://"))
url = "http://" + url;
}
}