Flutter - ListView.builder 呈现小部件但不可滚动

Question

I have my ListView.builder inside Expanded widget which render widgets correctly on the screen but I cannot scroll the widgets rendered by it.

Widget build(BuildContext context) {
    return Container(
      child: FutureBuilder(
        future: getPostsForUid(),
        builder: (_, snap) {
          return Expanded(
            child: ListView.builder(
              physics: AlwaysScrollableScrollPhysics(),
              shrinkWrap: true,
              itemCount: snap.data.length,
              itemBuilder: (_, index) {
                if (snap.data[index]['post_type'] == 'real_estate') {
                  return realEstate(snap, index);
                }
                else if (snap.data[index]['post_type'] == 'video_sharing') {
                  return videoSharing(snap, index);
                }
                else {
                  return Text('');
                }

              },
            ),
          );
        },
      ),
    );
  }

This renders widgets but there is no overflow but its not Scrollable. Using AlwaysScrollableScrollPhysics , NeverScrollableScrollPhysics , ScrollPhysics in physics doesn't work either. Also tring shrinkWrap as false returns no widgets whatsoever.

Answer 1

The list view thinks it's bigger, because your container has no fixed height. Try setting the height of the container to MediaQuery.of(context).size.height and the list view will know its bounds.

Answer 2

it will not scroll while it's shrinkWrap is true.

try this:

ListView.builder(
              physics: AlwaysScrollableScrollPhysics(),
              itemExtent: 'sizeOfeachElement (ex:100)'

and remove Expanded