计算表达式的实现已经有很多了，但是支持含有中文变量名的表达式计算的功能代码我没有找到，因此我抽取一个计算器程序计算表达式的源码，作了一些修改，使之支持含有中文变量名的表达式。-calculation formula has been the realization of a lot, But Chinese support for the variable name contains the expression of functional calculation code, I did not find, So I take a calculated expression calculator source code, made some changes, so that it supports variable names containing the Chinese expression.