Flutter拖拽网格布局插件drag_grid的使用
Flutter拖拽网格布局插件drag_grid的使用
1. 安装插件
首先，你需要在 pubspec.yaml 文件中添加 drag_grid 插件，并运行命令行安装。
dependencies:
drag_grid: ^1.0.8
然后，在命令行中执行以下命令：
flutter pub get
2. 示例代码
下面是一个完整的示例代码，展示了如何使用 drag_grid 插件创建一个支持拖拽功能的网格布局。
import 'package:flutter/material.dart';
import 'package:drag_grid/drag_grid.dart';
import 'package:drag_grid/drag_grid_controller.dart';
import 'package:flutter_vibrate/flutter_vibrate.dart';
void main() {
runApp(const MyApp());
}
class TestData {
TestData({
this.value = '0',
this.color,
});
String value;
Color? color;
}
class MyApp extends StatefulWidget {
const MyApp({super.key});
[@override](/user/override)
State<MyApp> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
GridController<TestData> gridController = GridController();
List<TestData> itemList = [];
int lastIndex = 0;
[@override](/user/override)
void initState() {
super.initState();
itemList = List.generate(16, (i) => TestData(value: '$i'));
lastIndex = 16;
}
[@override](/user/override)
Widget build(BuildContext context) {
const sliverGridDelegate = SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 4,
mainAxisSpacing: 10,
crossAxisSpacing: 10,
childAspectRatio: 1,
);
return Stack(
fit: StackFit.expand,
children: [
ListView(
shrinkWrap: false,
padding: const EdgeInsets.only(
top: 20.0,
left: 20.0,
right: 19.0,
bottom: 24.0,
),
children: [
SizedBox(
child: DragGrid<TestData>(
itemList: itemList,
gridController: gridController,
sliverGridDelegate: sliverGridDelegate,
itemBuilder: (context, item, index) {
return Container(
alignment: Alignment.center,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Container(
width: 64.0,
height: 64.0,
decoration: ShapeDecoration(
gradient: const RadialGradient(
center: Alignment(0.0, 0.0),
radius: 1.5,
colors: [
Color(0xffe0e0e0),
Color(0xfff0f0f0),
],
),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(
5.0,
),
),
),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
item.value,
style: const TextStyle(
color: Color(0xff404244),
fontWeight: FontWeight.bold,
fontSize: 16.0,
height: 1,
),
),
],
),
),
],
),
);
},
itemListChanger: (list) {
setState(() {
itemList = list;
});
},
onDragStarted: () async {
if (await Vibrate.canVibrate) {
Vibrate.feedback(FeedbackType.heavy);
}
},
),
),
],
),
Positioned(
left: 0,
bottom: 48,
child: Container(
width: MediaQuery.of(context).size.width,
padding: const EdgeInsets.symmetric(horizontal: 48.0),
child: Column(
children: [
GestureDetector(
behavior: HitTestBehavior.opaque,
child: Container(
height: 52.0,
margin: const EdgeInsets.symmetric(vertical: 10.0),
alignment: Alignment.center,
decoration: ShapeDecoration(
gradient: const RadialGradient(
center: Alignment(0.0, 0.0),
radius: 1.8,
colors: [
Color(0xffe0e0e0),
Color(0xfff0f0f0),
],
),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(
12.0,
),
),
),
child: const Text(
'在第2个元素插入',
style: TextStyle(
fontSize: 14.0,
fontWeight: FontWeight.bold,
color: Color(0xff707377),
letterSpacing: 1.5,
height: 1,
),
),
),
onTap: () {
gridController.insert(
item: TestData(value: '${lastIndex++}'),
index: 1,
);
},
),
GestureDetector(
behavior: HitTestBehavior.opaque,
child: Container(
height: 52.0,
margin: const EdgeInsets.symmetric(vertical: 10.0),
alignment: Alignment.center,
decoration: ShapeDecoration(
gradient: const RadialGradient(
center: Alignment(0.0, 0.0),
radius: 1.8,
colors: [
Color(0xffe0e0e0),
Color(0xfff0f0f0),
],
),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(
12.0,
),
),
),
child: const Text(
'删除第2个元素',
style: TextStyle(
fontSize: 14.0,
fontWeight: FontWeight.bold,
color: Color(0xff707377),
letterSpacing: 1.5,
height: 1,
),
),
),
onTap: () {
gridController.remove(index: 1);
},
),
],
),
),
)
],
);
}
}
更多关于Flutter拖拽网格布局插件drag_grid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拖拽网格布局插件drag_grid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，以下是一个关于如何在Flutter中使用drag_grid插件来实现拖拽网格布局的示例代码。drag_grid插件允许你创建一个可以拖拽排序的网格视图。
首先，确保你已经在你的pubspec.yaml文件中添加了drag_grid依赖：
dependencies:
flutter:
sdk: flutter
drag_grid: ^x.y.z # 请替换为最新版本号
然后，运行flutter pub get来安装依赖。
接下来，你可以使用以下代码来创建一个简单的拖拽网格布局：
import 'package:flutter/material.dart';
import 'package:drag_grid/drag_grid.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Drag Grid Example',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final List<String> items = List.generate(25, (i) => "Item ${i + 1}");
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Drag Grid Example'),
),
body: Padding(
padding: const EdgeInsets.all(8.0),
child: DragGrid<String>(
data: items,
itemBuilder: (context, item, index) {
return Card(
child: Center(
child: Text(item),
),
);
},
onReorder: (oldIndex, newIndex) {
if (oldIndex < newIndex) {
newIndex -= 1;
}
final String item = items.removeAt(oldIndex);
items.insert(newIndex, item);
setState(() {});
},
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 3,
crossAxisSpacing: 4.0,
mainAxisSpacing: 4.0,
childAspectRatio: 1.0,
),
),
),
);
}
}
代码解释
-
依赖引入：
- 在
pubspec.yaml中添加drag_grid依赖。
- 在
-
主应用：
MyApp是一个无状态组件，定义了应用的主题和主页。
-
主页：
MyHomePage是一个有状态组件，包含了一个List<String>来存储网格项。- 使用
DragGrid组件来显示网格布局，并允许用户拖拽排序。
-
DragGrid组件：data：传入要显示的网格项数据。itemBuilder：定义了每个网格项的构建方式，这里使用了Card和Text。onReorder：当用户拖拽网格项后，这个回调会被触发，用于更新数据顺序。gridDelegate：定义了网格的布局，这里使用SliverGridDelegateWithFixedCrossAxisCount来创建一个固定列数的网格布局。
这段代码展示了如何使用drag_grid插件来创建一个简单的拖拽网格布局，你可以根据需要进一步自定义和扩展这个示例。
