/// <summary>
/// 计算后缀表达式
/// </summary>
/// <param name="value">后缀表达式</param>
/// <returns></returns>
public static Object Calculate(Stack <Object> value)
{
Stack <Object> post = new Stack <Object>();
while (value.Count > 0)
{
post.Push(value.Pop());
}
Stack <Object> stack = new Stack <Object>();
while (post.Count > 0)
{
Object obj = post.Pop();
if (obj != null && obj.GetType().FullName == "FivePower.Web.FPTemplate.Operator")
{
Object y = stack.Pop();
Object x = stack.Pop();
stack.Push(Calculate(x, y, OperatorConvert.ToString((Operator)obj)));
}
else
{
stack.Push(obj);
}
}
return(stack.Pop());
}
/// <summary>
/// 处理表达式
/// </summary>
/// <param name="value">表达式</param>
/// <returns></returns>
public static Stack <Object> ProcessExpression(String value)
{
value = value.Replace(" ", String.Empty);
List <Object> result = new List <Object>();
Int32 j = 0;
Int32 i;
String num;
for (i = 0; i < value.Length; i++)
{
switch (value[i])
{
case '+':
case '-':
case '*':
case '/':
case '(':
case ')':
case '%':
if (j < i)
{
num = value.Substring(j, i - j);
if (num.IndexOf('.') == -1)
{
result.Add(Int32.Parse(value.Substring(j, i - j)));
}
else
{
result.Add(Double.Parse(value.Substring(j, i - j)));
}
j = i;
}
result.Add(OperatorConvert.Parse(value[i].ToString()));
j++;
break;
}
}
if (j < i)
{
result.Add(Double.Parse(value.Substring(j, i - j)));
}
return(ProcessExpression(result.ToArray()));
}
