Flutter计算器功能插件calculator_flutter的使用

Flutter计算器功能插件calculator_flutter的使用

一个简单的Flutter包用于计算数字。

您可以按以下方式执行操作：

Calculator.add(double a, double b)
Calculator.sub(double a, double b)
Calculator.multiply(double a, double b)
Calculator.divide(double a, double b)
Calculator.power(double a, double b)
Calculator.square(double  a)
Calculator.cube(double a)
Calculator.squareRoot(double a)
Calculator.cubeRoot(double a)
Calculator.root(double a,double b)
Calculator.percent(double a,double b)

安装

在您的pubspec.yaml文件中添加以下依赖项：

dependencies:
  calculator_flutter: ^1.0.0

接下来是一个完整的示例代码，展示了如何使用calculator_flutter插件创建一个简单的计算器界面。

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

class CalculatorUI extends StatefulWidget {
  const CalculatorUI({super.key});

  [@override](/user/override)
  CalculatorUIState createState() => CalculatorUIState();
}

class CalculatorUIState extends State<CalculatorUI> {
  String display = "0";
  double? num1;
  double? num2;
  String? operator;

  void buttonPressed(String text) {
    setState(() {
      if (text == "C") {
        // 清除所有数据
        display = "0";
        num1 = num2 = null;
        operator = null;
      } else if (["+", "-", "×", "÷", "^", "√", "∛", "%"].contains(text)) {
        // 设置运算符
        operator = text;
        num1 = double.tryParse(display);
        display = "0";
      } else if (text == "=") {
        // 执行计算
        num2 = double.tryParse(display);
        if (num1 != null && operator != null) {
          switch (operator) {
            case "+":
              // 加法
              display = Calculator.add(num1!, num2!).toString();
              break;
            case "-":
              // 减法
              display = Calculator.sub(num1!, num2!).toString();
              break;
            case "×":
              // 乘法
              display = Calculator.multiply(num1!, num2!).toString();
              break;
            case "÷":
              // 除法
              display = Calculator.divide(num1!, num2!).toString();
              break;
            case "^":
              // 幂运算
              display = Calculator.power(num1!, num2!).toString();
              break;
            case "√":
              // 平方根
              display = Calculator.squareRoot(num1!).toString();
              break;
            case "∛":
              // 立方根
              display = Calculator.cubeRoot(num1!).toString();
              break;
            case "%":
              // 百分比
              display = Calculator.percent(num1!, num2!).toString();
              break;
          }
        }
        operator = null;
      } else {
        // 更新显示
        display = display == "0" ? text : display + text;
      }
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("高级计算器"),
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          Expanded(
            child: Container(
              alignment: Alignment.bottomRight,
              padding: const EdgeInsets.all(20),
              child: Text(
                display,
                style: const TextStyle(fontSize: 48, fontWeight: FontWeight.bold),
              ),
            ),
          ),
          ..._buildKeypad()
        ],
      ),
    );
  }

  List<Widget> _buildKeypad() {
    const keys = [
      ["7", "8", "9", "÷"],
      ["4", "5", "6", "×"],
      ["1", "2", "3", "-"],
      ["C", "0", "=", "+"],
      ["√", "∛", "^", "%"],
    ];

    return keys.map((row) {
      return Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: row.map((key) {
          return ElevatedButton(
            onPressed: () => buttonPressed(key),
            style: ElevatedButton.styleFrom(
              padding: const EdgeInsets.all(16),
              minimumSize: const Size(64, 64),
            ),
            child: Text(key, style: const TextStyle(fontSize: 24)),
          );
        }).toList(),
      );
    }).toList();
  }
}