利用HttpWebRequest模拟提交图片

 /// <summary>
    /// Post发送图片数据
    /// </summary>
    public Queusresult requestData(string uri, string imgUrl, List<dataModes> ListMode, Encoding en, CookieContainer cook)
    {
        HttpWebRequest req = WebRequest.Create(uri) as HttpWebRequest;
        req.Method = "POST";
        req.ContentType = "application/octet-stream";
　　　　 //一些不需要的请求头 如果去掉不影响久尽量去掉
        // req.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        req.CookieContainer = cook;
        req.AllowAutoRedirect = true;
        
　　　　　//可能post了其他参数需要跟图片拼接，我这里没有 所以注释了
        //StringBuilder postData = new StringBuilder("");
        //foreach (dataModes m in ListMode)
        //{
        //    postData.AppendFormat("{0}={1}&", m.keys, m.values);
        //}
        //postData.AppendFormat("{0}={1}", "1", "1");
        //Byte[] writData = ASCIIEncoding.ASCII.GetBytes(postData.ToString());

        //读取图片
        FileStream oStream = new FileStream(imgUrl, FileMode.Open, FileAccess.Read);
        BinaryReader oReader = new BinaryReader(oStream);
        Byte[] imgData = oReader.ReadBytes(Convert.ToInt32(oStream.Length));

        //byte[] data3 = new byte[writData.Length + imgData.Length];
        //System.Array.Copy(writData, 0, data3, 0, writData.Length);
        //System.Array.Copy(imgData, 0, data3, writData.Length, imgData.Length);

        req.ContentLength = imgData.Length;
        Stream stream = req.GetRequestStream();
        stream.Write(imgData, 0, imgData.Length);
        stream.Close();

        HttpWebResponse response = req.GetResponse() as HttpWebResponse;
        Stream str = response.GetResponseStream();
        string html = "";
        using (StreamReader strRead = new StreamReader(str, en))
        {
            req.CookieContainer.Add(response.Cookies);
            html = strRead.ReadToEnd();
        }
        Queusresult q = new Queusresult();
        q.html = html;
        q.cookie = cook;
        return q;