flutter - Flutter 可拖动的可滚动工作表
问题描述
有谁知道为什么我的可拖动滚动表不起作用或为什么我看不到它?我以另一种方式尝试了它,但我没有使用 SafeArea-Widget,
import 'package:flutter/material.dart';
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: PreferredSize(
preferredSize: Size.fromHeight(100.0),
child: AppBar(
//AppBar
),
body: SafeArea(
child: ListView(
children: <Widget>[
Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
dateday,
style: TextStyle(
color: Color(0xff2C8E5D),
fontSize: 150,
),
),
),
SizedBox.expand(
child: DraggableScrollableSheet(builder:
(BuildContext context, ScrollController scrollController) {
return Container(
color: Colors.red,
child: ListView.builder(
controller: scrollController,
itemCount: 25,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text("Item $index"));
}),
);
}),
),
],
),
),
);
}
}
谢谢你的帮助!
解决方案
您可以使用LayoutBuilder
andBoxConstraints
来提供height
和使用Expanded flex
来控制DraggableScrollableSheet
的滚动区域
代码片段
SafeArea(
child: LayoutBuilder(builder: (context, constraints) {
return ConstrainedBox(
constraints: BoxConstraints(maxWidth: constraints.maxWidth),
child: Column(
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
"dateday",
...
Expanded(
flex: 3,
child: SizedBox.expand(
工作演示
完整代码
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('DraggableScrollableSheet'),
),
body: SafeArea(
child: LayoutBuilder(builder: (context, constraints) {
print(constraints.maxWidth);
print(constraints.minWidth);
return ConstrainedBox(
constraints: BoxConstraints(maxWidth: constraints.maxWidth),
child: Column(
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
"dateday",
style: TextStyle(
color: Color(0xff2C8E5D),
fontSize: 150,
),
),
),
),
Expanded(
flex: 3,
child: SizedBox.expand(
child: DraggableScrollableSheet(builder:
(BuildContext context,
ScrollController scrollController) {
return Container(
color: Colors.red,
child: ListView.builder(
controller: scrollController,
itemCount: 25,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text("Item $index"));
}),
);
}),
),
),
],
),
);
}),
));
}
}
推荐阅读
- r - 过滤中未找到对象
- java - 如何从命令行验证 Java 中有用的 ECC 算法?,在 IIB 使用之前
- mysql - 如何基于 2 个 JSON 对象列内部连接两个表?
- typescript - 构造函数接口:没有匹配构造函数的类仍然是可赋值的
- flutter - Dart:在 Flutter 应用程序中最小化对 Firebase 的访问
- css-grid - 为什么 CSS Grid-Area 结束坐标偏移?
- google-cloud-firestore - 按包含“.”的映射键查询
- wso2 - WSO 7.0 Micro Integrator 多数据服务
- asp.net-core - ASP.NET Core MVC:模型绑定和复杂类型
- php - 如何获取表单选择值以显示正在插入的表中的两件事?