How to convert array of byte to original file (to provide download of file) - asp.net

Question

I m using Opendialogbox to read the file. Then stored the file in byte[] array.
file --> byte []
byte[] --> stored on SQL AZure in varbinary(max) field.
Here is my code:
OpenFileDialog ofd = new OpenFileDialog();
if ((bool)ofd.ShowDialog())
{
FileStream fileStream = ofd.File.OpenRead());
byte[] buffer = new byte[fileStream.Length];
int read = 0;
using (BinaryReader binaryReader = new BinaryReader(fileStream))
{
do
{
read = binaryReader.Read(buffer, 0, Convert.ToInt32(fileStream.Length));
// Stored the File in byte[] Array buffer
} while (read > 0);
}
}
Now I want to convert this byte array to the original file (like .doc,.txt,jpeg). i know the extension in which file is to be convert.
SQL AZure ---> byte[] // done
byte[] ---> to original file. // Problem
Please give solution to download the file.

Answer 1

One way - not necessarily the best - is as follows:
using (MemoryStream ms = new MemoryStream(theBytes))
{
using (FileStream fs = new FileStream(string.Format("C:\\tempfile.{0}", theExtension)))
{
ms.WriteTo(fs);
}
}

Answer 2

namespace FileSaveDialogDemo
{
public partial class MainPage : UserControl
{
#region Fields
SaveFileDialog dialog= new SaveFileDialog();
#endregion
#region Constructors
public MainPage()
{
InitializeComponent();
this.dialog = new SaveFileDialog();
try
{
this.dialog.DefaultExt = ".txt";
this.dialog.Filter = "Text Files|*.txt|Log Files|*.log|All Files|*.*";
this.dialog.FilterIndex = 2;
}
catch ( Exception ex )
{
this.tblError.Text = "Error configuring SaveFileDialog: " + ex.Message;
}
}
#endregion
private void btnSaveFile_Click( object sender, RoutedEventArgs e )
{
bool? dialogResult = this.dialog.ShowDialog();
if ( dialogResult == true )
{
try
{
byte[] fileBytes; // your varbinary file from database
using (Stream fs = (Stream)dialog.OpenFile())
{
fs.Write(fileBytes, 0, fileBytes.Length);
fs.Close();
lblMsg.Content = "File successfully saved!";
}
}
catch ( Exception ex )
{
this.tblError.Text = "Error calling service: " + ex.Message;
}
}
} // End of Function
}// End of MainPage class
}

Answer 3

It seems the issue you have has probably nothing to do with saving a binary file; it is more likely a basic security issue. Try saving to a path on which you have programmatic write access. For example, try saving to your My Documents directory instead of C:. Try using the Environment.SpecialFolder enumeration like this, and append the file name + extension.
Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)
You have a number of other ways to work around this issue, including starting Visual Studio in Elevated Mode (run as Administrator), and/or allow "Everyone" write access to your C:\ drive. But I wouldn't recommend these techniques necessarily; consider saving to a folder where the security settings are lower than c:\, such as My Documents.