C#作业——表达式计算器+小数点

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 WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public String expression;
        public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            expression = textBox1.Text;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text = expression + "=" + Result(expression);
        }
        private double Result(String expression)
        {
            int length = expression.Length;
            char[] a = expression.ToCharArray(0, length);
            double[] data = new double[10];
            char[] oper = new char[10];
            int datacount = 0, opercount = 0;
            double temp = 0;
            int dicimal = -1;
            double tempdi=1;
            for (int m = 0; m < length; m++)
            {

                if (Char.IsDigit(a[m]) == true)
                {

                    if (dicimal == -1)
                    {
                        temp *= 10;
                        temp += a[m] - '0';
                    }
                    else
                    {
                        dicimal++;
                        for (int q = 0; q < dicimal; q++)
                            tempdi = tempdi * 0.1;
                        temp = temp + (a[m] - '0') * tempdi;

                    }

                }
                else if (a[m] == '.')
                {
                    dicimal = 0;
                }
                else
                {
                    dicimal = -1;
                    tempdi = 1;
                    data[datacount] = temp;
                    datacount++;
                    temp = 0;
                    oper[opercount] = a[m];
                    opercount++;
                }
                }
                
                data[datacount] = temp;
                datacount++;

                int temp1 = 0;
                int tempdata = 0;
                while (temp1 < opercount)
                {
                    double para1 = data[tempdata];
                    tempdata++;
                    double para2 = data[tempdata];
                    if (oper[temp1] == '+')
                    { data[tempdata] = para1 + para2; }
                    else if (oper[temp1] == '-')
                    { data[tempdata] = para1 - para2; }
                    else if (oper[temp1] == '*')
                    { data[tempdata] = para1 * para2; }
                    else if (oper[temp1] == '/')
                    { data[tempdata] = para1 / para2; }
                    temp1++;

                }

                return data[tempdata];

            }
        }
    }