建立在Pierre的答案上,我最终实现了一个解决方法,它允许我使用
DraggableScrollableActuator
来折叠和展开
DraggableScrollableSheet
。
您可以使用
setState
方法更改
initialChildSize
的值,然后使用
DraggableScrollableActuator.reset
方法来展开或折叠表格。
void toggleDraggableScrollableSheet() {
if (draggableSheetContext != null) {
setState(() {
initialExtent = isExpanded ? minExtent : maxExtent;
});
DraggableScrollableActuator.reset(draggableSheetContext);
}
}
要使这个工作成立的重要事情是为小部件折叠和展开时提供不同的Key
。这将导致两个 _DraggableScrollableSheetState
实例 - 一个可以重置为折叠状态,另一个可以重置为展开状态。
DraggableScrollableActuator(
child: DraggableScrollableSheet(
key: Key(initialExtent.toString()),
minChildSize: minExtent,
maxChildSize: maxExtent,
initialChildSize: initialExtent,
builder: draggableScrollableSheetBuilder,
),
)
编辑:
工作示例:
import 'package:flutter/material.dart';
void main() async {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
State<StatefulWidget> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
static const List<Color> colors = [
Colors.red,
Colors.green,
Colors.blue,
];
static const double minExtent = 0.2;
static const double maxExtent = 0.6;
bool isExpanded = false;
double initialExtent = minExtent;
BuildContext draggableSheetContext;
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: _buildBody(),
),
);
}
Widget _buildBody() {
return InkWell(
onTap: _toggleDraggableScrollableSheet,
child: DraggableScrollableActuator(
child: DraggableScrollableSheet(
key: Key(initialExtent.toString()),
minChildSize: minExtent,
maxChildSize: maxExtent,
initialChildSize: initialExtent,
builder: _draggableScrollableSheetBuilder,
),
),
);
}
void _toggleDraggableScrollableSheet() {
if (draggableSheetContext != null) {
setState(() {
initialExtent = isExpanded ? minExtent : maxExtent;
isExpanded = !isExpanded;
});
DraggableScrollableActuator.reset(draggableSheetContext);
}
}
Widget _draggableScrollableSheetBuilder(
BuildContext context,
ScrollController scrollController,
) {
draggableSheetContext = context;
return SingleChildScrollView(
controller: scrollController,
child: Column(
children: colors
.map((color) => Container(
height: 200,
width: double.infinity,
color: color,
))
.toList(),
),
);
}
}
animateTo
方法到DraggableScrollableActuator
中,这将解决该问题: https://github.com/flutter/flutter/issues/45009 - gtrochimiuk