文件名称：计算器（可用于表达式的值）
文件大小：920B
文件格式：SLN
更新时间：2013-07-07 16:46:38
计算器
C#程序，巧用栈的基本操作！源代码如下：
public FrmCalculator()
{
InitializeComponent();
}
private string str = "";
private void FrmCalculator_Load(object sender, EventArgs e)
{
txtCalculate.Text = "";
}
/* private void btn1_Click(object sender, EventArgs e)
{
str += "7";
txtCalculate.Text = str.ToString();
// txtCalculate.Text += Convert.ToString(7);
}
private void btn2_Click(object sender, EventArgs e)
{
str += "8";
txtCalculate.Text = str.ToString();
// txtCalculate.Text += Convert.ToString(8);
}
private void btn3_Click(object sender, EventArgs e)
{
str += "9";
txtCalculate.Text = str.ToString();
// txtCalculate.Text += "9";
}
private void btn5_Click(object sender, EventArgs e)
{
str += "4";
txtCalculate.Text = str.ToString();
// txtCalculate.Text += "4";
}
private void btn6_Click(object sender, EventArgs e)
{
str += "5";
txtCalculate.Text = str.ToString();
// txtCalculate.Text += "5";
}
private void btn7_Click(object sender, EventArgs e)
{
str += "6";
txtCalculate.Text = str.ToString();
}
private void btn9_Click(object sender, EventArgs e)
{
str += "1";
txtCalculate.Text = str.ToString();
}
private void btn10_Click(object sender, EventArgs e)
{
str += "2";
txtCalculate.Text = str.ToString();
}
private void btn11_Click(object sender, EventArgs e)
{
str += "3";
txtCalculate.Text = str.ToString();
}
private void tn13_Click(object sender, EventArgs e)
{
str += "0";
txtCalculate.Text = str.ToString();
}
private void btn4_Click(object sender, EventArgs e)
{
str += "+";
txtCalculate.Text = str.ToString();
}
private void btn8_Click(object sender, EventArgs e)
{
str += "-";
txtCalculate.Text = str.ToString();
}
private void btn12_Click(object sender, EventArgs e)
{
str += "*";
txtCalculate.Text = str.ToString();
}
private void btn16_Click(object sender, EventArgs e)
{
str += "/";
txtCalculate.Text = str.ToString();
}
private void btn14_Click(object sender, EventArgs e)
{
str += "(";
txtCalculate.Text = str.ToString();
}
private void btn15_Click(object sender, EventArgs e)
{
str += ")";
txtCalculate.Text = str.ToString();
}
*/
private void button2_Click(object sender, EventArgs e)
{
str = "";
txtCalculate.Text = "";
//txtCalculate.SelectionStart;
txtCalculate.Focus();
}
private char Precede(char x, char y)
{
char Ch = ' ';
char[] ch = { '+', '-', '*', '/', '(', ')', '#' };
for (int i = 0; i < 7; i++)
{
if (x != ch[i]) Ch = 'E';
if (y != ch[i]) Ch = 'E';
}
if (x == '+' || x == '-')
{
if (y == '+' || y == '-' || y == ')' || y == '#') Ch = '>';
else Ch = '<';
}
else if (x == '*' || x == '/')
{
if (y == '(') Ch = '<';
else Ch = '>';
}
else if (x == '(')
{
if (y == ')') Ch = '=';
else Ch = '<';
}
else if (x == ')') Ch = '>';
else if (x == '#')
{
if (y == '#') Ch = '=';
else Ch = '<';
}
return Ch;
}
private double Operate(double a, char theta, double b)
{
switch (theta)
{
case '+': return a + b;
case '-': return a - b;
case '*': return a * b;
case '/': return a / b;
default: return 0;
}
}
private bool In(char ch)
{
bool b;
if (ch == '+' || ch == '-' || ch == '*' || ch == '/' || ch == '(' || ch == ')' || ch == '#')
b = true;
else
b = false;
return b;
}
private double Getnum(string s, ref int i)
{
double x = 0;
double l = 0;
int j = i, k;
while (s[j] != '\0' && !In(s[j]))
{
if (s[j] == '.') { k = j; break; }
else j++;
}
k = j;
double d = 10;
while (s[i] != '\0' && !In(s[i]))
{
if (i < k)
x = x * 10 + s[i] - '0';
else if (i == k)
{
i++;
continue;
}
else
{
l += ((s[i] - '0') / d);
d *= 10;
}
i++;
}
// i--;s
return x + l;
}
private double EvaluateExpression(string s)
{
s = s.Insert(0, "#"); //字符串变量的insert属性用于将一段字符串插入到指定位置
s = s.Insert(s.Length, "#"); //append属性将一段字符串插入到已知字符串的末尾
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