I tested the demo you are referring to and found that it works as expected.
The Twain dialog displays the scanners progress, then when the scan is complete the progress bar on the form also show progress when the image is transferred to ImageEnMView.
This is expected because this is the code that sets the progressbar position:
procedure TfrmMain.ImageEnIO1Progress(Sender: TObject; per: Integer);
const
Show_Images_As_Acquired = True;
begin
ProgressBar1.Position := per;
if Show_Images_As_Acquired then
begin
ImageEnMView1.Update;
Application.ProcessMessages;
end;
end;
This code only executes when the image is transferred to ImageEnMView.
If you want to control the scanner without using a Twain Dialog then look at the Demos\ImageAquisition\WIAScanner demo. This demo sets the scanner settings by using ImageEnView1.IO.WIAParams. With this demo as the scan ocurrs the progress is shown by the progressbar on the main form for the application.
William Miller
Adirondack Software & Graphics
Email: w2m@frontiernet.net
EBook: http://www.imageen.com/ebook/
Apprehend: http://www.frontiernet.net/~w2m/index.html
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Bug - no onprogress event - Twain
Posted - Jan 17 2014 : 13:07:33
