изменять:
Made a project with lazy loading 10000 records based on your solution. The search will be carried out by the index of the line. There are a couple of questions left that, in my opinion, should not be posted in a new thread, since the CLVExpandable class has been changed.
Questions:
1. How to open an expanding list at the desired index?
2. Is it possible to apply a ListView with any number of rows so that all of them are visible in the drop-down list?