¿Cómo detectar la posición de desplazamiento de la vista de lista en Flutter?

How to detect scroll position of listview in flutter?

I used NotificationListener that is a widget that listens for notifications bubbling up the tree. Then use ScrollEndNotification, which indicates that scrolling has stopped. For scroll position I used _scrollController that type is ScrollController.

You can use a ListView.builder to create a scrolling list with unlimited items. Your itemBuilder will be called as needed when new cells are revealed. If you want to be notified about scroll events so you can load more data off the network, you can pass a controller argument and use addListener to attach a listener to the ScrollController.

Sometimes it becomes difficult for the user to decide whether the screen is scrollable or not because a user is not able to see the scrollbar on the screen. Flutter ListView widget does not provide the inbuilt facility to show the scrollbar.

How can we know if a Widget, part of a ListView (or GridView), is actually visible on the screen and how to detect whether it becomes visible when the user scrolls? Here is the code of a possible solution. I will give the explanations after… This solution is based on:

Once we have our widget, the first step is to declare a ScrollController variable. We instantiate it within our initState method, in the following way: Then we assign this _controller to our ListView. With this we have our ListView connected with our ScrollController, we just have to listen to the events to determine what we want.

In the majority of the apps we do, we have at least one Scrollable Widget. In some cases we want to extend the use of our elements within a scroll, for example: 1- When we want to know if we reach at the beginning or end of a list.

The trick is to only apply the ScrollView when you need to, and otherwise to let the content expand.