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 ThumbnailViewer Sample for iGrid ActiveX
 
 Control Version: 3.0
 Environment: Visual Basic 6

 Copyright (c) 10Tec Company. All rights reserved.
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Description
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iGrid's custom-draw cells allow you to display images not only from imagelist controls - you can draw images or their thumbnails from files stored on your hard drive too. The thumbnail viewer implemented in this demo is based on iGrid and demonstrates how you can do it.
  
Developer's Tips
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This demo uses the IExtractImage operating system interface to get thumbnail images for files from the specified folder. In Windows 2000 and above, the system by default will provide thumbnail viewers for pictures (BMP, GIF, JPEG, PNG), video files (AVI, MPG etc), Office documents (DOC, PPT, XLS, WMF), Web pages (HTML, MHT) and e-mail messages (EML). Note that Office documents can be previewed only if they've been saved with an embedded preview picture - you need to check the box in the Properties dialog to enable this.

As MSDN states, IExtractImage is implemented in shell32.dll version 4.70 or later. The v4.7 is redistributed with Microsoft Internet Explorer 3.x so this code should work properly on any version of Windows (perhaps, Windows 95 and 98 do not have so many built-in thumbnail generators as Win2000 or  higher).

The code also uses the pcMemDC class by Steve McMahon (vbAccelerator.com) to store thumbnail images in the memory and then quickly draw them in iGrid. More info about using this interface and the pcMemDC class you can find on his Web-site at
http://www.vbaccelerator.com/home/VB/Code/Libraries/Shell_Projects/Thumbnail_Extraction/article.asp

Our implementation simply creates instances of the pcMemDC class filled with thumbnail images of files in the specified folder, and stores these objects in row tags. These objects are used later in the iGrid1_CustomDrawCell event sub to draw the thumbnails in iGrid cells.

Notice also that you can change the width of the column with thumbnails and then double click its divider to automatically fit the width of the column (see the iGrid1_CustomDrawCellGetSize event sub).
  
Requirements
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As we mentioned above, the code should work properly on any version of Windows, but if the IExtractImage interface does not work in your version of Windows, please, let us know by sending a letter to our support service.