Last Updated: 25 Oct 2019 11:02 by ADMIN
Created on: 01 May 2018 10:57
Category: ListView
Type: Feature Request
ListView: Introduce API for providing scroll info when the control's scrollview position is changed

Posted on: 25 Oct 2019 11:02


Thank you for describing the scenario at hand in details.  I agree that having the information about the scroll position and when it is changed would be useful in a number of scenarios.

At the moment this functionality is not in our immediate plans, still we are keeping an eye on the item and we're tracking the demand.  Please follow it in order to get notified on any status update.

Progress Telerik

Posted on: 25 Oct 2019 10:21

For example, I made a floating searchbar with transparent frame, and a RadListView with HeaderTemplate that can be longer than one or two screen height of the device. At the end of the page is a scrollable product listing that will kept on load more products on demand.

I would like to detect the scroll position of the ListView, so if the scroll Y is more than 10px vertically, I can change the color of the toolbar to my desired color.

Using ItemAppearing event won't be able to achieve as user will need to scroll until more than 2 screen height of device only will trigger the first item.

ScrollView provide Scrolled event, but I can't use the ScrollView wrapping the content and the RadListView as it will mess up the scroll of the RadListView.

Placing ScrollView wrapping the content, next to a RadListView is also not an option as it will be come 2 scroll content at seperated section.

That's why the only choice is to place content inside the HeaderTemplate so we can achieve a fully scrollable page, and infinite product listing at the bottom.

Enable Scrolled event and info allow developer to do all sort's of things like animation, or showing info on a certain scrolling position.

For example, you can check this out. Something you can do with the "Scrolled" event on CarouselView. It's a different control, but you can see similar thing can be done with the ListView with Scrolled event as well.