下载远程图片到服务端

string url= Fetch.GetString("codeurl");

string fullname = HttpContext.Current.Request.MapPath("qrcode.jpg");

public bool downloadfile(string dowloadurl, string savefullname)
    {
        bool flagdown = false;
        // System.Net.HttpWebRequest httpWebRequest = null;
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(dowloadurl);
        WebResponse response = request.GetResponse();
        Stream stream = response.GetResponseStream();
        try
        {
            if (!response.ContentType.ToLower().StartsWith("text/"))
            {
                //Value = SaveBinaryFile(response, FileName); 
                byte[] buffer = new byte[1024];
                Stream outStream = System.IO.File.Create(savefullname);
                Stream inStream = response.GetResponseStream();

                int l;
                do
                {
                    l = inStream.Read(buffer, 0, buffer.Length);
                    if (l > 0)
                        outStream.Write(buffer, 0, l);
                }
                while (l > 0);

                outStream.Close();
                inStream.Close();
            }
            flagdown = true;
        }
        catch (System.Exception ex)
        {
            Response.Write(ex.ToString());
        }
        return flagdown;
    }