I’m using a Dictionary to index a ListBox content. It takes the string in the first column as the key and the row index as the value. In order to maintain the index accurate, I need to know when the ListBox has been sorted by the user, but it seems there is no event for that. I’m currently using a boolean flag set in the ListBox.SortColumn() Event. Each time a specific string is searched in the first column is searched the flag is tested and if it’s True, the index is rebuild. It works fine, but just out of curiosity, I’d like to know if there is a way to be advised when a ListBox is sorted?