Flutter集合选择器插件collection_picker的使用
Flutter集合选择器插件collection_picker的使用
Overview
collection_picker 是一个包含高度自定义的选择列表视图和网格视图的Flutter插件，支持单选、多选和单选按钮类型。它会自动渲染选中的项，并且您可以轻松地自定义选中的项视图。
ListViewPicker
GridViewPicker
Getting Started
添加依赖
在您的 pubspec.yaml 文件中添加 collection_picker 依赖：
dependencies:
collection_picker: "^version"
导入插件
在您的 Dart 代码中导入 collection_picker：
import 'package:collection_picker/collection_picker.dart';
Usage
我们使用示例数据和模型数据来帮助您更好地理解如何使用 collection_picker。
示例模型数据
class CityModel {
String province;
String city;
CityModel(this.province, this.city);
}
示例数据列表
List<CityModel> dataCity = [
CityModel('Jakarta', 'Menteng'),
CityModel('Jakarta', 'Tebet'),
CityModel('Jakarta', 'Gambir'),
CityModel('Lampung', 'Bandar Lampung'),
CityModel('Lampung', 'Pringsewu'),
CityModel('Bandung', 'Setrasari'),
CityModel('Bandung', 'Gedebage'),
CityModel('Bandung', 'Cihanjuang'),
CityModel('Yogyakarta', 'Bantul'),
CityModel('Yogyakarta', 'Sleman'),
];
ListViewPicker
ListViewPicker<CityModel>(
type: PickerType.single,
shrinkWrap: true,
physics: const NeverScrollableScrollPhysics(),
separator: const Divider(thickness: 1, height: 16),
initialValue: dataCity.first,
data: dataCity,
itemBuilder: (PickerWrapper<CityModel> item) {
return SizedBox(
height: 20,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text('${item.data?.city}'),
(item.isSelected)
? const Icon(Icons.check)
: const SizedBox.shrink()
],
),
);
},
onChanged: (context, index, selectedItem, selectedListItem) {
// 当类型为单选或单选按钮时，应使用此方法
debugPrint('Selected item = ${selectedItem.city}');
/// 当类型为多选时，应使用此方法
debugPrint('All selected item = ${selectedListItem.map((e) => e?.city)}');
},
)
GridViewPicker
实际上与 ListViewPicker 相同，但以网格形式显示。
GridViewPicker(
type: PickerType.multiple,
shrinkWrap: true,
initialValue: dataCity.first,
data: dataCity,
gridDelegate: SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 200,
mainAxisExtent: 50,
crossAxisSpacing: 8,
),
itemBuilder: (PickerWrapper<CityModel> item) {
return Container(
padding: const EdgeInsets.all(8),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(12),
border: Border.all(color: Colors.grey.shade300),
),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text('${item.data?.city}'),
(item.isSelected)
? const Icon(Icons.check)
: const SizedBox.shrink()
],
),
);
},
onChanged: (context, index, selectedItem, selectedListItem) {
// 当类型为单选或单选按钮时，应使用此方法
debugPrint('Selected item = ${selectedItem?.city}');
/// 当类型为多选时，应使用此方法
debugPrint('All selected item = ${selectedListItem.map((e) => e?.city)}');
},
)
示例代码
以下是一个完整的示例代码，展示了如何在 Flutter 应用中使用 collection_picker 插件：
import 'package:collection_picker/collection_picker.dart';
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return const MaterialApp(
home: CollectionPickerExample(),
);
}
}
class CollectionPickerExample extends StatelessWidget {
const CollectionPickerExample({super.key});
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Collection Picker Example'),
),
body: SingleChildScrollView(
child: Column(
children: [
ListViewPicker<CityModel>(
type: PickerType.single,
shrinkWrap: true,
physics: const NeverScrollableScrollPhysics(),
separator: (BuildContext context, int index) =>
const Divider(thickness: 1, height: 16),
initialValue: dataCity.first,
data: dataCity,
unavailableDataIndex: [3, 5],
itemBuilder: (BuildContext context, int index,
PickerWrapper<CityModel> item) {
return SizedBox(
height: 20,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(item.data.city),
(!item.isAvailable)
? const Text('Unavailable')
: (item.isSelected)
? const Icon(Icons.check)
: const SizedBox.shrink()
],
),
);
},
onChanged: (context, index, selectedItem, selectedListItem) {
// 当类型为单选或单选按钮时，应使用此方法
debugPrint('Selected item = $selectedItem');
/// 当类型为多选时，应使用此方法
debugPrint('All selected item = $selectedListItem');
},
),
GridViewPicker(
type: PickerType.multiple,
shrinkWrap: true,
