实验十一-————>图形界面（监听）

  1 package 计算器;
  2 import java.awt.*;
  3 import java.awt.event.*;
  4 import javax.swing.*;
  5 import java.awt.Dimension;
  6 import java.math.*; 
  7 public class mine extends JFrame implements ActionListener 
  8 {     
  9     int f = 0, fd = 0;    
 10     double a = 0, b = 0;    
 11     double t = 10.0;    
 12     JPanel pan1 = new JPanel();    
 13     JPanel pan2 = new JPanel(new GridLayout(5, 3, 1, 3));
 14 //网状布局，5行3列  平行间距1mm 垂直间距3mm
 15     JTextField tf = new JTextField();//文本行
 16    //定义一系列按钮
 17 JButton bu0 = new JButton("0");
 18 JButton bu1 = new JButton("1");    
 19 JButton bu2 = new JButton("2");
 20 JButton bu3 = new JButton("3");    
 21 JButton bu4 = new JButton("4");
 22 JButton bu5 = new JButton("5");    
 23 JButton bu6 = new JButton("6");
 24 JButton bu7 = new JButton("7");
 25 JButton bu8 = new JButton("8");
 26 JButton bu9 = new JButton("9"); 
 27 JButton bu_jia = new JButton("+");
 28 JButton bu_jian = new JButton("-");
 29 JButton bu_dengyu = new JButton("=");
 30 JButton bu_dian = new JButton(".");    //小数点，实现
 31 JButton bu_clean = new JButton("clean");//清除所有
 32 
 33 public mine() {//构造函数
 34     tf.setEditable(false);//不允许编辑
 35     
 36     bu0.setActionCommand("0");
 37     bu1.setActionCommand("1");
 38     bu2.setActionCommand("2");
 39     bu3.setActionCommand("3");
 40     bu4.setActionCommand("4");
 41     bu5.setActionCommand("5");
 42     bu6.setActionCommand("6");
 43     bu7.setActionCommand("7");
 44     bu8.setActionCommand("8");
 45     bu9.setActionCommand("9");
 46     bu_jia.setActionCommand("+");
 47     bu_jian.setActionCommand("-"); 
 48     bu_dengyu.setActionCommand("=");
 49     bu_dian.setActionCommand(".");
 50     bu_clean.setActionCommand("clean");
 51         
 52     //事件监听监听器，用this加进去 
 53     bu0.addActionListener(this);
 54     bu1.addActionListener(this);
 55     bu2.addActionListener(this);
 56     bu3.addActionListener(this);  
 57     bu4.addActionListener(this);
 58     bu5.addActionListener(this);
 59     bu6.addActionListener(this);
 60     bu7.addActionListener(this);
 61     bu8.addActionListener(this);
 62     bu9.addActionListener(this);
 63     bu_jia.addActionListener(this);
 64     bu_jian.addActionListener(this);
 65     bu_dengyu.addActionListener(this);
 66     bu_dian.addActionListener(this);
 67     bu_clean.addActionListener(this);
 68      
 69     tf.setPreferredSize(new Dimension(465, 40));
 70     //这儿是网格布局，这里就是按照顺序加入按钮
 71     pan2.add(bu1);
 72     pan2.add(bu2);
 73     pan2.add(bu3);
 74     pan2.add(bu4);
 75     pan2.add(bu5);
 76     pan2.add(bu6);    
 77         pan2.add(bu7);
 78     pan2.add(bu8);
 79     pan2.add(bu9);
 80     pan2.add(bu0);
 81     pan2.add(bu_dian);
 82     pan2.add(bu_dengyu); 
 83     pan2.add(bu_clean);
 84     pan2.add(bu_jia);
 85     pan2.add(bu_jian);
 86     this.setTitle("计算器"); 
 87 
 88     this.add(pan2, BorderLayout.CENTER);
 89     this.setSize(500, 350);
 90     this.setLocationRelativeTo(null); 
 91     this.setVisible(true);//显示框架
 92     this.setResizable(false);
 93     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //退出程序
 94     } 
 95 
 96 public void actionPerformed(ActionEvent e) 
 97 {  //操作处理
 98        if (e.getActionCommand().equals("1")) {opt(1);} //执行对应操作
 99 else if (e.getActionCommand().equals("2"))    {opt(2);} 
100 else if (e.getActionCommand().equals("3"))    {opt(3);} 
