qhd-prevention-flutter/lib/customWidget/bottom_picker.dart

84 lines
2.5 KiB
Dart

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';
/// 通用底部弹窗选择器
/// Example:
/// ```dart
/// final choice = await BottomPicker.show<String>(
/// context,
/// items: ['选项1', '选项2', '选项3'],
/// itemBuilder: (item) => Text(item, textAlign: TextAlign.center),
/// initialIndex: 1,
/// );
/// if (choice != null) {
/// // 用户点击确定并选择了 choice
/// }
/// ```
class BottomPicker {
/// 显示底部选择器弹窗
///
/// [items]: 选项列表
/// [itemBuilder]: 每个选项的展示 Widget
/// [initialIndex]: 初始选中索引
/// [itemExtent]: 列表行高
/// [height]: 弹窗总高度
static Future<T?> show<T>(
BuildContext context, {
required List<T> items,
required Widget Function(T item) itemBuilder,
int initialIndex = 0,
double itemExtent = 40.0,
double height = 250,
}) {
// 当前选中项
T selected = items[initialIndex];
return showModalBottomSheet<T>(
context: context,
backgroundColor: Colors.white,
shape: const RoundedRectangleBorder(
borderRadius: BorderRadius.vertical(top: Radius.circular(12)),
),
builder: (ctx) {
return SizedBox(
height: height,
child: Column(
children: [
// 按钮行
Padding(
padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
TextButton(
onPressed: () => Navigator.of(ctx).pop(),
child: const Text('取消'),
),
TextButton(
onPressed: () => Navigator.of(ctx).pop(selected),
child: const Text('确定'),
),
],
),
),
const Divider(height: 1),
// 滚动选择器
Expanded(
child: CupertinoPicker(
scrollController:
FixedExtentScrollController(initialItem: initialIndex),
itemExtent: 30,
onSelectedItemChanged: (index) {
selected = items[index];
},
children: items.map(itemBuilder).toList(),
),
),
],
),
);
},
);
}
}