c# http post get

   public static string HttpGet(string Url, string postDataStr)
        {
            HttpWebRequest request =
                (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr);
            request.Method = "GET";
            request.ContentType = "text/html;charset=UTF-8";

            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;
        }

        public static string HttpPost(string Url, string postDataStr)
        {

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
            request.Method = "POST";
            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;

        }

public static string Post(string url, Dictionary<string, string> dic, string token)
{
string result = "";
HttpWebRequest req = (HttpWebRequest) WebRequest.Create(url);
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
if (!string.IsNullOrEmpty(token)) req.Headers.Add("Principal", token);

#region 添加Post 参数

StringBuilder builder = new StringBuilder();
int i = 0;
foreach (var item in dic)
{
if (i > 0)
builder.Append("&");
builder.AppendFormat("{0}={1}", item.Key, item.Value);
i++;
}

byte[] data = Encoding.UTF8.GetBytes(builder.ToString());
req.ContentLength = data.Length;
using (Stream reqStream = req.GetRequestStream())
{
reqStream.Write(data, 0, data.Length);
reqStream.Close();
}

#endregion

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;
}