java 计算器

JFrame frame=new JFrame("计算器"); JPanel panel1=new JPanel(); JPanel panel2=new JPanel(); JButton btn0=new JButton("0"); JButton btn1=new JButton("1"); JButton btn2=new JButton("2"); JButton btn3=new JButton("3"); JButton btn4=new JButton("4"); JButton btn5=new JButton("5"); JButton btn6=new JButton("6"); JButton btn7=new JButton("7"); JButton btn8=new JButton("8"); JButton btn9=new JButton("9"); JButton jia=new JButton("+"); JButton jian=new JButton("-"); JButton cheng=new JButton("x"); JButton chu=new JButton("/"); JButton dengyu=new JButton("="); JButton qingchu=new JButton("C");