[英]C# Calculator Class
我得到了这份家庭作业,这让我很辛苦。 表格已经写好了,我们不得不写课。 当前,当我运行程序时,我的equals按钮似乎无法正常工作。 我不确定为什么,我想知道是否有人可以帮助我了解我的缺失。 我相信我的课堂写得正确。 在我的脑海中,发生了什么事,计算器将其称为“ currentValue”,因此我不断更新自己在运算符中使用的方法。
我的方向正确吗?
为什么我的equals按钮不调用当前值。 上次运行此命令时,如果键入9 + 3 +,则显示屏将填充12,并等待我输入下一个数字。 那么从理论上讲,为什么我的等号按钮不会加载答案? 我相信我打的是正确的物品,但我一直保持着最初的名字。 例如,如果我输入9 + 9并命中=我继续得到9。
这是计算器代码(提供的部分):
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Calculator
{
public partial class frmCalculator : Form
{
public frmCalculator()
{
InitializeComponent();
}
// The following fields are used to store the value that's currently
// displayed by the calculator. displayString is a string value that's
// constructed as the user clicks numeric keys and the decimal and +/-
// key. The Convert.ToDecimal method is then used to convert this to a decimal
// field that's stored in displayValue.
private string displayString;
private decimal displayValue;
// The following bool fields are used to control numeric entry.
// newValue indicates whether the calculator is ready to receive a
// new numeric value. Once the user clicks a digit button, newValue is
// set to false. When the user clicks a button that "enters" the value,
// such as Add or Equals, newValue is set to true so the user can enter
// another value.
// decimalEntered is used to restrict the entry to a single decimal point.
// It is set to true whenever newValue is set to true, and it is set to
// false whenever the user clicks the decimal point button.
private bool newValue;
private bool decimalEntered;
private Calculator calc = new Calculator();
private void Form1_Load(object sender, System.EventArgs e)
{
displayValue = 0;
displayString = displayValue.ToString();
newValue = true;
decimalEntered = false;
}
// This method handles the 0 through 9 keys, appending the digit clicked
// to the displayString field.
private void btnNumber_Click(object sender, System.EventArgs e)
{
if (newValue)
{
displayString = "";
newValue = false;
}
displayString += ((Button)sender).Tag.ToString();
displayValue = Convert.ToDecimal(displayString);
txtDisplay.Text = displayValue.ToString();
}
// This method removes the last character from the displayString field.
private void btnBackSpace_Click(object sender, System.EventArgs e)
{
if (displayString.Length > 1)
{
displayString = displayString.Substring(0, displayString.Length - 1);
displayValue = Convert.ToDecimal(displayString);
txtDisplay.Text = displayValue.ToString();
}
else
{
displayString = "";
displayValue = 0;
txtDisplay.Text = displayValue.ToString();
}
}
private void btnClear_Click(object sender, System.EventArgs e)
{
calc.Clear();
displayString = "";
displayValue = 0;
txtDisplay.Text = displayValue.ToString();
newValue = true;
decimalEntered = false;
}
// This method appends a decimal point to the displayString field if the
// user has not already entered a decimal point.
private void btnDecimal_Click(object sender, System.EventArgs e)
{
if (newValue)
{
displayString = "0";
newValue = false;
}
if (!decimalEntered)
{
displayString += ".";
displayValue = Convert.ToDecimal(displayString);
txtDisplay.Text = displayValue.ToString();
decimalEntered = true;
}
}
private void btnSign_Click(object sender, System.EventArgs e)
{
displayValue = -displayValue;
txtDisplay.Text = displayValue.ToString();
}
private void btnAdd_Click(object sender, System.EventArgs e)
{
calc.Add(displayValue);
newValue = true;
decimalEntered = false;
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
}
private void btnSubtract_Click(object sender, System.EventArgs e)
{
calc.Subtract(displayValue);
newValue = true;
decimalEntered = false;
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
}
private void btnMultiply_Click(object sender, System.EventArgs e)
{
calc.Multiply(displayValue);
newValue = true;
decimalEntered = false;
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
}
private void btnDivide_Click(object sender, System.EventArgs e)
{
calc.Divide(displayValue);
newValue = true;
decimalEntered = false;
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
}
private void btnSqrt_Click(object sender, System.EventArgs e)
{
calc.SquareRoot(displayValue);
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
}
private void btnReciprocal_Click(object sender, System.EventArgs e)
{
try
{
calc.Reciprocal(displayValue);
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
}
catch (DivideByZeroException)
{
displayValue = 0;
txtDisplay.Text = "Cannot divide by zero.";
newValue = true;
decimalEntered = false;
}
}
private void btnEquals_Click(object sender, System.EventArgs e)
{
try
{
if (newValue)
calc.Equals();
else
calc.Equals(displayValue);
displayValue = calc.CurrentValue;
txtDisplay.Text = displayValue.ToString();
newValue = true;
decimalEntered = false;
}
catch (DivideByZeroException)
{
displayValue = 0;
txtDisplay.Text = "Cannot divide by zero.";
newValue = true;
decimalEntered = false;
}
}
}
}
这是我的课(我写的部分):
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Calculator
{
public class Calculator
{
public Decimal displayValue;
public Decimal currentValue;
public void Add(Decimal displayValue)
{
currentValue += displayValue;
}
public void Subtract(Decimal displayValue)
{
currentValue -= displayValue;
}
public void Multiply(Decimal displayValue)
{
currentValue *= displayValue;
}
public void Divide(Decimal displayValue)
{
currentValue /= displayValue;
}
public void SquareRoot(Decimal displayValue)
{
currentValue = (decimal)Math.Sqrt(Convert.ToDouble(displayValue));
}
public void Reciprocal(Decimal displayValue)
{
currentValue = 1 / displayValue;
}
public decimal Equals()
{
return currentValue;
}
public void Clear()
{
currentValue = 0;
displayValue = 0;
}
public decimal CurrentValue
{
get
{
return currentValue;
}
}
}
}
在主代码中,您像这样调用了Equal()方法:
if (newValue)
calc.Equals();
else
calc.Equals(displayValue); //Your class do not have this.
