HTTP GET POST 获取

public class WebHttp
{
	/// <summary>
	/// get请求带重试
	/// </summary>
	/// <param name="Url"></param>
	/// <param name="postDataStr"></param>
	/// <param name="sum"></param>
	/// <returns></returns>
	public static string HttpGet(string Url, string postDataStr, int sum)
	{
		string temp=null;
		for (int i = 0; i < sum; i++)
		{
			if (string.IsNullOrEmpty(temp) || string.IsNullOrEmpty(temp.Trim()))
			{
				temp = HttpGet(Url, postDataStr);
			}
			else {
				break;
			}
		}
		return temp;
	}
	/// <summary>
	/// post请求带重试
	/// </summary>
	/// <param name="Url"></param>
	/// <param name="postDataStr"></param>
	/// <param name="sum"></param>
	/// <returns></returns>
	public static string HttpPost(string Url, string postDataStr, int sum)
	{
		string temp = null;
		for (int i = 0; i < sum; i++)
		{
			if (string.IsNullOrEmpty(temp) || string.IsNullOrEmpty(temp.Trim()))
			{
				temp = HttpPost(Url, postDataStr);
			}
			else
			{
				break;
			}
		}
		return temp;
	}
	/// <summary>
	/// GET请求与获取结果
	/// </summary>
	public static string HttpGet(string Url, string postDataStr)
	{
		try
		{
			HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr);
			request.Method = "GET";
			request.ContentType = "text/html;charset=UTF-8";
			request.Timeout = 10000;
			HttpWebResponse response = (HttpWebResponse)request.GetResponse();
			Stream myResponseStream = response.GetResponseStream();
			StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.UTF8);
			string retString = myStreamReader.ReadToEnd();
			myStreamReader.Close();
			myResponseStream.Close();
			return retString;
		}
		catch (Exception ex)
		{
			return null;
		}
	}
	/// <summary>
	/// POST请求与获取结果
	/// </summary>
	public static string HttpPost(string Url, string postDataStr)
	{
		try
		{
			HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
			request.Method = "POST";
			request.Timeout = 6000000;
			request.ContentType = "application/x-www-form-urlencoded";
			request.ContentLength = postDataStr.Length;
			StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
			writer.Write(postDataStr);
			writer.Flush();
			HttpWebResponse response = (HttpWebResponse)request.GetResponse();
			string encoding = response.ContentEncoding;
			if (encoding == null || encoding.Length < 1)
			{
				encoding = "UTF-8"; //默认编码
			}
			StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
			string retString = reader.ReadToEnd();
			return retString;
		}
		catch (Exception ex)
		{
			return null;
		}
	}
}

 /// <summary>
        /// Http (GET/POST)
        /// </summary>
        /// <param name="url">请求URL</param>
        /// <param name="parameters">请求参数</param>
        /// <param name="method">请求方法</param>
        /// <returns>响应内容</returns>
        public string HttpSendPost(string url, IDictionary<string, string> parameters, string method)
        {
            if (method.ToLower() == "post")
            {
                HttpWebRequest req = null;
                HttpWebResponse rsp = null;
                System.IO.Stream reqStream = null;
                try
                {
                    req = (HttpWebRequest)WebRequest.Create(url);
                    req.Method = method;
                    req.KeepAlive = false;
                    req.ProtocolVersion = HttpVersion.Version10;
                    req.Timeout = 5000;
                    req.ContentType = "application/x-www-form-urlencoded;charset=utf-8";
                    byte[] postData = Encoding.UTF8.GetBytes(BuildQuery(parameters, "utf8"));
                    reqStream = req.GetRequestStream();
                    reqStream.Write(postData, 0, postData.Length);
                    rsp = (HttpWebResponse)req.GetResponse();
                    Encoding encoding = Encoding.GetEncoding(rsp.CharacterSet);
                    return GetResponseAsString(rsp, encoding);
                }
                catch (Exception ex)
                {
                    return ex.Message;
                }
                finally
                {
                    if (reqStream != null) reqStream.Close();
                    if (rsp != null) rsp.Close();
                }
            }
            else
            {
                //创建请求
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url + "?" + BuildQuery(parameters, "utf8"));

                //GET请求
                request.Method = "GET";
                request.ReadWriteTimeout = 5000;
                request.ContentType = "text/html;charset=UTF-8";
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                Stream myResponseStream = response.GetResponseStream();
                StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));

                //返回内容
                string retString = myStreamReader.ReadToEnd();
                return retString;
            }
        }
        /// <summary>
        /// 组装普通文本请求参数。
        /// </summary>
        /// <param name="parameters">Key-Value形式请求参数字典</param>
        /// <returns>URL编码后的请求数据</returns>
        public static string BuildQuery(IDictionary<string, string> parameters, string encode)
        {
            StringBuilder postData = new StringBuilder();
            bool hasParam = false;
            IEnumerator<KeyValuePair<string, string>> dem = parameters.GetEnumerator();
            while (dem.MoveNext())
            {
                string name = dem.Current.Key;
                string value = dem.Current.Value;
                // 忽略参数名或参数值为空的参数
                if (!string.IsNullOrEmpty(name))//&& !string.IsNullOrEmpty(value)
                {
                    if (hasParam)
                    {
                        postData.Append("&");
                    }
                    postData.Append(name);
                    postData.Append("=");
                    if (encode == "gb2312")
                    {
                        postData.Append(HttpUtility.UrlEncode(value, Encoding.GetEncoding("gb2312")));
                    }
                    else if (encode == "utf8")
                    {
                        postData.Append(HttpUtility.UrlEncode(value, Encoding.UTF8));
                    }
                    else
                    {
                        postData.Append(value);
                    }
                    hasParam = true;
                }
            }
            return postData.ToString();
        }

        /// <summary>
        /// 把响应流转换为文本。
        /// </summary>
        /// <param name="rsp">响应流对象</param>
        /// <param name="encoding">编码方式</param>
        /// <returns>响应文本</returns>
        public static string GetResponseAsString(HttpWebResponse rsp, Encoding encoding)
        {
            System.IO.Stream stream = null;
            StreamReader reader = null;
            try
            {
                // 以字符流的方式读取HTTP响应
                stream = rsp.GetResponseStream();
                reader = new StreamReader(stream, encoding);
                return reader.ReadToEnd();
            }
            finally
            {
                // 释放资源
                if (reader != null) reader.Close();
                if (stream != null) stream.Close();
                if (rsp != null) rsp.Close();
            }
        }