使用递归的计算器

Question

这是我的代码，我试图做一个基本的计算器。只有一个文本框，我会写两个数字并添加它们，并像大多数计算器一样将结果放在同一个文本框中。 我的问题是我收到了一个错误：

  

未处理的类型＆＃39; System.StackOverflowException＆＃39;   发生在WindowsFormsApplication1.exe

中

按下按钮+后写下一个号码。

public class calculator
{
    int acum = 0;
    int calcule(int option, int number)
    {
        switch (option)
        {
            case 3:
                acum = acum + number;
                break;
            case 4:
                acum = acum - number;
                break;
            case 5:
                acum = acum * number;
                break;
            case 6:
                acum = acum / number;
                break;
            default:
                break;
        }
        if (number == 0)
        {
            return acum;
        }
        else
        {
            return calculate(option, number);
        }
    }
}

private void btnadd_Click(object sender, EventArgs e)
{
    int numero1 = Convert.ToInt32(txtnumber.Text);

    calculadora calcular = new calculadora();

    txtnumber.Text = calculator.calculate(btnadd.TabIndex, number).ToString();
}

private void btnminus_Click(object sender, EventArgs e)
{
    int numero1 = Convert.ToInt32(txtnumber.Text);

    calculadora calcular = new calculadora();

    txtnumber.Text = calculator.calculate(btnminus.TabIndex, number).ToString();
}

private void button1_Click(object sender, EventArgs e)
{
    int number = Convert.ToInt32(txtnumber.Text);

    calculadora calcular = new calculadora();

    txtnumber.Text = calculator.calculate(button1.TabIndex, number).ToString();
}

private void button2_Click(object sender, EventArgs e)
{
    int numero1 = Convert.ToInt32(txtnumber.Text);

    calculadora calcular = new calculadora();

    txtnumber.Text = calculator.calculate(button2.TabIndex, number).ToString();
}

Answer 1

首先，您的代码中存在许多问题：

1. acum不是静态的，每次你做计算器calc = new Calculator（）;该值设置为零。因此，即使代码中没有错误，结果也会是数字。
2. arg编号的值在计算方法中永远不会改变，所以在这里输入else后，你无法逃脱递归调用（=＆gt; StackOverflowException） if (number == 0) { return acum; } else { return calculate(option, number); }
3. 并且计算（...）是私有的......您无法在类计算器
之外访问它

试试这个：

    enum OperationEnum
    {
        ADD=3,
        SUB=4,
        MUL=5,
        DIV=6
    }
    public class Calculator
    {
        public double Calculate(OperationEnum operation, params int[] operands)
        {
            if (operands == null)
                throw new InvalidOperationException();
            if (operands.Length == 0)
                    return 0;
            if (operands.Length == 1)
                return operands[0];
            switch (operation)
            {
                case OperationEnum.ADD:
                    return Add(operands);
                case OperationEnum.SUB:
                    return Subtract(operands);
                case OperationEnum.MUL:
                    return Multiply(operands);
                case OperationEnum.DIV:
                    return Divide(operands);
                default:
                    throw new ArgumentException("operation");
            }
        }
        private double Divide(int[] operands)
        {
            if (operands.Length == 0)
                return 0;
            var result = operands[0];
            for (int i = 1; i < operands.Length; i++)
            {
                double divider = operands[i];
                if (divider == 0)
                {
                    throw new DivideByZeroException();
                }
                result /= divider;
            }
            return result;
        }
        private double Multiply(int[] operands)
        {
            if (operands.Length == 0)
                return 0;
            double result = operands[0];
            for (int i = 1; i < operands.Length; i++)
            {
                result *= operands[i];
            }
            return result;
        }
        private double Subtract(int[] operands)
        {
            if (operands.Length == 0)
                return 0;
            var result = operands[0];
            for (int i = 1; i < operands.Length; i++)
            {
                result -= operands[i];
            }
            return result;
        }
        private int Add(int[] operands)
        {
            return operands.Sum();
        }
    }
    private double _accumulator = 0;
    private void btnadd_Click(object sender, EventArgs e)
    {
        int numero1 = Convert.ToInt32(txtnumber.Text);
        Calculator calcular = new Calculator();
        _accumulator = calcular.Calculate(OperationEnum.ADD,_accumulator, number);
        txtnumber.Text = _accumulator.ToString()
    }