C#学习8:建一个WPF文件，实现表达式求值，界面比较简陋，添加了一张背景图片，添加背景图片的代码是

<Grid.Background>
            <ImageBrush ImageSource="/表达式求值;component/Images/1.jpg" />
        </Grid.Background>

再修改background的属性即可

输入的表达式形如：((1+2)*5+1)/4=

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace 表达式求值
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        int[,] map = new int[7, 7] {  {1,1,-1,-1,-1,1,1},    // 算符间的优先关系
                                      {1,1,-1,-1,-1,1,1},  
                                      {1,1,1,1,-1,1,1},  
                                      {1,1,1,1,-1,1,1},  
                                      {-1,-1,-1,-1,-1,0,100},  
                                      {1,1,1,1,100,1,1},  
                                      {-1,-1,-1,-1,-1,100,0}  
                                   };
        char[]str=new char[1005];
        char[]optr = new char[1005];
        double[]opnd = new double[1005];
        int t1, t2, k, len;
        char ch, zz;
        int temp1, temp2;
        double a, b;  
        public MainWindow()
        {
            InitializeComponent();
        }
        public int cam(char c)
        {
            switch (c)
            {
                case '+': return 0;
                case '-': return 1;
                case '*': return 2;
                case '/': return 3;
                case '(': return 4;
                case ')': return 5;
                case '#': return 6;
                default: return -1;
            }
        }
        public double sol(double x, char c, double y)
        {
            switch (c)
            {
                case '+': return x + y;
                case '-': return x - y;
                case '*': return x * y;
                case '/': return x / y;
                default: return -1;
            }
        }
        public int z(char c)
        {
            if ('0' <= c && c <= '9' || c == '.')
                return 1;
            if (c == ' ')
                return -1;
            return 0;
        }  
        private void button2_Click(object sender, RoutedEventArgs e)
        {
            this.Close();
        }
        private void button1_Click(object sender, RoutedEventArgs e)
        {
            string s = resource.Text;
            str = s.ToCharArray();
            len = s.Length;
            str[len - 1] = '#'; //处理等于号  
            t1 = t2 = k = 0;
            optr[t1++] = '#';
            ch = str[k++];
            while (ch != '#' || optr[t1 - 1] != '#')
            {
                if (z(ch) == 1)  //操作数入栈  
                {
                    double num1,num2,sm;
                    int t,flagg;
                    num1=num2=0;
                    t=k-1;
                    flagg=0;
                    sm=0.1;
                    while (z(str[t]) == 1)
                    {
                        if (str[t] == '.')
                        {
                            flagg = 1;
                            t++;
                            continue;
                        }
                        if (flagg == 0)
                            num1 = num1 * 10 + (str[t] - '0');
                        else
                        {
                            num2 += sm * (str[t] - '0');
                            sm *= 0.1;
                        }
                        t++;
                    }
                    opnd[t2++]