}; //无左括号
public override string Equal(string strOperator = "+", bool isEqualSign = false)
{
if (!isEqualSign)
{
if (canAddOperator(strOperator))
{
while (RightInput.Length > 0 && (RightInput.IndexOf('.') != -1 &&
sOperatorNum[sOperatorNum.Length - 1] == '0' ||
RightInput[RightInput.Length - 1] == '.'))//删除多余的"."和"0"
{
sOperatorNum = sOperatorNum.Substring(0, sOperatorNum.Length - 1);
RightInput = RightInput.Substring(0, RightInput.Length - 1);
}
sOperatorNum += strOperator;
RightInput = "";
}
}
else
{
if (!isExpressionHolds())
{
return(sOperatorNum);
}
var pts = new Parenthesis();//之后版本中用factory模式代替
pts.Expression = sOperatorNum;
sOperatorNum = pts.CalculatePostfixExp();
}
return(sOperatorNum);
}
/// <summary>
/// 运算符是否能够继续添加
/// </summary>
/// <param name="strOperator"></param>
/// <returns></returns>
private bool canAddOperator(string strOperator)
{
int len = 0;
if (null != sOperatorNum)
{
len = sOperatorNum.Length;
}
if (len == 0)//第一个运算符只能添加左括号
{
if (strOperator == "(" || strOperator == "√")
{
return(true);
}
return(false);
}
var c = sOperatorNum[len - 1];
if (c == '.')
{
sOperatorNum = sOperatorNum.Substring(0, sOperatorNum.Length - 1);
RightInput = RightInput.Substring(0, RightInput.Length - 1);
}
if (strOperator == ")" && !norightphs.Contains(c.ToString())) //右括号只能添加在数字或右括号右边且个数不能大于左括号
{
var leftParenthesis = StrstrCount(sOperatorNum, "(");
var rightParenthesis = StrstrCount(sOperatorNum, ")");
if (leftParenthesis <= rightParenthesis)//左括号个数小于右括号个数不再添加右括号
{
return(false);
}
return(true);
}
else if (strOperator == "(" && norightphs.Contains(c.ToString()))//左括号可以添加在非数字和非右括号的右边
{
return(true);
}
else if ((!norightphs.Contains(c.ToString())) && nphs.Contains(strOperator)) //加减乘除符号可以添加在数字及右括号右边
{
return(true);
}
else
{
return(true);
}
//return false;
}