As there currently isn't a way to determine when a page changes when scrolling, I hook into the PropertyChanged event of the RadPdfViewer and check the VisiblePagesStartIndex property, however when scrolling to the last page of the PDF the VisiblePagesStartIndex does not match, for example, I have a 10 page PDF document and when I scroll all the way to the bottom, the last VisiblePagesStartIndex property change is 8, when it should be 9. If I then invoke the NavigateToNextPageCommand then the VisiblePagesStartIndex property changes to the expected value of 9, although I am already at the bottom of the document.
In effect I need to know when I reach the end of the PDF so that I can update my own UI buttons to reflect the current position in the document, for example, disabling the down button when I can no longer navigate to a next page. I can achieve this when using the NavigateToNextPageCommand and NavigateToPreviousPageCommand method of document navigation but not when scrolling.
I have tried a work around where if the VisiblePagesStartIndex is 8 then invoke the NavigateToNextPageCommand but this doesn't work when scrolling back up the document.