Flutter - ListView.builder 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: NeverScrollableScrollPhysics(),
              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('');
                }
              },
            ),
          );
        },
      ),
    );
  }

Answer 1

Try using ScrollPhysics() class, physics: ScrollPhysics() , here is the link for reference for the same.

Answer 2

You should set your physics to AlwaysScrollableScrollPhysics() . The docs state the following:

Scroll physics that always lets the user scroll. This overrides the default behavior which is to disable scrolling when there is no content to scroll. It does not override the handling of overscrolling. On Android, overscrolls will be clamped by default and result in an overscroll glow. On iOS, overscrolls will load a spring that will return the scroll view to its normal range when released.

Here is an image of "overscroll glow" for you to understand what that means.

Consider using shrinkWrap: false to expand your contents in case they are bounded.

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('No data available.');
                }
              },
            ),
          );
        },
      ),
    );
  }

See the docs:

• https://api.flutter.dev/flutter/widgets/AlwaysScrollableScrollPhysics-class.html

Answer 3

Add Physics:AlwaysScrollable() in your Listview .

Answer 4

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: NeverScrollableScrollPhysics(),
              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('');
                }
              },
            ),
          );
        },
      ),
    );
  }