Here's some code extracted from appdev courseware (
www.appdev.com)
that was written by Andy Baron, Ken Getz and myself. When you're
working with blobs that originated in Access, you have to strip off
the header info that Access uses for OLE fields. This sample was
designed for a windows form and works with SQLS Northwind, but the
concept is the same -- you have to stream in the data and strip off
those header bytes before you can use the image for anything. I can
probably dig up the VB code from somewhere if you can't figure out the
C#.
--mary
private void LoadEmployeePho to(int employeeID)
{
SqlDataAdapter da = null;
DataTable dt = new DataTable();
string strCnn =
"Data Source=(local); Database=Northw ind;"
+ "Integrated Security=SSPI";
string strSQL =
"SELECT Photo FROM dbo.Employees"
+ " WHERE EmployeeID = "
+ employeeID.ToSt ring();
MemoryStream msPic;
// Signature bytes of an
// OLE container header.
const byte OLEbyte0 = 21;
const byte OLEbyte1 = 28;
// Number of bytes in
// an OLE container header.
const int OLEheaderLength = 78;
da = new SqlDataAdapter( strSQL, strCnn);
da.Fill(dt);
if (dt.Rows.Count == 0)
return;
// Move binary picture data into the byte array
byte[] abytPic = (byte[])dt.Rows[0]["Photo"];
// Test for an OLE container header
if ((abytPic[0] == OLEbyte0)
&& (abytPic[1] == OLEbyte1))
{
// Use a second array to strip off the header.
// Make it big enough to hold
// the bytes after the header.
byte[] abytStripped =
new byte[abytPic.Length - OLEheaderLength];
// Strip off the header by copying the bytes
// after the header.
System.Buffer.B lockCopy(
abytPic, OLEheaderLength , abytStripped,
0, abytPic.Length - OLEheaderLength );
// Load the new byte array
// into a MemoryStream.
msPic = new MemoryStream(ab ytStripped);
}
else
{
// Load the original byte array into a MemoryStream
msPic = new MemoryStream(ab ytPic);
}
// Set the picture box image, using the stream.
picEmployee.Ima ge = Image.FromStrea m(msPic);
}
On Wed, 14 Apr 2004 14:16:06 -0700, Bob <Az*****@cox.ne t> wrote:
I'm looking for an example of how to extract images from an Access 97 blob into an asp datagrid. Anybody have examples?
