表达式计算代码,按优先级计算输入的表达式,支持括号,阶乘号,暂不支持三角函数！--Expression calculating code, it can calculate inputed expression by priority ,and supports parenthesis, factorial sign, and it does not support trigonometrical functions for now!

圆角按钮的，超级漂亮啊，有需要的要顶啊，只有一福图片就搞定-Rounded buttons, super nice ah, there is a need to Dinga, xxx