C#带小括号的运算

计算类的封装

jisuan.cs

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace ZY四则运算
 {
     public class jisuan
     {
         public Dictionary<char, int> priorities = null;  //优先级

         public void Calculator()    //添加了四种运算符以及四种运算符的优先级
         {
             priorities = new Dictionary<char, int>();
             priorities.Add();
             priorities.Add();
             priorities.Add();
             priorities.Add();
             priorities.Add();
         }

         const string operators = "+-*/";      //运算符

         public double Compute(double leftNum, double rightNum, char op)  //这是一种方法，用来计算左右两个数的静态方法！
         {
             switch (op)
             {
                 case '+': return leftNum + rightNum;
                 case '-': return leftNum - rightNum;
                 case '*': return leftNum * rightNum;
                 case '/': return leftNum / rightNum;
                 ;
             }
         }

         public bool IsOperator(char op)  //每次判断这个字符是否是运算符？
         {
             ;
         }

         public bool IsAssoc(char op)    //返回一个关联符号
         {
             return op == '+' || op == '-' || op == '*' || op == '/';
         }

         public  Queue<object> QueueSort(string expression)   // 队列排序
         {
             Queue<object> result = new Queue<object>();
             Stack<char> operatorStack = new Stack<char>();   //运算符栈
             operatorStack.Push('#');
             char top, cur, tempChar;                    //top栈顶，current最近的；
             string tempNum;
             , j; i < expression.Length; )     //取出表达式
             {
                 cur = expression[i++];                 //取出表达式的每个字符赋给cur
                 top = operatorStack.Peek();        //栈顶元素赋给top此时为"#"

                 if (cur == '(')         //将左括号压栈,此时栈顶元素为"("
                 {
                     operatorStack.Push(cur);
                 }
                 else
                 {
                     if (IsOperator(cur))       //如果是运算符的话
                     {
                         while (IsOperator(top) && ((IsAssoc(cur) && priorities[cur] <= priorities[top])) || (!IsAssoc(cur) && priorities[cur] < priorities[top]))
                         {
                             result.Enqueue(operatorStack.Pop());     //如果元素为运算符并且优先级小于栈顶元素优先级，出栈
                             top = operatorStack.Peek();      //继续把栈顶元素赋给top
                         }
                         operatorStack.Push(cur);      //把数字压栈
                     }
                     else if (cur == ')')       //将右括号添加到结尾
                     {
                          && (tempChar = operatorStack.Pop()) != '(')
                         {
                             result.Enqueue(tempChar);
                         }
                     }
                     else
                     {
                         tempNum = "" + cur;
                         j = i;
                         ')))
                         {
                             tempNum += expression[j++];
                         }
                         i = j;
                         result.Enqueue(tempNum);
                     }
                 }
             }
             )
             {
                 cur = operatorStack.Pop();
                 if (cur == '#') continue;
                 )
                 {
                     top = operatorStack.Peek();
                 }

                 result.Enqueue(cur);
             }

             return result;
         }

         public  double Calucate(string expression)
         {
             try
             {
                 var rpn = QueueSort(expression);
                 Stack<double> operandStack = new Stack<double>();
                 double left, right;
                 object cur;
                 )
                 {
                     cur = rpn.Dequeue();        //出列
                     if (cur is char)            //如果cur为字符的话
                     {
                         right = operandStack.Pop();   //右边的数字出栈
                         left = operandStack.Pop();    //左边的数字出栈
                         operandStack.Push(Compute(left, right, (char)cur));    //此时调用compute方法
                     }
                     else
                     {
                         operandStack.Push(double.Parse(cur.ToString()));      //是数字就压栈
                     }
                 }
                 return operandStack.Pop();
             }
             catch
             {
                 throw new Exception("表达式不正确！");
             }
         }
     }
 }

Form1.cs

 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;
 using System.IO;

 namespace ZY四则运算
 {
     public partial class Form1 : Form
     {
         Form2 frm2 = new Form2();
         public Form1()
         {
             InitializeComponent();
         }
         private void button1_Click_1(object sender, EventArgs e)
         {
             string Express = textBox1.Text;
             frm2.listBox1.Items.Add(Express);
             listBox1.Items.Add(" " + Express + "=");
             textBox1.Clear();
         }
         private void button2_Click(object sender, EventArgs e)
         {
             frm2.ShowDialog();
         }
     }
 }

Form2.cs

 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;
 using System.IO;

 namespace ZY四则运算
 {
     public partial class Form2 : Form
     {
         public Form2()
         {
             InitializeComponent();
         }
         ; //倒计时
         ;
         ;
         private void Form2_Load(object sender, EventArgs e)
         {
             lblTime.Text = "剩余时间：";
             timer1.Enabled = false;
             timer1.Interval = ;
         }
         private void timer1_Tick(object sender, EventArgs e)
         {
             int tm = time--;
             lblTime.Text = "剩余时间：" + tm.ToString() + "秒";
             )
             {
                 timer1.Enabled = false;
                 MessageBox.Show("时间已到", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
             }
         }
         private void button1_Click_1(object sender, EventArgs e)
         {
             timer1.Stop();
             MessageBox.Show(label1.Text);
         }
         private void button2_Click_1(object sender, EventArgs e)
         {
             timer1.Start();
         }
         private void button3_Click_1(object sender, EventArgs e)
         {
             sfd.Filter = "(*.txt)|*.txt";
             if (sfd.ShowDialog() == DialogResult.OK)
             {
                 string sPath = sfd.FileName;
                 FileStream fs = new FileStream(sPath, FileMode.Create);
                 StreamWriter sw = new StreamWriter(fs, Encoding.UTF8);
                 ;
                 ; i <= iCount; i++)
                 {
                     sw.WriteLine(listBox2.Items[i].ToString());
                 }
                 sw.Flush();
                 sw.Close();
                 fs.Close();
             }
         }
         private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
         {
             )
             {
                 textBox1.Text = listBox1.Items[].ToString();
             }
             else
             {
                 MessageBox.Show("答题结束");
             }
         }
         private void textBox2_KeyDown(object sender, KeyEventArgs e)
         {
             jisuan js = new jisuan();
             if (e.KeyCode == Keys.Enter)
             {
                 string result = textBox1.Text;
                 if (textBox2.Text.Trim() == string.Empty)            //去除空格之后，如果没答题给出提示。
                 {
                     MessageBox.Show("您尚未答题", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                     return;
                 }
                 Count++;
                 if (textBox2.Text ==js.Calucate(result).ToString())   //直接调用Calucate这个方法计算result的值并与输入的值进行比较
                 {
                     MessageBox.Show("回答正确！");
                     listBox2.Items.Add(result + "=" + textBox2.Text + "  " + "√");//若答对直接后面打个对勾。
                     listBox1.Items.Remove(listBox1.SelectedItem);
                     right++;
                 }

                 else
                 {
                     MessageBox.Show("答题错误！");
                     listBox2.Items.Add(result + "=" + textBox2.Text + "  " + "×");//若答错就在后面打个错号。
                     listBox1.Items.Remove(listBox1.SelectedItem);
                 }
                 label1.Text = ).PadRight(, , ) + "%";
                 textBox1.Clear();
                 textBox2.Clear();
             }
         }
     }
 }

运行测试：

出题界面：

答题界面：

提示结束：

保存：