private void CleanupTwain()
{
if (_twain.State == 4)
{
_twain.CurrentSource.Close();
}
if (_twain.State == 3)
{
_twain.Close();
}
if (_twain.State > 2)
{
// normal close down didn't work, do hard kill
_twain.ForceStepDown(2);
}
}
private void InternalScan(TwainImpl twainImpl, IWin32Window dialogParent, ScanDevice scanDevice, ScanProfile scanProfile, ScanParams scanParams,
CancellationToken cancelToken, ScannedImageSource.Concrete source, Action <ScannedImage, ScanParams, string> runBackgroundOcr)
{
if (dialogParent == null)
{
dialogParent = new BackgroundForm();
}
if (twainImpl == TwainImpl.Legacy)
{
Legacy.TwainApi.Scan(scanProfile, scanDevice, dialogParent, formFactory, source);
return;
}
PlatformInfo.Current.PreferNewDSM = twainImpl != TwainImpl.OldDsm;
var session = new TwainSession(TwainAppId);
var twainForm = Invoker.Current.InvokeGet(() => scanParams.NoUI ? null : formFactory.Create <FTwainGui>());
Exception error = null;
bool cancel = false;
DataSource ds = null;
var waitHandle = new AutoResetEvent(false);
int pageNumber = 0;
session.TransferReady += (sender, eventArgs) =>
{
Debug.WriteLine("NAPS2.TW - TransferReady");
if (cancel)
{
eventArgs.CancelAll = true;
}
};
session.DataTransferred += (sender, eventArgs) =>
{
try
{
Debug.WriteLine("NAPS2.TW - DataTransferred");
pageNumber++;
using (var output = twainImpl == TwainImpl.MemXfer
? GetBitmapFromMemXFer(eventArgs.MemoryData, eventArgs.ImageInfo)
: Image.FromStream(eventArgs.GetNativeImageStream()))
{
using (var result = scannedImageHelper.PostProcessStep1(output, scanProfile))
{
if (blankDetector.ExcludePage(result, scanProfile))
{
return;
}
var bitDepth = output.PixelFormat == PixelFormat.Format1bppIndexed
? ScanBitDepth.BlackWhite
: ScanBitDepth.C24Bit;
var image = new ScannedImage(result, bitDepth, scanProfile.MaxQuality, scanProfile.Quality);
if (scanParams.DetectPatchCodes)
{
foreach (var patchCodeInfo in eventArgs.GetExtImageInfo(ExtendedImageInfo.PatchCode))
{
if (patchCodeInfo.ReturnCode == ReturnCode.Success)
{
image.PatchCode = GetPatchCode(patchCodeInfo);
}
}
}
scannedImageHelper.PostProcessStep2(image, result, scanProfile, scanParams, pageNumber);
string tempPath = scannedImageHelper.SaveForBackgroundOcr(result, scanParams);
runBackgroundOcr(image, scanParams, tempPath);
source.Put(image);
}
}
}
catch (Exception ex)
{
Debug.WriteLine("NAPS2.TW - DataTransferred - Error");
error = ex;
cancel = true;
StopTwain();
}
};
session.TransferError += (sender, eventArgs) =>
{
Debug.WriteLine("NAPS2.TW - TransferError");
if (eventArgs.Exception != null)
{
error = eventArgs.Exception;
}
else if (eventArgs.SourceStatus != null)
{
Log.Error("TWAIN Transfer Error. Return code = {0}; condition code = {1}; data = {2}.",
eventArgs.ReturnCode, eventArgs.SourceStatus.ConditionCode, eventArgs.SourceStatus.Data);
}
else
{
Log.Error("TWAIN Transfer Error. Return code = {0}.", eventArgs.ReturnCode);
}
cancel = true;
StopTwain();
};
session.SourceDisabled += (sender, eventArgs) =>
{
Debug.WriteLine("NAPS2.TW - SourceDisabled");
StopTwain();
};
void StopTwain()
{
waitHandle.Set();
if (!scanParams.NoUI)
{
Invoker.Current.Invoke(() => twainForm.Close());
}
}
void InitTwain()
{
try
{
var windowHandle = (Invoker.Current as Form)?.Handle;
ReturnCode rc = windowHandle != null?session.Open(new WindowsFormsMessageLoopHook(windowHandle.Value)) : session.Open();
if (rc != ReturnCode.Success)
{
Debug.WriteLine("NAPS2.TW - Could not open session - {0}", rc);
StopTwain();
return;
}
ds = session.FirstOrDefault(x => x.Name == scanDevice.ID);
if (ds == null)
{
Debug.WriteLine("NAPS2.TW - Could not find DS - DS count = {0}", session.Count());
throw new DeviceNotFoundException();
}
rc = ds.Open();
if (rc != ReturnCode.Success)
{
Debug.WriteLine("NAPS2.TW - Could not open DS - {0}", rc);
StopTwain();
return;
}
ConfigureDS(ds, scanProfile, scanParams);
var ui = scanProfile.UseNativeUI ? SourceEnableMode.ShowUI : SourceEnableMode.NoUI;
Debug.WriteLine("NAPS2.TW - Enabling DS");
rc = scanParams.NoUI ? ds.Enable(ui, true, windowHandle ?? IntPtr.Zero) : ds.Enable(ui, true, twainForm.Handle);
Debug.WriteLine("NAPS2.TW - Enable finished");
if (rc != ReturnCode.Success)
{
Debug.WriteLine("NAPS2.TW - Enable failed - {0}, rc");
StopTwain();
}
else
{
cancelToken.Register(() =>
{
Debug.WriteLine("NAPS2.TW - User Cancel");
cancel = true;
session.ForceStepDown(5);
});
}
}
catch (Exception ex)
{
Debug.WriteLine("NAPS2.TW - Error");
error = ex;
StopTwain();
}
}
if (!scanParams.NoUI)
{
twainForm.Shown += (sender, eventArgs) => { InitTwain(); };
twainForm.Closed += (sender, args) => waitHandle.Set();
}
if (scanParams.NoUI)
{
Debug.WriteLine("NAPS2.TW - Init with no form");
Invoker.Current.Invoke(InitTwain);
}
else if (!scanParams.Modal)
{
Debug.WriteLine("NAPS2.TW - Init with non-modal form");
Invoker.Current.Invoke(() => twainForm.Show(dialogParent));
}
else
{
Debug.WriteLine("NAPS2.TW - Init with modal form");
Invoker.Current.Invoke(() => twainForm.ShowDialog(dialogParent));
}
waitHandle.WaitOne();
Debug.WriteLine("NAPS2.TW - Operation complete");
if (ds != null && session.IsSourceOpen)
{
Debug.WriteLine("NAPS2.TW - Closing DS");
ds.Close();
}
if (session.IsDsmOpen)
{
Debug.WriteLine("NAPS2.TW - Closing session");
session.Close();
}
if (error != null)
{
Debug.WriteLine("NAPS2.TW - Throwing error - {0}", error);
if (error is ScanDriverException)
{
throw error;
}
throw new ScanDriverUnknownException(error);
}
}