请求url数据

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

namespace TheDataTransfer.Dao
{
    class Transfer
    {
        /*
    *  url:POST请求地址
    *  postData:json格式的请求报文,例如：{"key1":"value1","key2":"value2"}
    */

     public static string PostJsonUrl(string url, string postData)
        {
            string result = "";

            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);

            req.Method = "POST";

            req.Timeout = 800;//设置请求超时时间，单位为毫秒

            req.ContentType = "application/json";

            byte[] data = Encoding.UTF8.GetBytes(postData);

            req.ContentLength = data.Length;

            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(data, 0, data.Length);

                reqStream.Close();
            }

            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();

            Stream stream = resp.GetResponseStream();

            //获取响应内容
            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {
                result = reader.ReadToEnd();
            }

            return result;
        }



     public static string PostXmlUrl(string url, string Data)
     {
         string result = "";

         StreamWriter myWriter = null;

         HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
         objRequest.Method = "POST";
         objRequest.ContentLength = Data.Length;
         objRequest.ContentType = "text/xml";//提交xml 
         //objRequest.ContentType = "application/x-www-form-urlencoded";//提交表单
         try
         {
             myWriter = new StreamWriter(objRequest.GetRequestStream());
             myWriter.Write(Data);
         }
         catch (Exception e)
         {
             return e.Message;
         }
         finally
         {
             myWriter.Close();
         }

         HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
         using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
         {
             result = sr.ReadToEnd();
             sr.Close();
         }
         return result;
     }



     protected string GetWebContent(string url)
     {
         Stream outstream = null;
         Stream instream = null;
         StreamReader sr = null;
         HttpWebResponse response = null;
         HttpWebRequest request = null;
         // 要注意的这是这个编码方式，还有内容的Xml内容的编码方式
         Encoding encoding = Encoding.GetEncoding("GBK");
         byte[] data = encoding.GetBytes(url);

         // 准备请求,设置参数
         request = WebRequest.Create(url) as HttpWebRequest;
         request.Method = "POST";
         //request.ContentType = "text/plain";
         request.ContentLength = data.Length;

         outstream = request.GetRequestStream();
         outstream.Write(data, 0, data.Length);
         outstream.Flush();
         outstream.Close();
         //发送请求并获取相应回应数据

         response = request.GetResponse() as HttpWebResponse;
         //直到request.GetResponse()程序才开始向目标网页发送Post请求
         instream = response.GetResponseStream();
         sr = new StreamReader(instream, encoding);
         //返回结果网页(html)代码

         string content = sr.ReadToEnd();
         return content;
     }
    }
}