Flutter实用工具函数插件`lodash_flutter`的使用

lodash_flutter 是一个为Flutter开发者提供的实用工具包，旨在简化开发过程并使算法实现更加有趣。该库受到JavaScript库Lodash的启发，提供了多种常用的数据处理和操作方法。

方法列表

以下是 lodash_flutter 提供的部分方法：

platformVersion
isNullOrBlank
get
chunk
isInteger
isNumeric
toNumber
compact
concat
differenceFromFirst
difference
removeAt
findIndex
findLastIndex
contains
containsfromList
fold
skip
take
join
last
first
isEqual
remove
reverse
slice
subList
sort
uniq
uniqBy
filter
find
groupBy
size
sortedBy
toLowerCase
toupperCase

如果发现缺少某些方法，请在GitHub上创建一个待办事项，以便添加所需功能。

示例代码

下面是一个完整的示例Demo，展示了如何在Flutter应用中使用 lodash_flutter 插件：

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

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  List myList = [];
  List<Map<String, dynamic>> listM = [
    {"title": 'Avengers', "release_date": '10/01/2019'},
    {"title": 'Creed', "release_date": '10/01/2019'},
    {"title": 'Jumanji', "release_date": '30/10/2019'},
  ];

  List<Map<String, dynamic>> sortedByArray = [
    {"fid": 1, "name": "z"},
    {"fid": 10, "name": "b"},
    {"fid": 5, "name": "c"},
    {"fid": 4, "name": "d"}
  ];

  @override
  void initState() {
    super.initState();
    multidimensionArray();
  }

  void multidimensionArray() {
    int N = 10;
    for (int i = 1; i <= N; i++) {
      if (i % 2 == 0) {
        myList.add({'id': i, 'name': "Omi1d", 'abc': 'XYZ'});
        myList.add({'id': i, 'name': "Omi1d--", 'abc': 'XYZ'});
      } else {
        myList.add({'id': 1, 'name': "Omi1d", 'abc': 'XYZ'});
      }
    }
    print(myList);
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('Plugin example app')),
        body: SingleChildScrollView(
          child: Column(
            children: <Widget>[
              Center(child: Text('Check Value is Null: ${LodashFlutter.isNullOrBlank("")}\n')),
              Center(child: Text('isInteger("1"): ${LodashFlutter.isInteger(1)}\n')),
              Center(child: Text('isNumeric("1.2"): ${LodashFlutter.isNumeric(1.2)}\n')),
              Center(child: Text('toNumber("100"): ${LodashFlutter.toNumber("100")}\n')),
              Center(child: Text('Concat: ${LodashFlutter.concat([1], [3])}\n')),
              Center(child: Text('Difference From First: ${LodashFlutter.differenceFromFirst([{'a': 1}, 2, 3], [3, 5, 4])}\n')),
              Center(child: Text('Difference: ${LodashFlutter.difference([{'a': 1}, 2, 3], [3, 5, {'b': 4}])}\n')),
              Center(child: Text('Remove At: ${LodashFlutter.removeAt([1, 2, 3, 4, 5], 2)}\n')),
              Center(child: Text('Find Index: ${LodashFlutter.findIndex(listM, {"title": "Creed"})}\n')),
              Center(child: Text('Find Last Index: ${LodashFlutter.findLastIndex([1, 23, 423, 312, 11, 23, 22, 22, 1], 23)}\n')),
              Center(child: Text('Contains: ${LodashFlutter.contains([1, 2, 3, 4, 6, 7], 5)}\n')),
              Center(child: Text('Fold: ${LodashFlutter.fold([10, 2, 5, 0.5], initialValue: 100)}\n')),
              Center(child: Text('Skip: ${LodashFlutter.skip([10, 2, 5, 0.5], 2)}\n')),
              Center(child: Text('Take: ${LodashFlutter.take([10, 2, 5, 0.5], 4)}\n')),
              Center(child: Text('Join: ${LodashFlutter.join([10, 2, 5, 0.5], "-")}\n')),
              Center(child: Text('Last: ${LodashFlutter.last([10, 2, 5, 0.5])}\n')),
              Center(child: Text('First: ${LodashFlutter.first([10, 2, 5, 0.5])}\n')),
              Center(child: Text('Remove: ${LodashFlutter.remove([{'abx': 1}, {'abx': 2}, {'abx': 3}], [{'abx': 2}])}\n')),
              Center(child: Text('Reverse: ${LodashFlutter.reverse([{'abx': 1}, {'abx': 2}, {'abx': 3}])}\n')),
              Center(child: Text('Slice: ${LodashFlutter.slice([{'abx': 1}, {'abx': 2}, {'abx': 3}], 2)}\n')),
              Center(child: Text('SubList: ${LodashFlutter.subList([{'abx': 1}, {'abx': 2}, {'abx': 3}, {'abx': 4}], 1, 2)}\n')),
              Center(child: Text('Sort: ${LodashFlutter.sort([1, 3, 4, 5, 6, 0])}\n')),
              Center(child: Text('Uniq: ${LodashFlutter.uniq(myList)}\n')),
              Center(child: Text('Uniq By: ${LodashFlutter.uniqBy(myList, "id")}\n')),
              Center(child: Text('Filter: ${LodashFlutter.filter(myList, {"id": 10, "name": "Omi1d", "abc": "XYZ"})}\n')),
              Center(child: Text('Group By: ${LodashFlutter.groupBy(listM, "release_date")}\n')),
              Center(child: Text('Size: ${LodashFlutter.size(listM)}\n')),
              Center(child: Text('Sorted By: ${LodashFlutter.sortedBy(sortedByArray, "fid")}\n')),
              Center(child: Text('Lowercase: ${LodashFlutter.toLowerCase("SDASDSA")}\n')),
              Center(child: Text('Uppercase: ${LodashFlutter.toupperCase("sdasd")}\n')),
              Center(child: Text('Random String: ${LodashFlutter.getRandomString(10, "asABCCSSdsa")}\n')),
            ],
          ),
        ),
      ),
    );
  }
}

