《JAVA程序设计》实验报告(DOC)(4)

private JTextField resultField; private JButton s1,s2,s3,s4,s5,s6,s7,s8,s9,s0,b1,b2,b3,b4,f1,f2; private boolean end,add,sub,mul,div; private String str; private double num1,num2; public Calculater(){ super(\ setSize(300,240); Container con=getContentPane(); con.setLayout(new BorderLayout()); jPanel1=new JPanel(); jPanel1.setLayout(new GridLayout(1,1)); jPanel2=new JPanel(); jPanel2.setLayout(new GridLayout(4,4)); resultField=new JTextField(\ jPanel1.add(resultField); con.add(jPanel1,BorderLayout.NORTH); s1=new JButton(\ 1 \ s1.addActionListener(this); s2=new JButton(\ 2 \ s2.addActionListener(this); s3=new JButton(\ 3 \ s3.addActionListener(this); s4=new JButton(\ 4 \ s4.addActionListener(this); s5=new JButton(\ 5 \ s5.addActionListener(this); s6=new JButton(\ 6 \ s6.addActionListener(this); s7=new JButton(\ 7 \ s7.addActionListener(this); s8=new JButton(\ 8 \ s8.addActionListener(this); s9=new JButton(\ 9 \ s9.addActionListener(this); s0=new JButton(\ 0 \ s0.addActionListener(this); b1=new JButton(\ + \ b1.addActionListener(this); b2=new JButton(\ - \ b2.addActionListener(this); b3=new JButton(\ * \ b3.addActionListener(this); b4=new JButton(\ / \ b4.addActionListener(this); f1=new JButton(\ . \ f1.addActionListener(this); f2=new JButton(\ = \ f2.addActionListener(this); jPanel2.add(s1); jPanel2.add(s2); jPanel2.add(s3); jPanel2.add(b1); jPanel2.add(s4); jPanel2.add(s5); jPanel2.add(s6); jPanel2.add(b2); jPanel2.add(s7); jPanel2.add(s8); jPanel2.add(s9); jPanel2.add(b3); jPanel2.add(s0); jPanel2.add(f1); jPanel2.add(f2); jPanel2.add(b4); con.add(jPanel2,BorderLayout.CENTER); } public void num(int i){ String s = null; s=String.valueOf(i); if(end){ //如果数字输入结束，则将文本框置零，重新输入 resultField.setText(\ end=false; } if((resultField.getText()).equals(\ //如果文本框的内容为零，则覆盖文本框的内容 resultField.setText(s); } else{ //如果文本框的内容不为零，则在内容后面添加数字 str = resultField.getText() + s; resultField.setText(str); } } public void actionPerformed(ActionEvent e){ //数字事件 if(e.getSource()==s1) num(1); else if(e.getSource()==s2) num(2); else if(e.getSource()==s3) num(3); else if(e.getSource()==s4) num(4); else if(e.getSource()==s5) num(5); else if(e.getSource()==s6) num(6); else if(e.getSource()==s7) num(7); else if(e.getSource()==s8) num(8); else if(e.getSource()==s9) num(9); else if(e.getSource()==s0) num(0); //符号事件 else if(e.getSource()==b1) sign(1); else if(e.getSource()==b2) sign(2); else if(e.getSource()==b3) sign(3); else if(e.getSource()==b4) sign(4); //等号 else if(e.getSource()==f1){ str=resultField.getText(); if(str.indexOf(\ str+=\ resultField.setText(str); } } else if(e.getSource()==f2){ num2=Double.parseDouble(resultField.getText()); if(add){ num1=num1 + num2;} else if(sub){