编程实现一个简易计算器，实现基本的加减乘除运算功能

//在计算器的面板上，有0—9数字的按钮，同时还有加减乘除的运算按钮已经清空运算框按钮，用户可以直接点击

//面板进行输入数字并计算，输入和输出结果数据共用一个文本框

//当进行除法运算时当除数为0，计算器会给出错误提示-Programming a simple calculator for basic operations of addition and subtraction multiplication and division functions// in the calculator panel, there are 0-9 figures a button, along with addition and subtraction multiplication and division operations computing the button box button has been empty, the user can Direct Hits// panel to enter a number and calculation, input and output data sharing in a text box// When it comes to when the division operation when the divisor is 0, the calculator will give error