所以,你应该先做
//I am not sure why you need to pass in the displayValue parameter, so I presume it would not return anything.
public void Equal(Decimal displayValue)
{
//Do the things you suppose to do
}
对于9 + 9 = 9的问题,这仅仅是因为在您的代码中,您只按下了一次单击事件Add_Button。 在您的Add()
方法上创建一个断点。 然后尝试这样做:
9->按下您的Add_Button-> 9->按下您的Add_Button->检查您的currentValue
displayValue
既是类字段又是方法参数。 那是你的意图吗? 分配给field参数时,需要使this.displayValue = ...
以使其清楚您在做什么。 当前,您正在覆盖参数的本地副本,并且字段值始终为0。
只需删除decimal displayValue;
声明(以及从Clear()
函数),然后将displayValue存储在表单之外的类之外。
public class Calculator
{
//public Decimal displayValue;
public Decimal currentValue;
public void Add(Decimal displayValue)
{
currentValue+=displayValue;
}
...
public void Clear()
{
currentValue=0;
//displayValue=0;
}
public decimal CurrentValue
{
get { return currentValue; }
}
}
class Program
{
static void Main(string[] args)
{
Calculator calc=new Calculator();
calc.Add(1000m);
calc.Divide(25m);
calc.Subtract(8m);
Console.WriteLine(calc.CurrentValue);
// (1000/25)-8 = 32
}
}
我在代码中看到的主要问题是您只添加了一个操作数,例如8 + 8总是等于8,您必须执行以下操作(仅包括Add和倒数函数):
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Calculator
{
public class Calculator
{
public Decimal displayValue;
public Decimal currentValue;
private Decimal Operand_1;
private Decimal Operand_2;
private bool Operand_1_Added = false;
private bool Operand_2_Added = false;
private string Operation = "";
private void AddOperand(Decimal Operand)
{
if(Operand_1_Added)
{
Operand_2 = Operand;
Operand_2_Added = true;
}
else {
Operand_1 = Operand;
Operand_1_Added = true;
currentValue = Operand_1;
}
}
public void Add(Decimal Arg1)
{
this.AddOperand(Arg1);
Operation = "Addition";
}
public void Reciprocal(Decimal Arg)
{
this.AddOperand(Arg);
Operation = "Reciprocal";
}
public void Clear()
{
currentValue = 0;
displayValue = 0;
Operand_1 = 0;
Operand_2 = 0;
}
public void Equals()
{
switch(Operation)
{
case "Addition":
currentValue = Operand_1 + Operand_2;
break;
case "Reciprocal":
currentValue = 1/Operand_1;
break;
default: break;
}
}
public void Equal(Decimal displayValue)
{
currentValue = displayValue;
}
public decimal CurrentValue
{
get
{
return currentValue;
}
}
}
尚未测试代码,但这应该与form类一起使用。
让我们看一下需求:
“乘法运算的结果应显示的小数位数不应少于第一个数字的结果,而不是第二个数字。示例55.5 * 89.68 = 4977.240”
基本算术中乘法的自然含义是默认情况下都会发生这种情况。 例如。 您永远不会将XX与X.XX相乘,而得到结果X.XXXXXXX ...-这简直是不可能的。
因此,格式化很容易-如果您需要显式格式化,则将其格式化为num.ToString(“#。##############”),这样可以保留一堆数字。
您尚未概述“划分”的任何要求,因此我无法发表评论。
顺便说一句-如果您说x = 1/3和y = z * x,那么您将在小数点后得到很多数字,因为x开头是.333333333...。 这在AFAICT的要求之内。
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