c# post和get请求

// <summary>
/// 发送http post请求
/// </summary>
/// <param name="url">地址</param>
/// <param name="parameters">查询参数集合</param>
/// <returns></returns>
public string CreatePostHttpResponse(string url,IDictionary<string,string> parameters)
{
    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;//创建请求对象
    request.Method = "POST";//请求方式
    request.ContentType = "application/x-www-form-urlencoded";//链接类型
    //构造查询字符串
    if (!(parameters == null || parameters.Count == 0))
    {
        StringBuilder buffer = new StringBuilder();
        bool first = true;
        foreach (string key in parameters.Keys)
        {
 
            if (!first)
            {
                buffer.AppendFormat("&{0}={1}",key,parameters[key]);
            }
            else
            {
                buffer.AppendFormat("{0}={1}",parameters[key]);
                first = false;
            }
        }
        byte[] data = Encoding.UTF8.GetBytes(buffer.ToString());
        //写入请求流
        using (Stream stream = request.GetRequestStream())
        {
            stream.Write(data,0,data.Length);
        }
    }
    return GetResponseString((HttpWebResponse)request.GetResponse());

 }

/// <summary> /// 发送http Get请求 /// </summary> 
/// <param name="url"></param> 
/// <returns></returns> 
public string CreateGetHttpResponse(string url) 
{ 
　　HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest; 
　　request.Method = "GET"; 
　　request.ContentType = "application/x-www-form-urlencoded";//链接类型 
　　return GetResponseString((HttpWebResponse)request.GetResponse()); 
} 

/// <summary> /// 从HttpWebResponse对象中提取响应的数据转换为字符串 /// </summary> 
/// <param name="webresponse"></param> 
/// <returns></returns> 
public string GetResponseString(HttpWebResponse webresponse) 
{ 
　　using (Stream s = webresponse.GetResponseStream()) 
   { 
　　　　StreamReader reader = new StreamReader(s,Encoding.UTF8); return reader.ReadToEnd();    } }