安卓计算器，可实现基本的加减乘除以及正负，能连续运算，还有后退和清除的功能。对于按键的异常也进行了简单的处理操作。工程导入即可运行。-Andrews calculator for basic addition, subtraction, and positive and negative, continuous operation, as well as back and clearing functions. Exceptions are the keys for a simple proce