设计一个图形界面（GUI）的计算器应用程序，完成简单的算术运算、 设计的计算器应用程序可以完成加法、减法、乘法、除法和取余运算。且有小数点、正负号、求倒数、退格和清零等功能。用鼠标单击相应的数字键和运算符号键，然后单击=按钮，窗口上方的文本框将会显示计算出来的结果，要将文本编辑框清零，可单击清零按钮。-Design a graphical interface (GUI) of the calculator application, complete the simple arithmetic, the calculator application designed to complete the addition, subtraction, multiplication, division and take over operations. And a decimal, sign, seeking the countdown, backspace, and clear functions. Right click the appropriate number keys and operation symbol key, and then click = button, the window will display the text box above the calculated result to the text edit box cleared, click the Clear button.