C# post提交表单的例程

protected string GetWebContent(string url)
    {
        Stream outstream = null;
        Stream instream = null;
        StreamReader sr = null;
        HttpWebResponse response = null;
        HttpWebRequest request = null;
        // 要注意的这是这个编码方式，还有内容的Xml内容的编码方式
        Encoding encoding = Encoding.GetEncoding("GBK");
        byte[] data = encoding.GetBytes(url);

        // 准备请求,设置参数
        request = WebRequest.Create(url) as HttpWebRequest;
        request.Method = "POST";
        //request.ContentType = "text/plain";
        request.ContentLength = data.Length;

        outstream = request.GetRequestStream();
        outstream.Write(data, 0, data.Length);
        outstream.Flush();
        outstream.Close();
        //发送请求并获取相应回应数据

        response = request.GetResponse() as HttpWebResponse;
        //直到request.GetResponse()程序才开始向目标网页发送Post请求
        instream = response.GetResponseStream();
        sr = new StreamReader(instream, encoding);
        //返回结果网页(html)代码

        string content = sr.ReadToEnd();
        return content;
    }