关于c#:C-执行基本的-Web-POST-请求

这个办法用的是浏览器最传统的表单提交形式 application/x-www-form-urlencoded，这个办法可用到两种组合数据的办法，一是间接传递数据到 data 对象，二是组合键 / 值对类型的数据到 parameters 对象，办法内会优先选择 data 对象所带的参数，如果想要以键 / 值对的形式传递，将 data 对象的值填为空字符串即可，这两个二选一；获取返回值的办法中退出了异样解决，这使得即便在遇到申请服务器产生服务器谬误（如 404 等 HTTP 状态）时也可失常取得返回的异样信息，应用时须要留神超时值与字符编码集：

using System;
using System.Net;
using System.Text;
using System.IO;
using System.Collections.Generic;

public string HttpPost(string url, string data = "", IDictionary<string, string> parameters = null, int timeout = 5000, CookieCollection cookies = null)
{
    HttpWebRequest request = null;
    request = WebRequest.Create(url) as HttpWebRequest;
    request.Method = "POST";
    request.ContentType = "application/x-www-form-urlencoded";
    request.Timeout = timeout;
    if (cookies != null)
    {request.CookieContainer = new CookieContainer();
        request.CookieContainer.Add(cookies);
    }
    if (!string.IsNullOrWhiteSpace(data))
    {byte[] databytes = Encoding.UTF8.GetBytes(data);
        using (Stream stream = request.GetRequestStream())
        {stream.Write(databytes, 0, databytes.Length);
        }
    }
    else 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[] kvdata = Encoding.UTF8.GetBytes(buffer.ToString());
        using (Stream stream = request.GetRequestStream())
        {stream.Write(kvdata, 0, kvdata.Length);
        }
    }
    try
    {using (Stream stream = request.GetResponse().GetResponseStream())
        {using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {return reader.ReadToEnd();
            }
        }
    }
    catch (WebException ex)
    {using (Stream stream = ex.Response.GetResponseStream())
        {using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {return reader.ReadToEnd();
            }
        }
    }
}

相干环境：
.NET Framework 4.0