how to convert byte arry to its original file (when downloading file)

Question

3.00/5 (1 vote)

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I Developed an application for Uploading Files and Downloading Files,
I used database to store my document file in which, Documents are stored in
Byte array,

Now i am unable to convert back that byte array into its original file format.

can any one help me to solve out this problem?

i tried following code for download:

C#

{
  HttpContext.Current.Response.Clear();
  HttpContext.Current.Response.AddHeader("Content-Disposition",     
     "attachment; filename=" + fileName);
  HttpContext.Current.Response.AddHeader("Content-Length",   
     Convert.ToString(value.Length));
  HttpContext.Current.Response.ContentType = "application/octet-stream";
  HttpContext.Current.Response.Write(value);
  HttpContext.Current.Response.End();}

help me if any one get any idea!!!

Posted 24-Aug-11 21:13pm

Tushar Parmar

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Comments

Timberbird 25-Aug-11 3:18am

How do you upload file? Do you read bytes from stream or converting base64 to byte array?

3 solutions

Solution 1

Don't use Response.Write, use Response.BinaryWrite instead.

The way I handle it is to use an ASPX file:

C#

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="wm5ftdl.aspx.cs" Inherits="wm5ftdl" %>

<%
    // Send a download file to the client given the filename.
    string guid = Request.QueryString["file"];
    string fileName = "ERROR";
    byte[] data = new byte[] { 0, 0, 0, 0 };
    string strCon = System.Web.Configuration.WebConfigurationManager.ConnectionStrings["DownloadDatabase"].ConnectionString;
    using (System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection(strCon))
        {
        con.Open();
        string strcmd = "SELECT [iD] ,cn.[fileName],[description] ,[dataContent] ,[version] " +
                        "FROM dlContent cn " +

                        "WHERE cn.iD=@ID";
        using (System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand(strcmd, con))
            {
            cmd.Parameters.AddWithValue("@ID", guid);
            using (System.Data.SqlClient.SqlDataReader r = cmd.ExecuteReader())
                {
                if (r.Read())
                    {
                    fileName = (string) r["filename"];
                    data = (byte[]) r["dataContent"];
                    }
                }
            }
        }
    Response.Clear();
    Response.AddHeader("Cache-Control", "no-cache, must-revalidate, post-check=0, pre-check=0");
    Response.AddHeader("Pragma", "no-cache");
    Response.AddHeader("Content-Description", "File Download");
    Response.AddHeader("Content-Type", "application/force-download");
    Response.AddHeader("Content-Transfer-Encoding", "binary\n");
    Response.AddHeader("content-disposition", "attachment;filename=" + fileName);
    Response.BinaryWrite(data);
    Response.End();
%>

Posted 24-Aug-11 21:18pm

OriginalGriff

Comments

Carmineeeeee 5-Sep-18 8:47am

Hi,

how can I solve if I do not know the name and especially the file extension?

Thanks

Solution 2

Hi OriginalGriff,

when i puts Response.BinaryWrite,
it works same as Response.Write and
again it give wrong format of data

and gives "System Bytes[]" as output when i opens it with notepad.

Regards,
tushar

Posted 24-Aug-11 21:34pm

Tushar Parmar

Comments

Timberbird 25-Aug-11 4:26am

Er... do you attempt to initialize your value in a way like value = myBinaryData.ToString();?

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Tushar Parmar · Accepted Answer · 2011-08-25T04:15:00

I got Solution of this problem using following code:

C#

HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ContentType = "application/octet-stream";
            HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=\"" + FileName + "\"");
            HttpContext.Current.Response.AddHeader("Content-Length", Convert.ToString(Content.Length));
            HttpContext.Current.Response.BinaryWrite(Content);
            HttpContext.Current.Response.End();

and i set data type of file to binary.

thank you all for help!!!

how to convert byte arry to its original file (when downloading file)

3 solutions

Solution 1

Solution 2

Solution 3

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