Flutter多级选择器插件flutter_multi_selector_drop_down的使用

在本示例中，我们将展示如何在Flutter应用中使用flutter_multi_selector_drop_down插件。该插件允许用户从下拉列表中选择多个选项，并且具有丰富的自定义选项。

项目依赖

首先，确保在你的pubspec.yaml文件中添加了flutter_multi_selector_drop_down依赖：

dependencies:
  flutter:
    sdk: flutter
  flutter_multi_selector_drop_down: ^版本号
  get: ^版本号

然后运行flutter pub get来获取依赖包。

创建多级选择器

我们将创建一个简单的表单，其中包含一个多级选择器组件。以下是完整的代码示例：

import 'package:flutter/material.dart';
import 'package:flutter_multi_selector_drop_down/flutter_multi_selector_drop_down.dart';
import 'package:flutter_multi_selector_drop_down/model/drop_down_decoration_model.dart';
import 'package:flutter_multi_selector_drop_down/widget/advance_drop_down.dart';
import 'package:get/get.dart';

class MyAdvancedDropdownWidget extends StatefulWidget {
  final DropDownDecorationModel? tableDecorationModel;

  const MyAdvancedDropdownWidget({
    Key? key,
    this.tableDecorationModel,
  }) : super(key: key);

  [@override](/user/override)
  State<MyAdvancedDropdownWidget> createState() => _MyAdvancedDropdownWidgetState();
}

class _MyAdvancedDropdownWidgetState extends State<MyAdvancedDropdownWidget> {
  final GlobalKey<AdvancedDropDownSelectWidgetState> dropDownKey = GlobalKey<AdvancedDropDownSelectWidgetState>();

  final RxBool isDropDownOpen = false.obs; // For tracking dropdown state

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Material(
      child: Center(
        child: SizedBox(
          width: getSize(232),
          height: getSize(32),
          child: AdvancedDropDownSelectWidget(
            key: dropDownKey,
            dropdownStatus: (bool value) {
              setState(() {
                isDropDownOpen.value = value;
              });
            },
            isMandatory: false,
            isMulti: true,
            showSearchIcon: false,
            initiallySelectedItem: null,
            initiallySelectedItemsList: [],
            // Can be populated dynamically
            isAddOnly: false,
            itemList: const [
              "Approved",
              "Rejected",
              "Pending Approval",
              "Verified",
              "Verification Failed"
            ],
            onClear: (bool isCleared) {
              if (isCleared) {
// Handle clear action
                print("Dropdown cleared.");
              }
            },
            onChanged: (List<String>? value) {
// Handle item selection
              print("Selected items: $value");
            },
            decoration: widget.tableDecorationModel ??
                DropDownDecorationModel(
                  fieldHeight: 32,
                  borderRadius: 8,
                  borderColor: Colors.grey,
                  focusedBorderColor: Colors.blue,
                  textStyle: const TextStyle(
                    color: Colors.black,
                    fontSize: 14,
                  ),
                  listItemTextStyle: const TextStyle(
                    color: Colors.black87,
                    fontSize: 12,
                  ),
                  hintText: "Select a status",
                  contentPadding:
                  const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                  dropDownIconSize: 24,
                  iconColor: Colors.black54,
                  itemHoverColor: Colors.blue.shade100,
                  selectedOptionBackgroundColor: Colors.blue.shade50,
                  chipBackgroundColor: Colors.blueGrey.shade50,
                  chipLabelText: const TextStyle(
                    color: Colors.black,
                    fontSize: 12,
                  ),
                  menuBackgroundColor: Colors.white,
                ),
          ),
        ),
      ),
    );
  }
}

// Helper method to calculate size (adjust as needed)
double getSize(double input) {
// Example logic for scaling size (can be device-dependent)
  return input;
}

更多关于Flutter多级选择器插件flutter_multi_selector_drop_down的使用的实战教程也可以访问 https://www.itying.com/category-92-b0.html

phonegap100 1楼

更多关于Flutter多级选择器插件flutter_multi_selector_drop_down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，以下是如何在Flutter项目中使用flutter_multi_selector_drop_down插件来实现多级选择器的示例代码。这个插件允许用户从多个级联的下拉菜单中进行选择。

首先，确保你已经在pubspec.yaml文件中添加了flutter_multi_selector_drop_down依赖：

dependencies:
  flutter:
    sdk: flutter
  flutter_multi_selector_drop_down: ^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，在你的Dart文件中，你可以按照以下方式使用flutter_multi_selector_drop_down：

import 'package:flutter/material.dart';
import 'package:flutter_multi_selector_drop_down/flutter_multi_selector_drop_down.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Multi Selector Drop Down Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MultiSelectorDropDownDemo(),
    );
  }
}

class MultiSelectorDropDownDemo extends StatefulWidget {
  @override
  _MultiSelectorDropDownDemoState createState() => _MultiSelectorDropDownDemoState();
}

class _MultiSelectorDropDownDemoState extends State<MultiSelectorDropDownDemo> {
  List<MultiSelectorItem> _data = [
    MultiSelectorItem(title: 'Fruits', children: [
      MultiSelectorItem(title: 'Apple'),
      MultiSelectorItem(title: 'Banana'),
      MultiSelectorItem(title: 'Cherry'),
    ]),
    MultiSelectorItem(title: 'Vegetables', children: [
      MultiSelectorItem(title: 'Carrot'),
      MultiSelectorItem(title: 'Lettuce'),
      MultiSelectorItem(title: 'Spinach'),
    ]),
  ];

  List<List<int>> _selectedItems = [];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Multi Selector Drop Down Demo'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            MultiSelectorDropDown(
              items: _data,
              onSelectionChanged: (List<List<int>> selectedItems) {
                setState(() {
                  _selectedItems = selectedItems;
                });
              },
              initialSelectedValues: _selectedItems,
              selectorConfig: MultiSelectorConfig(
                displayClearButton: true,
                displaySelectAllButton: true,
                searchEnabled: true,
                searchHintText: 'Search...',
              ),
            ),
            SizedBox(height: 20),
            Text('Selected Items:'),
            SizedBox(height: 10),
            Expanded(
              child: ListView.builder(
                itemCount: _selectedItems.length,
                itemBuilder: (context, index) {
                  List<MultiSelectorItem> selectedPath = [];
                  List<int> path = _selectedItems[index];
                  for (int value in path) {
                    selectedPath.add(_data[path.indexOfFirst((element) => element.value == path[path.indexOf(value) - 1])].children[value]);
                  }
                  return ListTile(
                    title: Text(selectedPath.map((e) => e.title).join(' > ')),
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}

解释

依赖添加：在pubspec.yaml文件中添加flutter_multi_selector_drop_down依赖。
数据准备：准备多级数据，每个MultiSelectorItem可以包含子项。
UI构建：
- 使用MultiSelectorDropDown组件来显示多级选择器。
- 配置MultiSelectorConfig来自定义选择器行为，例如是否显示清除按钮、全选按钮和搜索功能。
- 使用onSelectionChanged回调来处理用户选择的变化。
显示选择结果：将选择的结果显示为一个列表。

这个示例展示了如何使用flutter_multi_selector_drop_down插件来创建一个简单的多级选择器，并根据用户的选择更新UI。你可以根据具体需求进一步定制和扩展这个示例。