flutter - 可重新排序 ListView : Exception: BoxConstraints forces an infinite height

Question

TL;DR - 如何实现 shrinkWrap = true在ReorderableListView ?

我试图创建一个 ReoderableListView与 Column<-Container作为 parent ，发生了这个错误。

I/flutter (32618): The following assertion was thrown during performLayout():
I/flutter (32618): BoxConstraints forces an infinite height.


I/flutter (32618): The following RenderObject was being processed when the exception was fired: RenderStack#23840 relayoutBoundary=up17 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter (32618):   creator: Stack ← _Theatre ← Overlay-[GlobalKey#dc153 ReorderableListView overlay key] ←
I/flutter (32618):     ReorderableListView ← StreamBuilder<QuerySnapshot> ← Column ← Padding ← Padding ← Container ←
I/flutter (32618):     BoardCard ← Column ← _SingleChildViewport ← ⋯
I/flutter (32618):   parentData: not positioned; offset=Offset(0.0, 0.0) (can use size)
I/flutter (32618):   constraints: BoxConstraints(0.0<=w<=328.0, 0.0<=h<=Infinity)
I/flutter (32618):   size: MISSING
I/flutter (32618):   alignment: AlignmentDirectional.topStart
I/flutter (32618):   textDirection: ltr
I/flutter (32618):   fit: expand
I/flutter (32618):   overflow: clip
I/flutter (32618): This This RenderObject had the following child:
I/flutter (32618):     child 1: _RenderLayoutBuilder#55d3d NEEDS-LAYOUT NEEDS-PAINT

如果它是 ListView，这将很容易修复通过使用 shrinkWrap = true但是ReorderableListView没有这个属性。

这是代码

@override
  Widget build(BuildContext context) {
    final _listTitleStyle =
        TextStyle(fontSize: 20, fontWeight: FontWeight.w500);
    final _listSubTitleStyle = TextStyle(
      fontSize: 14,
      fontWeight: FontWeight.w400,
      color: Color(0xff7D7373),
    );
    return Container(
      padding: EdgeInsets.all(8),
      margin: EdgeInsets.all(8),
      child: Column(
        children: <Widget>[
          Container(
            child: Row(
              children: <Widget>[
                Expanded(
                  child: Row(
                    textBaseline: TextBaseline.alphabetic,
                    crossAxisAlignment: CrossAxisAlignment.baseline,
                    children: <Widget>[
                      Text(
                        widget.cardTitle,
                        style: _listTitleStyle,
                      ),
                      SizedBox(
                        width: 2,
                      ),
                      Text(
                        widget.cardSubTitle,
                        style: _listSubTitleStyle,
                      ),
                    ],
                  ),
                ),
                Icon(Icons.keyboard_arrow_down),
              ],
            ),
          ),
          SizedBox(
            height: 8,
          ),
          StreamBuilder<QuerySnapshot>(
              stream: widget.query,
              builder: (context, snapshot) {
                if (!snapshot.hasData) return LinearProgressIndicator();
                return _buildList(context, snapshot.data.documents);
              }),
        ],
      ),
    );
  }

  Widget _buildList(BuildContext context, List<DocumentSnapshot> snapshot) {
    snapshot.forEach((snap) {
      print("debug 1 ${snap.data}");
      print(TodoItem.fromSnapshot(snap, snap.reference).toString());
    });
    return ReorderableListView(
      onReorder: (oldIndex, newIndex){},
      children: snapshot
          .map((data) => TodoTile(TodoItem.fromSnapshot(data, data.reference), key: UniqueKey(),))
          .toList(),
    );
  }

Answer 1

我已通过将 ReorderableListView 替换为包 flutter_reorderable_list 来解决此问题, 它接受一个 child (Widget) 不像 ReorderableListView 接受 child (List)

它的实现有点复杂。你可以看看example了解如何正确实现它。