Flutter货币格式化插件money_formatter的使用

money_formatter 是一个Flutter插件，用于根据您喜欢的特性格式化各种类型的货币，而无需绑定到任何特定的本地化设置。

安装

要安装 money_formatter，请参考 Installation Guide。

使用方法

导入库

import 'package:flutter_money_formatter/flutter_money_formatter.dart';

创建 MoneyFormatter 实例

要将 double 值格式化为您想要的各种格式，首先需要创建一个 MoneyFormatter 实例：

MoneyFormatter fmf = MoneyFormatter(
    amount: 12345678.9012345
);

获取格式化结果

创建实例后，可以请求各种格式化的结果：

// 正常格式
print(fmf.output.nonSymbol); // 12,345,678.90
print(fmf.output.symbolOnLeft); // $ 12,345,678.90
print(fmf.output.symbolOnRight); // 12,345,678.90 $
print(fmf.output.fractionDigitsOnly); // 90
print(fmf.output.withoutFractionDigits); // 12,345,678

// 紧凑格式
print(fmf.output.compactNonSymbol); // 12.3M
print(fmf.output.compactSymbolOnLeft); // $ 12.3M
print(fmf.output.compactSymbolOnRight); // 12.3M $

如果需要多次使用输出格式，建议初始化一个变量：

MoneyFormatterOutput fo = fmf.output;

// 或者直接在初始化时
MoneyFormatterOutput fo = MoneyFormatter(
    amount: 12345678.9012345
).output;

然后可以更方便地获取值：

print(fo.nonSymbol); // 12,345,678.90
print(fo.symbolOnLeft); // $ 12,345,678.90
print(fo.symbolOnRight); // 12,345,678.90 $
print(fo.fractionDigitsOnly); // 90
print(fo.withoutFractionDigits); // 12,345,678

// 紧凑格式
print(fo.compactNonSymbol); // 12.3M
print(fo.compactSymbolOnLeft); // $ 12.3M
print(fo.compactSymbolOnRight); // 12.3M $

配置

可以通过 settings 参数调整格式以满足需求：

MoneyFormatter fmf = new MoneyFormatter(
    amount: 12345678.9012345,
    settings: MoneyFormatterSettings(
        symbol: 'IDR',
        thousandSeparator: '.',
        decimalSeparator: ',',
        symbolAndNumberSeparator: ' ',
        fractionDigits: 3,
        compactFormatType: CompactFormatType.short
    )
);

示例代码

以下是一个完整的示例代码，展示了如何在Flutter应用中使用 money_formatter 插件：

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

void main() => runApp(MyApp());

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

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    TextStyle titleStyle = TextStyle(fontSize: 24.0, fontWeight: FontWeight.bold);
    TextStyle subtitleStyle = TextStyle(fontSize: 20.0);

    MoneyFormatter fmf = MoneyFormatter(amount: 12345678.9012345);
    MoneyFormatterOutput fo = fmf.output;

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Money Formatter Demo'),
        ),
        body: SingleChildScrollView(
          child: ConstrainedBox(
            constraints: BoxConstraints(),
            child: Container(
              padding: EdgeInsets.all(15.0),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: <Widget>[
                  ListTile(
                    title: Text('FormattedNonSymbol :', style: titleStyle),
                    subtitle: Text(fo.nonSymbol, style: subtitleStyle),
                  ),
                  ListTile(
                    title: Text('FormattedLeftSymbol :', style: titleStyle),
                    subtitle: Text(fo.symbolOnLeft, style: subtitleStyle),
                  ),
                  ListTile(
                    title: Text('FormattedRightSymbol :', style: titleStyle),
                    subtitle: Text(fo.symbolOnRight, style: subtitleStyle),
                  ),
                  ListTile(
                    title: Text('FormattedWithoutDecimal :', style: titleStyle),
                    subtitle: Text(fo.withoutFractionDigits, style: subtitleStyle),
                  ),
                  ListTile(
                    title: Text('DecimalOnly :', style: titleStyle),
                    subtitle: Text(fo.fractionDigitsOnly, style: subtitleStyle),
                  ),
                  ListTile(
                    title: Text('FormattedNonSymbolCustom :', style: titleStyle),
                    subtitle: Text(
                      fmf.copyWith(amount: 123.4567, fractionDigits: 4).output.nonSymbol,
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('FormattedLeftSymbolCustom :', style: titleStyle),
                    subtitle: Text(
                      fmf.copyWith(symbol: 'IDR', symbolAndNumberSeparator: '-').output.symbolOnLeft,
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('CompactNonSymbol :', style: titleStyle),
                    subtitle: Text(
                      fmf.copyWith(amount: 12345678987654321.9012345).output.compactNonSymbol,
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('CompactLongNonSymbol :', style: titleStyle),
                    subtitle: Text(
                      fmf.copyWith(
                        amount: 12345678987654321.9012345,
                        compactFormatType: CompactFormatType.long
                      ).output.compactNonSymbol,
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('CompactLeftSymbol :', style: titleStyle),
                    subtitle: Text(
                      fmf.copyWith(amount: 1234.56789).output.compactSymbolOnLeft,
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('CompactRightSymbol :', style: titleStyle),
                    subtitle: Text(
                      fmf.copyWith(
                        amount: 123456.7890,
                        compactFormatType: CompactFormatType.short
                      ).output.compactSymbolOnRight,
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('Fast Calc', style: titleStyle),
                    subtitle: Text(
                      '${MoneyFormatter(amount: 12345.678).fastCalc(type: FastCalcType.addition, amount: 1.111).fastCalc(type: FastCalcType.substraction, amount: 2.222).output.nonSymbol}',
                      style: subtitleStyle,
                    ),
                  ),
                  ListTile(
                    title: Text('Compare IsEqual (=)', style: titleStyle),
                    subtitle: Text(
                      '${fmf.comparator.isEqual(5000)}',
                      style: subtitleStyle,
                    ),
                  )
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}

此示例代码展示了如何在Flutter应用中使用 money_formatter 插件进行货币格式化，并显示了不同格式化选项的结果。