C＃计算器类 [英] C# Calculator Class
问题描述
我得到了这个家庭作业，我一直有一个困难时期。形式是书面，我们不得不写的类。目前，当我运行程序我的等号按钮不会出现奏效。我不确定为什么，我想知道，如果有人可以帮助我了解我错过了什么。我相信我已经正确地写入我的课。在我的头是怎么回事，是计算器调用CurrentValue的，所以我不断地与我使用我的运营商的方法更新。
I was given this homework assignment, which I have been having a hard time with. The form was written and we had to write the class. Currently when I run the program my equals button does not appear to be working. I'm unsure why and I was wondering if someone could help me understand what I am missing. I believe I have written my class correctly. In my head what is going on is the calculator is calling the "currentValue" so I am constantly updating with the method I am using in my operators.
我是在正确的方向？
为什么不是我等于按钮调用当前值。上次我跑了这一点，如果我输入9 + 3 +然后我会展示12个填充，待我输入一个号码。因此，在理论上为什么不是我的等号按钮加载答案吗？我相信我打电话正确的项目，但我一直得到我最初的条目。举例来说，如果我输入9 + 9 =打我不断收到9.
And why isn't my equals button calling the current value. The last time I ran this, if I typed 9 + 3 + then my display would populate with 12 and wait for me to enter the next number. So in theory why wouldn't my equals button load the answer? I believe I am calling the correct item yet I keep getting my initial entry. For instance if I typed 9 + 9 and hit = I keep getting 9.
下面是计算器代码（提供的部分）：
Here is the calculator code (the part provided):
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;
}
}
}
}
}
下面是我的课（我写的一部分）：
Here is my class (The part I wrote):
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;
}
}
}
}
}
推荐答案
在主代码，你有人称这样的平等（）方法：
In the main code, you have called the Equal() method like this:
if (newValue)
calc.Equals();
else
calc.Equals(displayValue); //Your class do not have this.
所以，你应该这样做首先
So, you should do this first
//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
}
和你的9 + 9 = 9的问题，原因很简单，在你的代码，你只按点击事件ADD_BUTTON一次。做一个破发点你的添加（）方法。然后试着这样做：
And for your 9 + 9 = 9 problem, it is simply because in your code, you only press your click event Add_Button for once. Make a break point at your Add() method. Then try to do like this:
9 - >按你的ADD_BUTTON - > 9 - >按你的ADD_BUTTON - >检查您的CurrentValue的
9 --> press your Add_Button --> 9 --> press your Add_Button --> check your currentValue
这篇关于C＃计算器类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
