.NET get、post 请求

/**////url:Post请求的URL地址
///param:需要传递的参数，例如：a=2&b=3.可以为""空字符串
///timeOut:Post请求超时时间
///encoding:Post请求的编码,例如：Encoding.UTF8
///contentType:Post请求的类型

public static string HttpPost(string url, string param, int timeOut, Encoding encoding,string contentType="")
        ...{
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method = "POST";
            request.ContentType =string.IsNullOrEmpty(contentType)? "application/x-www-form-urlencoded":contentType;
            request.Accept = "*/*";
            request.Timeout = 1000 * timeOut;
            request.AllowAutoRedirect = false;

            StreamWriter requestStream = null;
            WebResponse response = null;
            string responseStr = null;

            try
            ...{
                requestStream = new StreamWriter(request.GetRequestStream());
                requestStream.Write(param);
                requestStream.Close();

                response = request.GetResponse();
                if (response != null)
                ...{
                    StreamReader reader = new StreamReader(response.GetResponseStream(), encoding);
                    responseStr = reader.ReadToEnd();
                    reader.Close();
                }
            }
            catch (Exception)
            ...{
                throw;
            }
            finally
            ...{
                request = null;
                requestStream = null;
                response = null;
            }

            return responseStr;
        }

		

public static string HttpGet(string url, int timeOut, Encoding encoding)
        ...{
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method = "GET";
            request.ContentType = "application/x-www-form-urlencoded";
            request.Accept = "*/*";
            request.Timeout = 1000 * timeOut;
            request.AllowAutoRedirect = false;

            WebResponse response = null;
            string responseStr = null;

            try
            ...{
                response = request.GetResponse();

                if (response != null)
                ...{
                    StreamReader reader = new StreamReader(response.GetResponseStream(), encoding);
                    responseStr = reader.ReadToEnd();
                    reader.Close();
                }
            }
            catch (Exception)
            ...{
                throw;
            }
            finally
            ...{
                request = null;
                response = null;
            }

            return responseStr;
        }