【转】C#模拟http 发送post或get请求

原文地址：http://www.cnblogs.com/xssxss/archive/2012/07/03/2574554.html

模拟POST Json

public static string PostMoths(string url, string param)
    {
        string strURL = url;
        System.Net.HttpWebRequest request;
        request = (System.Net.HttpWebRequest)WebRequest.Create(strURL);
        request.Method = "POST";
        request.ContentType = "application/json;charset=UTF-8";
        string paraUrlCoded = param;
        byte[] payload;
        payload = System.Text.Encoding.UTF8.GetBytes(paraUrlCoded);
        request.ContentLength = payload.Length;
        Stream writer = request.GetRequestStream();
        writer.Write(payload, 0, payload.Length);
        writer.Close();
        System.Net.HttpWebResponse response;
        response = (System.Net.HttpWebResponse)request.GetResponse();
        System.IO.Stream s;
        s = response.GetResponseStream();
        string StrDate = "";
        string strValue = "";
        StreamReader Reader = new StreamReader(s, Encoding.UTF8);
        while ((StrDate = Reader.ReadLine()) != null)
        {
            strValue += StrDate + "
";
        }
        return strValue;
    }

private string HttpPost(string Url, string postDataStr)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.ContentLength = Encoding.UTF8.GetByteCount(postDataStr);
            request.CookieContainer = cookie;
            Stream myRequestStream = request.GetRequestStream();
            StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312"));
            myStreamWriter.Write(postDataStr);
            myStreamWriter.Close();
 
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 
            response.Cookies = cookie.GetCookies(response.ResponseUri);
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            string retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();
 
            return retString;
        }
 
        public 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.GetEncoding("utf-8"));
            string retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();
 
            return retString;
        }

在post的时候有时也用的到cookie，像登录163发邮件时候就需要发送cookie，所以在外部一个cookie属性随时保存 CookieContainer cookie = new CookieContainer();

！注意：有时候请求会重定向，但我们就需要从重定向url获取东西，像QQ登录成功后获取sid，但上面的会自动根据重定向地址跳转。我们可以用:
request.AllowAutoRedirect = false;设置重定向禁用，你就可以从headers的Location属性中获取重定向地址