使 ListView 滚动到一个偏移量

Question

I am trying to show the top element on the screen in listView to show completely or to scroll up.

child: NotificationListener<ScrollEndNotification>(
          onNotification: (_) {
            double h = 120;
            double remaining = controller.position.pixels % h;
            int offset = 0;
            offset = (remaining > 60)
                ? ((controller.position.pixels ~/ h) + 1) * 120
                : ((controller.position.pixels ~/ h)) * 120;
            if (offset > 0) 
                controller.animateTo(offset.toDouble(),
                           duration: Duration(milliseconds: 500), curve: Curves.easeInOut);
            return true;
          },
          child: ScrollConfiguration(
            behavior: NoEffectScrollBehaviour(),
            child: ListView.builder(
                padding: EdgeInsets.zero,
                controller: controller,
                physics: BouncingScrollPhysics(),
                itemBuilder: (c, i){.......}

But the controller is not scrolling to the specified position. How can I make it the listView Elenent to either show or animate to offset?

Edit:

I am making the transition on scroll end event. The problem is I am not able to do it in NotificationListner.

Answer 1

First of all you don't need NotificationListener. You can simply below method.

if you want scroll first element or scroll to top you can use

controller.animateTo(0,duration: Duration(milliseconds: 500), curve: Curves.easeInOut);

if you want to go specific item you can use

final listItemHeight = 50;
final itemIndex = 3;
controller.animateTo(listItemHeight * itemIndex,duration: Duration(milliseconds: 500), curve: Curves.easeInOut);