如何运行此示例

在您的项目中添加 lodash_flutter 依赖：
```
dependencies:
  lodash_flutter: ^版本号
```

更多关于Flutter实用工具函数插件lodash_flutter的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html

yuanlaile 1楼•10 小时前

更多关于Flutter实用工具函数插件lodash_flutter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，lodash_flutter 是一个为 Flutter 提供类似 Lodash 功能的 Dart 库，它提供了一系列实用的工具函数，可以极大地简化日常开发中的数据处理和操作。以下是一些常见的使用场景和对应的代码案例。

安装 `lodash_flutter`

首先，你需要在 pubspec.yaml 文件中添加 lodash_flutter 依赖：

dependencies:
  flutter:
    sdk: flutter
  lodash_flutter: ^x.y.z  # 请替换为最新版本号

然后运行 flutter pub get 来获取依赖。

常见的使用案例

1. 数组操作

示例：过滤数组

import 'package:flutter/material.dart';
import 'package:lodash_flutter/lodash_flutter.dart' as _;

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    List<int> numbers = [1, 2, 3, 4, 5];
    List<int> evenNumbers = _.filter(numbers, (num) => num % 2 == 0);

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Lodash Flutter Example'),
        ),
        body: Center(
          child: Text('Even Numbers: $evenNumbers'),
        ),
      ),
    );
  }
}

示例：映射数组

List<String> numbersAsStrings = _.map(numbers, (num) => num.toString());

2. 对象操作

示例：获取对象值

import 'package:flutter/material.dart';
import 'package:lodash_flutter/lodash_flutter.dart' as _;

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    Map<String, dynamic> user = {
      'name': 'John',
      'age': 30,
      'address': {
        'city': 'New York',
        'zipcode': '10001'
      }
    };

    String city = _.get(user, 'address.city');

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Lodash Flutter Example'),
        ),
        body: Center(
          child: Text('City: $city'),
        ),
      ),
    );
  }
}

示例：设置对象值

_.set(user, 'address.country', 'USA');

3. 集合操作

示例：合并数组

List<int> array1 = [1, 2, 3];
List<int> array2 = [4, 5, 6];
List<int> mergedArray = _.concat(array1, array2);

示例：查找数组中的唯一值

List<int> mixedArray = [1, 2, 2, 3, 4, 4, 5];
List<int> uniqueArray = _.uniq(mixedArray);

4. 字符串操作

示例：修剪字符串

String str = '   Hello, World!   ';
String trimmedStr = _.trim(str);

示例：拆分字符串

List<String> words = _.split(str, ' ');

总结

lodash_flutter 提供了许多实用的工具函数，可以大大简化数据操作和处理。上述代码案例展示了如何在 Flutter 中使用 lodash_flutter 进行数组、对象、集合和字符串的操作。你可以根据具体需求选择相应的函数进行使用。

请注意，由于 lodash_flutter 的版本和 API 可能会随时间变化，建议查阅最新的官方文档以获取最准确的信息。

Flutter实用工具函数插件lodash_flutter的使用