protected void TransferPicturesIncremental()
{
// see http://www.twain.org/wp-content/uploads/2017/03/TWAIN-2.4-Specification.pdf
// page 4-20
Console.WriteLine("TransferPicturesIncremental...");
Logger.WriteLog(LOG_LEVEL.LL_NORMAL_LOG, "TransferPicturesIncremental...");
if (DataSource.SourceId.Id == 0)
{
return;
}
PendingXfers pendingTransfer = new PendingXfers();
TwainResult result;
try
{
int recievedBlockCount = 1;
do
{
pendingTransfer.Count = 0; // the Twain source will fill this in during DsPendingTransfer
Console.WriteLine("Get the image info...");
// Get the image info
ImageInfo imageInfo = new ImageInfo();
result = Twain32Native.DsImageInfo(
ApplicationId,
DataSource.SourceId,
DataGroup.Image,
DataArgumentType.ImageInfo,
Message.Get,
imageInfo);
if (result != TwainResult.Success)
{
DataSource.Close();
break;
}
/*Console.WriteLine("Get the image layout...");
* ImageLayout imageLayout = new ImageLayout();
* result = Twain32Native.DsImageLayout(
* ApplicationId,
* DataSource.SourceId,
* DataGroup.Image,
* DataArgumentType.ImageLayout,
* Message.GetCurrent,
* imageLayout);
*
* if (result != TwainResult.Success)
* {
* DataSource.Close();
* break;
* }*/
// Setup Destination Bitmap
Bitmap bitmap = BitmapRenderer.NewBitmapForImageInfo(imageInfo);
Console.WriteLine("Setup incremental Memory XFer...");
// Setup incremental Memory XFer
SetupMemXfer setupMemXfer = new SetupMemXfer();
result = Twain32Native.DsSetupMemXfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Control,
DataArgumentType.SetupMemXfer,
Message.Get,
setupMemXfer
);
if (result != TwainResult.Success)
{
DataSource.Close();
break;
}
Console.WriteLine("allocate the preferred buffer size...");
// allocate the preferred buffer size
// see twain spec pdf, page 4-21
ImageMemXfer imageMemXfer = new ImageMemXfer();
try
{
imageMemXfer.Memory.Flags = MemoryFlags.AppOwns | MemoryFlags.Pointer;
imageMemXfer.Memory.Length = setupMemXfer.MinBufSize; // 對於A8 scanner，Preferred = MaxBufSize，太大了，所以我們選小一點的
imageMemXfer.Memory.TheMem = Kernel32Native.GlobalAlloc(GlobalAllocFlags.MemFixed, (int)setupMemXfer.MinBufSize * 2); // 不知道為什麼原本她size寫要*2倍
imageMemXfer.Compression = Compression.None;
if (imageMemXfer.Memory.TheMem == IntPtr.Zero)
{
Logger.WriteLog(LOG_LEVEL.LL_SERIOUS_ERROR, "error allocating buffer for memory transfer");
throw new TwainException("error allocating buffer for memory transfer");
}
long pixels_written = 0;
long total_pixels = imageInfo.ImageWidth * imageInfo.ImageLength;
do
{
// perform a transfer
result = Twain32Native.DsImageMemXfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Image,
DataArgumentType.ImageMemXfer,
Message.Get,
imageMemXfer
);
//string savePath = @"C:\Users\Tenny\Pictures\TwainTest\tempBitmap_";
//savePath += i.ToString() + @".bmp";
if (result == TwainResult.Success || result == TwainResult.XferDone)
{
// dibArray是這次Buffer的RGB陣列
byte[] dibArray = ShiftPixels(ref imageMemXfer, imageInfo.BitsPerPixel / 8);
BitmapRenderer.TransferPixels(bitmap, imageInfo, imageMemXfer);
pixels_written += (imageMemXfer.BytesWritten * 8) / imageInfo.BitsPerPixel;
double percent_complete = (double)pixels_written / (double)total_pixels;
if (result == TwainResult.XferDone)
{
percent_complete = 1.0;
// 算出空白區域的高度，裁切尾端部分
int blankHeight = GetCropHeight(bitmap);
if (blankHeight > 0 && blankHeight < imageInfo.ImageLength)
{
bitmap = cropImage(bitmap, blankHeight);
}
}
// fire the transfer event
TransferImageEventArgs args = new TransferImageEventArgs(bitmap, result != TwainResult.XferDone, (float)percent_complete);
TransferImage(this, args);
if (!args.ContinueScanning)
{
result = TwainResult.XferDone;
}
}
recievedBlockCount++;
} while (result == TwainResult.Success);
}
finally
{
if (imageMemXfer.Memory.TheMem != IntPtr.Zero)
{
Kernel32Native.GlobalFree(imageMemXfer.Memory.TheMem);
imageMemXfer.Memory.TheMem = IntPtr.Zero;
}
}
// End pending transfers
result = Twain32Native.DsPendingTransfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Control,
DataArgumentType.PendingXfers,
Message.EndXfer,
pendingTransfer);
if (result != TwainResult.Success)
{
DataSource.Close();
break;
}
}while (pendingTransfer.Count != 0);
}
finally
{
// Reset any pending transfers
result = Twain32Native.DsPendingTransfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Control,
DataArgumentType.PendingXfers,
Message.Reset,
pendingTransfer);
Logger.WriteLog(LOG_LEVEL.LL_NORMAL_LOG, "TransferPicturesIncremental...done.");
}
}
