C#实现简易计算器

C#编写一个简易计算器，供大家参考，具体内容如下

界面

代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections;

namespace calculor
{
public partial class Form1 : Form
{
public Form1()
{
 InitializeComponent();
}

//stack<int> nums;
Stack nums = new Stack();
//stack<char> ops;
Stack ops = new Stack();

//快速幂
int qmi(int a, int b)
{
 int res = 1;

while (b > 0)
 {
 if ((b & 1) == 1) res = res * a;
 a = a * a;
 b >>= 1;
 }

return res;
}

//计算
void Cal()
{
 if (nums.Count <= 1)
 {
 if(ops.Count >= 0)
 {
  ops.Pop();
 }
 return;
 }
 double a = (double)nums.Peek(); nums.Pop();
 double b = (double)nums.Peek(); nums.Pop();
 char c = (char)ops.Peek(); ops.Pop();
 double d = 1;
 if (c == '+') d = a + b;
 else if (c == '-') d = b - a;
 else if (c == '*') d = b * a;
 else if (c == '/')
 {
 if (a == 0)
 {
  MessageBox.Show("Invliad operator");
  return;  
 }
 else
 {
  d = b / a;
 }

}
 else if (c == '％') d = b ％ a;
 else
 {
 d = Math.Pow(b, a);
 }

nums.Push(d);
}

double Calculate(string str)
{
 if (str[0] == '0') str = '0' + str; //-(1 + 1)
 string left = "";
 for (int i = 0; i < str.Length; i++) left += "(";
 str = left + str + ")"; //保证左括号数量大于右括号

for (int i = 0; i < str.Length; i++)
 {
 if (str[i] >= '0' && str[i] <= '9')
 {
  int j = i, tmp = 0; //多位数字
  bool flag = false;
  double t = 0;
  while (j < str.Length && ((str[j] >= '0' && str[j] <= '9') || str[j] == '.'))
  {
  if(str[j] == '.')
  {
   tmp = j;
   j++;
   flag = true;
   continue;
  }
  t = t * 10 + str[j] - '0';
  j++;
  }

i = j - 1;
  if (flag)
  {
  for (int l = 0; l < j - tmp - 1; l++)
  {
   t *= 0.1;
  }
  }
  nums.Push(t);
 }
 else
 {
  char c = str[i];
  if (c == ' ') continue;
  if (c == '(') ops.Push(c);
  else if (c == '+' || c == '-')
  {
  if (c == '-' && i > 0 && !(str[i - 1] >= '0' && str[i - 1] <= '9') && str[i - 1] != ')' && str[i - 1] != ' ') //'-' 代表负号
  {
   if (str[i + 1] == '(') // 将-(...)变成-1 * (...)
   {
   nums.Push(-1);
   ops.Push('*');
   }
   else
   {
   int j = i + 1, tmp = 0;
   double t = 0;
   bool flag = false;
   while (j < str.Length && ((str[j] >= '0' && str[j] <= '9') || str[j] == '.'))
   {
    if (str[j] == '.')
    {
    tmp = j;
    j++;
    flag = true;
    continue;
    }
    t = t * 10 + str[j] - '0';
    j++;
   }

i = j - 1;
   if (flag)
   {
    for (int l = 0; l < j - tmp - 1; l++)
    {
    t *= 0.1;
    }
   }

nums.Push(-t);

}
  }
  else //将 + - 号前面的运算符优先级高的结算，加，减优先级最低。前面都可以结算
  {
   while ((char)ops.Peek() != '(') Cal();
   ops.Push(c);
  }
  }
  else if (c == '*' || c == '/' || c == '％') //将 * / 号前面的运算符优先级高或等于的结算
  {
  while ((char)ops.Peek() == '*' || (char)ops.Peek() == '/' || (char)ops.Peek() == '^' || (char)ops.Peek() == '％') Cal();
  ops.Push(c);
  }
  else if (c == '^') //将 '^' 号前面的运算符优先级高或等于的结算
  {
  while ((char)ops.Peek() == '^') Cal();
  ops.Push(c);
  }
  else if (c == ')') // 将整个括号结算
  {
  while ((char)ops.Peek() != '(') Cal();
  ops.Pop(); //删除'('
  }
  //else MessageBox.Show("invalid operator!");
 }

}

if(nums.Count != 0) return (double)nums.Peek();

return -1;

}

private void Form1_Load(object sender, EventArgs e)
{

}

private void equal_Click(object sender, EventArgs e)
{
 string str = txt_Result.Text;
 double res = Calculate(str);
 if (res == -1)
 {
 txt_Result.Text = "";
 return;
 }
 txt_Result.Text = res.ToString();
}

private void digitOne_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitOne.Text;
}

private void digitTwo_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitTwo.Text;
}

private void digitThree_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitThree.Text;
}

private void digitFour_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitFour.Text;
}

private void digitFive_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitFive.Text;
}

private void digitSix_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitSix.Text;
}

private void digitZero_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitZero.Text;
}

private void digitSeven_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitSeven.Text;
}

private void digitEight_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitEight.Text;
}

private void digitNine_Click(object sender, EventArgs e)
{
 txt_Result.Text += digitNine.Text;
}

private void cal_Sqrt_Click(object sender, EventArgs e)
{
 string str = txt_Result.Text;
 double res = Calculate(str);
 if (res == -1)
 {
 txt_Result.Text = "";
 return;
 }
 if (res < 0)
 {
  MessageBox.Show("{数据不合法");
 txt_Result.Text = "";
 return;
 }
 double res1 = Math.Sqrt(res);
 txt_Result.Text = res1.ToString();
}

private void Dot_Click(object sender, EventArgs e)
{
 txt_Result.Text += Dot.Text;
}

private void cal_Multi_Click(object sender, EventArgs e)
{
 txt_Result.Text += cal_Multi.Text;
}

private void cal_Sub_Click(object sender, EventArgs e)
{
 txt_Result.Text += cal_Sub.Text;
}

private void cal_Add_Click(object sender, EventArgs e)
{
 txt_Result.Text += cal_Add.Text;
}

private void cal_Rem_Click(object sender, EventArgs e)
{
 txt_Result.Text += cal_Rem.Text;
}

private void left_brack_Click(object sender, EventArgs e)
{
 txt_Result.Text += left_brack.Text;
}

private void right_brack_Click(object sender, EventArgs e)
{
 txt_Result.Text += right_brack.Text;
}

private void cal_log_Click(object sender, EventArgs e)
{
 string str = txt_Result.Text;
 double res = Calculate(str);
 if (res == -1)
 {
 txt_Result.Text = "";
 return;
 }
 if (res < 0)
 {
 MessageBox.Show("{数据不合法");
 txt_Result.Text = "";
 return;
 }
 double res1 = Math.Log(res);
 txt_Result.Text = res1.ToString();
}

private void btn_Clear_Click(object sender, EventArgs e)
{
 txt_Result.Text = "";
}

private void cal_mi_Click(object sender, EventArgs e)
{
 txt_Result.Text += cal_mi.Text;
}

private void cal_Div_Click(object sender, EventArgs e)
{
 txt_Result.Text += cal_Div.Text;
}

private void btn_backspace_Click(object sender, EventArgs e)
{
 string str = txt_Result.Text;
 string newStr = "";
 int len = str.Length;
 if (len > 0)
 {
 for(int i = 0; i < len - 1; i++)
 {
  newStr += str[i];
 }
 }
 txt_Result.Text = newStr;
}
}
}

来源：https://blog.csdn.net/xiaoxiongyuan__s/article/details/112349461