initialValue: dataCity.first,
data: dataCity,
gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 200,
mainAxisExtent: 50,
crossAxisSpacing: 8,
),
itemBuilder: (BuildContext context, int index,
PickerWrapper<CityModel> item) {
return Container(
padding: const EdgeInsets.all(8),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(12),
border: Border.all(color: Colors.grey.shade300),
),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(item.data.city),
if (item.isSelected) const Icon(Icons.check),
],
),
);
},
onChanged: (context, index, selectedItem, selectedListItem) {
// 当类型为单选或单选按钮时，应使用此方法
debugPrint('Selected item = ${selectedItem?.city}');
/// 当类型为多选时，应使用此方法
debugPrint(
'All selected item = ${selectedListItem.map((e) => e.city)}');
},
),
],
),
),
);
}
}
class CityModel {
String province;
String city;
CityModel(this.province, this.city);
}
List<CityModel> dataCity = [
CityModel('Jakarta', 'Menteng'),
CityModel('Jakarta', 'Tebet'),
CityModel('Jakarta', 'Gambir'),
CityModel('Lampung', 'Bandar Lampung'),
CityModel('Lampung', 'Pringsewu'),
CityModel('Bandung', 'Setrasari'),
CityModel('Bandung', 'Gedebage'),
CityModel('Bandung', 'Cihanjuang'),
CityModel('Yogyakarta', 'Bantul'),
CityModel('Yogyakarta', 'Sleman'),
];
Additional Information
感谢使用 collection_picker 插件。希望这个插件能对您有所帮助。祝您编码愉快！
更多关于Flutter集合选择器插件collection_picker的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
1 回复
更多关于Flutter集合选择器插件collection_picker的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
当然，下面是一个关于如何在Flutter中使用collection_picker插件的示例代码。这个插件允许你以优雅的方式在集合中进行选择，通常用于选择单个或多个项目。
首先，你需要在你的pubspec.yaml文件中添加collection_picker依赖：
dependencies:
flutter:
sdk: flutter
collection_picker: ^x.y.z # 替换为最新版本号
然后运行flutter pub get来安装依赖。
接下来是一个简单的例子，展示如何使用collection_picker来选择单个项目：
import 'package:flutter/material.dart';
import 'package:collection_picker/collection_picker.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String? selectedItem;
final List<String> items = ['Item 1', 'Item 2', 'Item 3', 'Item 4'];
void _onItemSelected(String item) {
setState(() {
selectedItem = item;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Collection Picker Example'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
selectedItem ?? 'No item selected',
style: TextStyle(fontSize: 24),
),
SizedBox(height: 20),
ElevatedButton(
onPressed: () {
showPicker(
context: context,
collection: items,
initialSelected: selectedItem,
onSelected: _onItemSelected,
builder: (context, options) {
return CollectionPicker(
options: options,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: Text(items[index]),
);
},
);
},
);
},
child: Text('Select Item'),
),
],
),
),
);
}
}
在这个例子中，我们创建了一个包含四个字符串项目的列表。当用户点击按钮时，会显示一个选择器，允许用户从列表中选择一个项目。选择后，将更新UI以显示所选项目。
如果你需要选择多个项目，可以使用MultiSelectionPicker。以下是修改后的代码示例：
import 'package:flutter/material.dart';
import 'package:collection_picker/collection_picker.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Set<String>? selectedItems;
final List<String> items = ['Item 1', 'Item 2', 'Item 3', 'Item 4'];
void _onItemsSelected(Set<String> items) {
setState(() {
selectedItems = items;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Multi Collection Picker Example'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
selectedItems?.join(', ') ?? 'No items selected',
style: TextStyle(fontSize: 24),
),
SizedBox(height: 20),
ElevatedButton(
onPressed: () {
showPicker(
context: context,
collection: items,
initialSelected: selectedItems?.toList() ?? [],
allowMultiSelect: true,
onSelected: _onItemsSelected,
builder: (context, options) {
return MultiSelectionPicker(
options: options,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: Text(items[index]),
);
},
);
},
);
},
child: Text('Select Items'),
),
],
),
),
);
}
}
在这个多选例子中，我们使用MultiSelectionPicker来允许用户选择多个项目，并在选择后更新UI以显示所选项目的列表。
这两个例子展示了如何在Flutter中使用collection_picker插件进行单个和多个项目的选择。希望这些代码对你有帮助！
