Wednesday, December 1, 2010

File Upload using HTTPWebRequest

img-upload.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="img-upload.aspx.cs" Inherits="img_upload" EnableEventValidation="false"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server" enctype="multipart/form-data">
        <p><input id="uploadFile" type="file" runat="server" /></p>
        <p>
            <input id="txtFileName" type="text" runat="server" />
        </p>
        <p><asp:Button ID="uploadButton" runat="server" Text="Upload" OnClick="uploadButton_Click" /></p>
    </form>
</body>
</html>
 
 
img-upload.aspx.cs
 
 protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            if (uploadFile.PostedFile != null && uploadFile.PostedFile.ContentLength > 0)
            {
                string fileName = Path.GetFileName(uploadFile.PostedFile.FileName);
                string folder = Server.MapPath("~/Files/");
                Directory.CreateDirectory(folder);
                uploadFile.PostedFile.SaveAs(Path.Combine(folder, fileName));
                Response.Write("Uploaded: " + fileName);
            }
            Response.Write("OK: ");
        }
    }
 
Calling Code :
 
   CookieContainer cookies = new CookieContainer();
                            //add or use cookies
                            NameValueCollection querystring = new NameValueCollection();
                            querystring["txtFileName"] = "testfilename";
                            string uploadfile;// set to file to upload
                            uploadfile = @"C:\google.gif";
                            //everything except upload file and url can be left blank if needed
                            string str14 = UploadFileEx(uploadfile,
                                  "http://localhost:8052/img-upload.aspx", "uploadFile", "image/gif",
                                 querystring, cookies);
 
 
public static string UploadFileEx(string uploadfile, string url,
    string fileFormName, string contenttype, NameValueCollection querystring,
    CookieContainer cookies)
        {
            if ((fileFormName == null) ||
                (fileFormName.Length == 0))
            {
                fileFormName = "file";
            }
            if ((contenttype == null) ||
                (contenttype.Length == 0))
            {
                contenttype = "application/octet-stream";
            }

            string postdata;
            postdata = "?";
            if (querystring != null)
            {
                foreach (string key in querystring.Keys)
                {
                    postdata += key + "=" + querystring.Get(key) + "&";
                }
            }
            Uri uri = new Uri(url + postdata);

            string boundary = "----------" + DateTime.Now.Ticks.ToString("x");
            HttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create(uri);
            webrequest.CookieContainer = cookies;
            webrequest.ContentType = "multipart/form-data; boundary=" + boundary;
            webrequest.Method = "POST";

            // Build up the post message header
            StringBuilder sb = new StringBuilder();
            sb.Append("--");
            sb.Append(boundary);
            sb.Append("\r\n");
            sb.Append("Content-Disposition: form-data; name=\"");
            sb.Append(fileFormName);
            sb.Append("\"; filename=\"");
            sb.Append(Path.GetFileName(uploadfile));
            sb.Append("\"");
            sb.Append("\r\n");
            sb.Append("Content-Type: ");
            sb.Append(contenttype);
            sb.Append("\r\n");
            sb.Append("\r\n");
            string postHeader = sb.ToString();
            byte[] postHeaderBytes = Encoding.UTF8.GetBytes(postHeader);
            // Build the trailing boundary string as a byte array
            // ensuring the boundary appears on a line by itself
            byte[] boundaryBytes =
                   Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
            FileStream fileStream = new FileStream(uploadfile,
                                        FileMode.Open, FileAccess.Read);
            long length = postHeaderBytes.Length + fileStream.Length +
                                                   boundaryBytes.Length;
            webrequest.ContentLength = length;
            Stream requestStream = webrequest.GetRequestStream();
            // Write out our post header
            requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);
            // Write out the file contents
            byte[] buffer = new Byte[checked((uint)Math.Min(4096,
                                     (int)fileStream.Length))];
            int bytesRead = 0;
            while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
                requestStream.Write(buffer, 0, bytesRead);
            // Write out the trailing boundary
            requestStream.Write(boundaryBytes, 0, boundaryBytes.Length);
            WebResponse responce = webrequest.GetResponse();
            Stream s = responce.GetResponseStream();
            StreamReader sr = new StreamReader(s);
            return sr.ReadToEnd();
        }
 
 
 

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