DelphiTwain how to show form setting

I'm using Delphitwain (delphitwain.sourceforge.net) to add scan functionality to my app. Everything was fine, when i click scan button on my app it will show scan mode with scanner's Properties such as Page Size, Scanning Side (canon dr-3010c) and there is a Scan button and Cancel button. If i click cancel of course all the properties back to it's value before.

How can I show this Scanner's Properties only to change properties without Scan, since i can do scan without showing properties

Twain.LoadLibrary;
Twain.LoadSourceManager;
Twain.Source[CurrentSource].Loaded := TRUE;
Twain.Source[CurrentSource].TransferMode := TTwainTransferMode(0);
Twain.Source[CurrentSource].EnableSource(True, True);
while Twain.S开发者_运维知识库ource[CurrentSource].Enabled do Application.ProcessMessages;
Twain.UnloadLibrary;

Twain.Source[CurrentSource].EnableSource(True, True);

The first True for ShowUI and the second True for Modal

I know it can be achieved 'cos i've seen another application that can show scanner's properties without scan, only OK and Cancel button, i've searched google all over but no luck, or maybe it just the limitation of the delphitwain component? Thanks, any suggestion appreciated

It has a boolean property in TTwainSource class named ShowUI. Using that property, you can control whether native UI of the scanner should be shown or not.

But take note that some scanners show their UI forcefully whether you set ShowUI to True or False.