101 else if (e.getActionCommand().equals("4"))     {opt(4);}
102 else if (e.getActionCommand().equals("5"))     {opt(5);} 
103 else if (e.getActionCommand().equals("6"))     {opt(6);} 
104 else if (e.getActionCommand().equals("7"))    {opt(7);} 
105 else if (e.getActionCommand().equals("8"))     {opt(8);} 
106 else if (e.getActionCommand().equals("9"))    {opt(9);} 
107 else if (e.getActionCommand().equals("0"))     {opt(0);}
108 else if (e.getActionCommand().equals("+")) 
109         {
110         this.f = 1;tf.setText("");
111 fd = 0;this.t = 10.0;    } 
112 else if (e.getActionCommand().equals("-")) 
113         {
114                     this.f = 2;
115                     tf.setText("");
116                     fd = 0;
117                     this.t = 10.0;      } 
118 else if (e.getActionCommand().equals("=")) 
119         {calcu(this.a, this.b, this.f);    
120         this.a = 0;    
121         this.b = 0;
122         this.f = 0;
123         this.t = 10;
124         fd = 0;        } 
125 else if (e.getActionCommand().equals("clean")) 
126         {tf.setText("");    
127         this.a = 0;    
128         this.b = 0;    
129         this.f = 0;    
130         t = 10;    
131         fd = 0;
132     }         
133 else if (e.getActionCommand().equals("."))
134         {fd = 1;}
135      
136     }     
137 public void opt(int number) { 
138     //具体操作
139     if (this.f == 0) // the first number
140       {
141         if (fd == 0)// 没小数点
142           {this.a = this.a * 10 + number;
143           tf.setText(String.valueOf((int) this.a));
144               } 
145     else {// 有小数点
146             double dnumber;
147             dnumber = (double) number / t;
148             t = t * 10.0;
149             this.a += dnumber;
150             BigDecimal BB = new BigDecimal(this.a);
151             // 四舍五入取值
152             double dd = BB.setScale(8, BigDecimal.ROUND_HALF_DOWN).doubleValue();
153             tf.setText(String.valueOf(dd));
154             }         
155         } 
156     // this second number
157     else {    // 
158         t=10;
159             if (fd == 0)// 没小数点
160                  {this.b = this.b * 10 + number;    
161                  tf.setText(String.valueOf((int) this.b));    } 
162             else {
163                 double dnumber;    
164                 dnumber = (double) number / t;    
165                 t = t * 10.0;
166                 this.b += dnumber;
167                 BigDecimal BB = new BigDecimal(this.b);    
168                 double dd = BB.setScale(8, BigDecimal.ROUND_HALF_DOWN).doubleValue();
169                 tf.setText(String.valueOf(dd));    
170                 }
171         }    
172  }     
173 public void calcu(double a, double b, int f) {
174     double sum = 789;
175 
176 //用switch函数
177 switch (f) {    
178     case 0:  
179         //无操作直接按等于
180     case 1:  // 加        
181         sum = a + b;  break;    
182     case 2: // 减
183         sum = a - b;  break;
184         } 
185 
186 //对结果的一些操作  
187     double q1 = sum;    
188     int q2 = (int) q1;
189     double q3 = (double) q2;
190     if (q3 == sum)    
191         tf.setText(String.valueOf(q2));
192     else        
193         tf.setText(String.valueOf(sum));
194     this.a = sum;    
195     }     
196 
197 public static void main(String[] args) {
198     mine kk = new mine();
199     }
200 
201 }