webrequest post

private static string HttpPost()

{

    string postData="username=中文&userid=838 jdkkd";//在发送的内容里包括中文和空格

    string Web=@"http://www.myweb.com/myresponse.asp";//地址

    postData=postData.Replace(" ","%20");//替换空格

    try

    {

                //获取URL并进行发送字串

                HttpWebRequest myHttpWebRequest =(HttpWebRequest)WebRequest.Create(Web);

                

                Stream myStream=new MemoryStream ();//定义这个Stream是只是为了得到发送字串 经过编码之后得到的

byte的长度。

                StreamWriter myStreamWriter=new StreamWriter(myStream,Encoding.Default);//用默认编码 得到

Stream

                myStreamWriter.Write(postData);

                myStreamWriter.Flush();

                long len=myStream.Length;//目的完成

                myStreamWriter.Close();

                

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

                myHttpWebRequest.ContentLength=len;//如果字符串中存在中文 使用postData.Length得到长度和编码之

//后的长度是不一样的:(

                myHttpWebRequest.Method="POST";

                Stream newStream=myHttpWebRequest.GetRequestStream();

                myStreamWriter=new StreamWriter(newStream,Encoding.Default);//编码使用Encoding.Default 换来换去编码方法 还是用它得到的中文不会出现乱码,特别是把request("")得到的值写入sql数据库的时候 真是奇怪^O^

                myStreamWriter.Write(postData);

                myStreamWriter.Close();

                //获取本次的回馈,先创建接收回馈的类HTTPWEBRESPONSE

                HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();

                //创建接收回馈的字节流类

                Stream receiveStream = myHttpWebResponse.GetResponseStream();//得到回写的字节流 做爬虫的基础？？？

                Encoding encode = System.Text.Encoding.Default;

                StreamReader readStream = new StreamReader( receiveStream, encode );

                readStream.Close();

                return "";

                            

            }

            catch(Exception e)

            {

                return "";

            }