Files
2022-03-26 16:41:34 +08:00

68 lines
1.9 KiB
Dart

import 'package:flutter/material.dart';
/// create by 张风捷特烈 on 2020-03-16
/// contact me by email 1981462002@qq.com
/// 说明:
// {
// "widgetId": 55,
// "name": 'DropdownButton基本用法',
// "priority": 1,
// "subtitle":
// "【value】 : 当前值 【T】\n"
// "【items】 : 下拉选框 【List<DropdownMenuItem<T>>】\n"
// "【icon】 : 图标 【Widget】\n"
// "【elevation】 : 影深 【double】\n"
// "【onChanged】 : 选择条目事件 【Function(T)】\n"
// "【backgroundColor】 : 背景色 【Color】",
// }
class CustomDropDownButton extends StatefulWidget {
const CustomDropDownButton({Key? key}) : super(key: key);
@override
_CustomDropDownButtonState createState() => _CustomDropDownButtonState();
}
class _CustomDropDownButtonState extends State<CustomDropDownButton> {
Color _color = Colors.red;
final List<Color> _colors = const [
Colors.red,
Colors.yellow,
Colors.blue,
Colors.green
];
final List<String> _info = const ["红色", "黄色", "蓝色", "绿色"];
@override
Widget build(BuildContext context) {
return Wrap(
children: <Widget>[
Container(
margin: const EdgeInsets.symmetric(horizontal: 20),
width: 50,
height: 50,
color: _color,
),
DropdownButton<Color>(
value: _color,
elevation: 1,
icon: Icon(
Icons.expand_more,
size: 20,
color: _color,
),
items: _buildItems(),
onChanged: (v) => setState(() => _color = v??Colors.blue)),
],
);
}
List<DropdownMenuItem<Color>> _buildItems() => _colors
.map((e) => DropdownMenuItem<Color>(
value: e,
child: Text(
_info[_colors.indexOf(e)],
style: TextStyle(color: e),
)))
.toList();
}