简易计算器的设计，文本框text1作为计算器的显示屏幕，再建立几组按钮数组，通过对按钮数组的设置来设置每一个按钮的功能。-Simple calculator design, the text box text1 as a calculator display screen, and then build an array of several groups of buttons, by setting an array of buttons to set each button function