I'm working on redeveloping an Access based system into c#.net, however when MS went from office 2003 to office 2007 they removed the picture editor within access - which meant that previously stored pictures would no longer display in the system. The guys at the company did a hack that basically saved the images with VBA using excel in the background (I can get more information if you need it) but basically it meant the access image controls could still be used (Object bound frames).
However, I now have the problem of trying to display these in .NET applications, and after countless days of trying different ways of manipulating the byte array I'm close to giving up. I have tried at least 8 different suggested solutions and each one ends with a 'Parameter not recognised' exception when doing Image.fromStream(). Below is the code which has got me the closest so far:
private void imageExtractTest()
{
LogOnDataSetTableAdapters.QueriesTableAdapter qa =
new LogOnDataSetTableAdapters.QueriesTableAdapter();
object docO = qa.GetLogonImage();
if (docO == null || !(docO is byte[]))
{
return;
}
byte[] doc = (byte[])docO;
MemoryStream ms = new MemoryStream();
ms.Write(doc, 0, doc.Length);
int firstByte;
int secondByte;
ms.Seek(0, SeekOrigin.Begin);
firstByte = ms.ReadByte();
secondByte = ms.ReadByte();
if (firstByte != 0x15 && secondByte != 0x1C)
{
//ErrorResponse("Stored object is not an Access File.");
return;
}
int fileTypeLoc = 20; // begin of the file type
short offset; // end of the file type
byte[] buffer = new byte[2];
ms.Read(buffer, 0, 2);
offset = BitConverter.ToInt16(buffer, 0);
long seekTotal = 0;
seekTotal += offset;
string docType = String.Empty;
for (int i = fileTypeLoc; i < offset; i++)
{
docType += (char)doc[i];
}
//if I query docType now I get 'Picture'
// magic eight bytes 01 05 00 00 03 00 00 00
ms.Seek(seekTotal, SeekOrigin.Begin);
buffer = new byte[8];
ms.Read(buffer, 0, 8);
seekTotal += 8;
// Second offset to move to
buffer = new byte[4];
ms.Read(buffer, 0, 4);
seekTotal += 4;
long offset2 = BitConverter.ToInt32(buffer, 0);
seekTotal += offset2;
ms.Seek(seekTotal, SeekOrigin.Begin);
// eight empty bytes
buffer = new byte[8];
ms.Read(buffer, 0, 8);
seekTotal += 8;
// next n bytes are the length of the file
buffer = new byte[4];
ms.Read(buffer, 0, 4);
seekTotal += 4;
long fileByteLength = BitConverter.ToInt32(buffer, 0);
// next N bytes are the file
byte[] data = new byte[fileByteLength];
// store file bytes in data buffer
ms.Read(data, 0, Convert.ToInt32(fileByteLength));
MemoryStream imageStream = new MemoryStream(data);
Image test = Image.FromStream(imageStream);
}
This code was adapted from here, I didn't need the various doctypes identification as I'm only dealing with images, however the image type could be any number of things - jpg, bmp, gif, png etc.
I've also tried saving the outputted byte array but I've had no luck viewing that either. But when I point access to the database and get it to view it, everything is fine. Also the .NET Crystal Report designer is able to get these images some how - so they must be in there somewhere...
Has anyone got any ideas?
Marlon
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