我在Draggable
上有一个DragTarget
作为Stack
的一部分。里面是另一个带有Stack
的Draggables
,再次位于DragTargets
上,依此类推...(Stack
相对于Stack
高于Stack
等)。Draggable
是带有Positioned
的Listener
,告诉您放置位置。homeView.dart
body: Stack(children: [
DraggableWidget(parentKey, Offset(0, 0)),
]),
draggableWidget.dart
class DraggableWidget extends StatefulWidget {
final Key itemKey;
final Offset itemPosition;
DraggableWidget(this.itemKey, this.itemPosition);
@override
_DraggableWidgetState createState() => _DraggableWidgetState();
}
class _DraggableWidgetState extends State<DraggableWidget> {
Offset tempDelta = Offset(0, 0);
Window<List<Key>> item;
List<DraggableWidget> childList = [];
Map<Key, Window<List>> structureMap;
initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
structureMap = Provider.of<Data>(context).structureMap;
if (structureMap[widget.itemKey] != null) {
structureMap[widget.itemKey].childKeys.forEach(
(k) => childList.add(
DraggableWidget(k, item.position),
),
);
} else {
structureMap[widget.itemKey] = Window<List<Key>>(
title: 'App',
key: widget.itemKey,
size: Size(MediaQuery.of(context).size.width,
MediaQuery.of(context).size.height),
position: Offset(0, 0),
color: Colors.blue,
childKeys: []);
}
item = Provider.of<Data>(context).structureMap[widget.itemKey];
return Positioned(
top: item.position.dx,
left: item.position.dy,
child: DragTarget(
builder:
(buildContext, List<Window<List<Key>>> candidateData, rejectData) {
return Listener(
onPointerDown: (PointerDownEvent event) {},
onPointerUp: (PointerUpEvent event) {
setState(() {
item.position = Offset(item.position.dx + tempDelta.dx,
item.position.dy + tempDelta.dy);
tempDelta = Offset(0, 0);
});
},
onPointerMove: (PointerMoveEvent event) {
tempDelta = Offset((event.delta.dy + tempDelta.dx),
(event.delta.dx + tempDelta.dy));
},
child: Draggable(
childWhenDragging: Container(),
feedback: Container(
color: item.color,
height: item.size.height,
width: item.size.width,
),
child: Column(children: [
Text(item.title),
Container(
color: item.color,
height: item.size.height,
width: item.size.width,
child: ItemStackBuilder(widget.itemKey, item.position),
),
]),
data: item),
);
},
),
);
}
}
itemStackBuilder.dart
class ItemStackBuilder extends StatelessWidget {
final Key itemKey;
final Offset itemPosition;
ItemStackBuilder(this.itemKey, this.itemPosition);
@override
Widget build(BuildContext context) {
Map<Key, Window<List<Key>>> structureMap =
Provider.of<Data>(context).structureMap;
if (structureMap[itemKey] == null) {
structureMap[itemKey] = Window(size: Size(20, 20), childKeys: []);
}
return Stack(overflow: Overflow.visible, children: [
...stackItems(context),
Container(
height: structureMap[itemKey].size.height,
width: structureMap[itemKey].size.width,
color: Colors.transparent),
]);
}
List<Widget> stackItems(BuildContext context) {
List<Key> childKeyList =
Provider.of<Data>(context).structureMap[itemKey].childKeys;
var stackItemDraggable;
List<Widget> stackItemsList = [];
if (childKeyList == null || childKeyList.length < 1) {
stackItemsList = [Container()];
} else {
for (int i = 0; i < childKeyList.length; i++) {
stackItemDraggable = DraggableWidget(childKeyList[i], itemPosition);
stackItemsList.add(stackItemDraggable);
}
}
return stackItemsList;
}
}
[当我想将Draggable
项目移到顶部时,底层的Stack
移动。
我用Listener
小部件进行了尝试,并且能够检测到RenderBoxes
内部的所有Stack
。
但是如何选择特定的Draggable
和/或禁用所有其他层?忘记Draggables
并用Positioned
和GestureDetector
完成所有操作,是个更好的主意吗?
好吧,这是我的错误而不是框架的错误:在itemStackBuilder.dart上,我使用了额外的Container
来调整Stack
的大小。我无法识别,因为颜色是透明的:
Container(
height: structureMap[itemKey].size.height,
width: structureMap[itemKey].size.width,
color: Colors.transparent),
]);
}
删除此部分后,目前一切正常。