HttpWebRequest请求时无法发送具有此谓词类型的内容正文。

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(postUrl); //--需要封装的参数

            request.CookieContainer = new CookieContainer();

            CookieContainer cookie = request.CookieContainer;//如果用不到Cookie，删去即可

            //以下是发送的http头

            request.Referer = "";

            request.Accept = "Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";

            request.Headers["Accept-Language"] = "zh-CN,zh;q=0.";

            request.Headers["Accept-Charset"] = "GBK,utf-8;q=0.7,*;q=0.3";

            request.UserAgent = "User-Agent:Mozilla/5.0 (Windows NT 5.1) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.202 Safari/535.1";

            request.KeepAlive = true;

            //上面的http头看情况而定，但是下面俩必须加

            request.ContentType = "application/x-www-form-urlencoded";

            Encoding encoding = Encoding.UTF8;//根据网站的编码自定义

            request.Method ="get";  //--需要将get改为post才可行

            string postDataStr;

            Stream requestStream = request.GetRequestStream();

            if (postDatas != "")

            {

                postDataStr=postDatas;//--需要封装,形式如“arg=arg1&arg2=arg2”

                byte[] postData = encoding.GetBytes(postDataStr);//postDataStr即为发送的数据，

                request.ContentLength = postData.Length;

                requestStream.Write(postData, 0, postData.Length);

            }

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            Stream responseStream = response.GetResponseStream();

            StreamReader streamReader = new StreamReader(responseStream, encoding);

            string retString = streamReader.ReadToEnd();

            streamReader.Close();

            responseStream.Close();

            return retString;

　　如果是以流的方式提交表单数据的时候不能使用get方法，必须用post方法，

改为

request.Method ="post";  就可以了。  做一个记号