Scroll Bar Raster Image List Event

Hello, I am using Leadtools 14.5 for .Net 2
I have a 5000 Pages TIF document I need to load in a rasterviewer and rasterimagelist
I load the first page to the viewer and I had created all the 5000 items in the rasterimagelist without a thumbnail,
after that I just update the thumbnails image for the first 10 items
I want to create the thumbnail image on demand, just after the user release the mouse when finish scrolling.
I am trying to find an event where to implement this
could you please help me with that?
Thanks a lot.

Hello,

We don't seem to have online links for v14.5's RasterImageList, however when looking over the v15 documentation page it appears there is a Scroll event:
https://www.leadtools.com/help/leadtools/v15/dh/wi/leadtools.winforms~leadtools.winforms.rasterimagelist~scroll_ev.html

From there, you can use the TopIndex property to determine the first visible item:
https://www.leadtools.com/help/leadtools/v15/dh/wi/leadtools.winforms~leadtools.winforms.rasterimagelist~topindex.html

The VisibleColumns and VisibleRows properties can be used for determining which other items are visible:

• VisibleColumns: https://www.leadtools.com/help/leadtools/v15/dh/wi/leadtools.winforms~leadtools.winforms.rasterimagelist~visiblecolumns.html
  
• VisibleRows: https://www.leadtools.com/help/leadtools/v15/dh/wi/leadtools.winforms~leadtools.winforms.rasterimagelist~visiblerows.html

It may also be beneficial to keep track of which items have actual content, so you can dispose off-screen items and keep the memory usage down.

If v14.5 does not have this event or the properties mentioned, please let me know and I will attempt to create a sample project demonstrating the correct method for doing this.

Thanks,