How do I fetch a bmp from a BLOB and save it as a file?

[Joakim Olesen]

Hi

I have a table with a BLOB column which contains bmp images. I'm
unsuccessfully trying to fetch one of these images and saving it as a file.
The result is a file with a size of 12Kb, but it's not a valid BMP file (I
can't view it in an image viewer). The image I try to fetch is quite small
though, so the size (12Kb) is sensible. I've pasted my code below (and it
doesn't throw any exception):

using System;
using System.Data.SqlClient;
using System.IO;
using System.Text;
using System.Data;

namespace ConsoleApplication3
{
class Class1
{

[STAThread]
static void Main(string[] args)
{
SqlConnection Conn = new SqlConnection();
Conn.ConnectionString = "Here I put my connection string";
Conn.Open();

SqlCommand Comm = new SqlCommand("SELECT Picture FROM TableName WHERE
Name='John'", Conn);

BinaryWriter bw = new BinaryWriter(new FileStream(@"C:\Temp\Picture_" +
System.DateTime.Now.Hour.ToString() + "_" +
System.DateTime.Now.Minute.ToString() + "_" +
System.DateTime.Now.Second.ToString() + ".bmp", System.IO.FileMode.Create));
bw.Write((byte[])Comm.ExecuteScalar());
bw.Close();
Conn.Close();
}
}
}


I hope you can help me with this!

Joakim

 

[Adrian]

Hi!
Try this:
reader = Comm.ExecuteReader();

if (reader.read())

{

System.IO.MemoryStream ms = new
System.IO.MemoryStream((byte[])reader["Scan"]);

Bitmap bm = new Bitmap(ms);

bm.Save(your_filename);

}



Hope that helps.

Best regards.

 

[Joakim Olesen]

It turned out that my code was correct, but that the software that managed
the database automatically compressed the data in the BLOB column. After
disabling that compression, it worked fine.