C# http 发送post或get请求

/// <summary>
        /// 向服务器提交XML数据
        /// </summary>
        /// <param name="url">远程访问的地址</param>
        /// <param name="data">参数</param>
        /// <param name="method">"POST"或者“GET”</param>
        /// <returns>远程页面调用结果</returns>
        public static string PostDataToServer(string url, string data, string method)
        {
            HttpWebRequest request = null;
            request = WebRequest.Create(url) as HttpWebRequest;
            switch (method)
            {
                case "GET":
                    request.Method = "GET";
                    break;
                case "POST":
                    {
                        request.Method = "POST";
                        byte[] bdata = Encoding.UTF8.GetBytes(data);
                        request.ContentType = "application/xml;charset=utf-8";
                        request.ContentLength = bdata.Length;
                        Stream streamOut = request.GetRequestStream();
                        streamOut.Write(bdata, 0, bdata.Length);
                        streamOut.Close();
                    }
                    break;
            }
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream streamIn = response.GetResponseStream();

            StreamReader reader = new StreamReader(streamIn);
            string result = reader.ReadToEnd();
            reader.Close();
            streamIn.Close();
            response.Close();

            return result;
        }

调用：

string url="http://10.1.200.215:2289/aa.ashx";
string data="{
    "request": {
        "body": {
            "ProjectId": 10,
            "OperateType": 3
        },
        "header": {
            "accountID": "erwerwer,
            "digitalSign": 343524543
            "reqTime": "1431048981",
            "serviceName": "ertetre",
            "version": "20150424"
        }
    }
}";
string method="POST";
string res=PostDataToServer(url, data, method);

别的比较好的文章收藏：http://singlepine.cnblogs.com/articles/292661.html；http://www.cnblogs.com/xssxss/archive/2012/07/03/2574554.html