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From: Tom G. on 1 Mar 2008 11:59
I am working on a project right now that needs to be able to scan in
multiple pages using a scanner's multi feed feature. The scanner
that
I am using to test is Fujitsu fi-5120C.

I am coding this project in C# and am trying to use WIA Automation
2.0
Library. I am open to alternative technologies if someone has any
suggestions.


My test case is that I have three sheets of paper in the document
feeder and I want my code to scan in all three pages at once.


All the pages get scanned correctly when I call the following code:


private void CallScanWizard()
{


WIA.CommonDialog dlg = new WIA.CommonDialog();


Device dvc =
dlg.ShowSelectDevice(WiaDeviceType.ScannerDeviceType,true,false);


if (dvc != null)
{
dlg.ShowAcquisitionWizard(dvc);
}
}


This tells me that it is possible in WIA. However, this can't be the
solution for me. I don't want the user to have to pick a file path
for the images to be saved to. I want to work with them in memory
only.


So I tried the following code:


private const int WIA_DPS_DOCUMENT_HANDLING_SELECT_FEEDER = 1;
private const int WIA_DPS_DOCUMENT_HANDLING_SELECT_FLATBED =
2;
private const int WIA_IPS_PAGES = 3096;


private const int WIA_DPS_DOCUMENT_HANDLING_STATUS_FEED_READY
= 1;


private const int WIA_PROPERTIES_WIA_RESERVED_FOR_NEW_PROPS =
1024;
private const int WIA_PROPERTIES_WIA_DIP_FIRST = 2;
private const int WIA_PROPERTIES_WIA_DPA_FIRST =
WIA_PROPERTIES_WIA_DIP_FIRST +
WIA_PROPERTIES_WIA_RESERVED_FOR_NEW_PROPS;
private const int WIA_PROPERTIES_WIA_DPC_FIRST =
WIA_PROPERTIES_WIA_DPA_FIRST +
WIA_PROPERTIES_WIA_RESERVED_FOR_NEW_PROPS;


private const int WIA_PROPERTIES_WIA_DPS_FIRST =
WIA_PROPERTIES_WIA_DPC_FIRST +
WIA_PROPERTIES_WIA_RESERVED_FOR_NEW_PROPS;
private const int
WIA_PROPERTIES_WIA_DPS_DOCUMENT_HANDLING_STATUS =
WIA_PROPERTIES_WIA_DPS_FIRST + 13;
private const int
WIA_PROPERTIES_WIA_DPS_DOCUMENT_HANDLING_SELECT =
WIA_PROPERTIES_WIA_DPS_FIRST + 14;
private const string WIA_DPS_DOCUMENT_HANDLING_STATUS_STR =
"Document Handling Status";


private const double WIA_ERRORS_BASE_VAL_WIA_ERROR =
2149646336;
private const double WIA_ERRORS_WIA_ERROR_PAPER_EMPTY =
WIA_ERRORS_BASE_VAL_WIA_ERROR + 3;


private const int WIA_IPS_CUR_INTENT = 6146;
private const int WIA_IPS_XRES = 6147;
private const int WIA_IPS_YRES = 6148;


private const int WIA_INTENT_NONE = 0x00000000;
private const int WIA_INTENT_IMAGE_TYPE_COLOR = 0x00000001;
private const int WIA_INTENT_IMAGE_TYPE_GRAYSCALE =
0x00000002;
private const int WIA_INTENT_IMAGE_TYPE_TEXT = 0x00000004;
private const int WIA_INTENT_IMAGE_TYPE_MASK = 0x0000000F;
private const int WIA_INTENT_MINIMIZE_SIZE = 0x00010000;
private const int WIA_INTENT_MAXIMIZE_QUALITY = 0x00020000;
private const int WIA_INTENT_BEST_PREVIEW = 0x00040000;
private const int WIA_INTENT_SIZE_MASK = 0x000F0000;
private const int FEED_READY = 0x01;


private const string wiaFormatPNG =
"{B96B3CAF-0728-11D3-9D7B-0000F81EF32E}";
private void TestScan()
{
DeviceManager manager = new DeviceManager();
object index = 1;


DeviceInfo info = manager.DeviceInfos.get_Item(ref
index);
Device dvc = info.Connect();
object res = 150;
object intent = WIA_INTENT_IMAGE_TYPE_COLOR;
object statusProp = WIA_DPS_DOCUMENT_HANDLING_STATUS_STR;
int documentStatus = 0;
object pgs = 0;
object handler = WIA_DPS_DOCUMENT_HANDLING_SELECT_FEEDER;


foreach (Property p in dvc.Properties)
{
switch (p.PropertyID)
{
case
WIA_PROPERTIES_WIA_DPS_DOCUMENT_HANDLING_SELECT:
p.set_Value(ref handler);
break;


case WIA_IPS_XRES:
case WIA_IPS_YRES:
p.set_Value(ref res);
break;


case WIA_IPS_CUR_INTENT:
p.set_Value(ref intent);
break;


case
WIA_PROPERTIES_WIA_DPS_DOCUMENT_HANDLING_STATUS:
documentStatus = (int)p.get_Value();
break;


case WIA_IPS_PAGES:
p.set_Value(ref pgs);
break;
}
}


foreach (Item itm in dvc.Items)
{
while ((documentStatus & FEED_READY) == FEED_READY)
{
itm.Transfer(wiaFormatPNG);
documentStatus = (int)dvc.Properties.get_Item(ref
statusProp).get_Value();
}
}
}


I got this code idea from http://www.xtremevbtalk.com/showthread.php?t=288758.
However, the DOCUMENT HANDLING STATUS always stays 5 even when all
the
pages are scanned through. This eventually ends in a com exception
being thrown when all the pages have been scanned. I could just
throw
a try catch around the whole thing but that doesn't seem right to me.
I don't like it.


Does anyone have any suggestions for me? This code needs to work
regardless of what scanner is being used. Is WIA the wrong choice
here? Should I go right to TWAIN code?


Thanks in advance for any help anyone can give me.
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