Java中菜单的实现以及画实线与画虚线之间的自由转化

Posted 2021-01-31 进击的巨人

1、Java画线
  1 import java.awt.Color;
  2 import java.awt.Container;
  3 import java.awt.Graphics;
  4 import java.awt.Point;
  5 import java.awt.event.ActionEvent;
  6 import java.awt.event.ActionListener;
  7 
  8 import javax.swing.JFrame;
  9 import javax.swing.JMenu;
 10 import javax.swing.JMenuBar;
 11 import javax.swing.JMenuItem;
 12 import javax.swing.JPanel;
 13 
 14 class MyPanel extends JPanel {
 15     public static final int MODE_LINE = 1;
 16     public static final int MODE_POINT = 2;
 17     //
 18     private int drawMode = MODE_POINT;
 19 
 20     @Override
 21     protected void paintComponent(Graphics g) {
 22         // super.paintComponent(g);
 23 
 24         // g.setColor(Color.red);
 25         // g.fillOval(10, 10, 100, 80);
 26         drawSinAdapteSize(g);
 27 
 28         g.dispose();
 29     }
 30 
 31     // 自适应的绘图方法
 32     private void drawSinAdapteSize(Graphics g) {
 33         g.setColor(Color.red);
 34         int w = getWidth();
 35         int h = getHeight();
 36 
 37         int SCALE_X = (int) (w / (2 * Math.PI));
 38         int SCALE_Y = h / 2 - 2;
 39         int OFFSET = h / 2;
 40 
 41         Point start = new Point(0, OFFSET);
 42 
 43         for (int x = 1; x <= SCALE_X * 2 * Math.PI; x++) {
 44             int y = OFFSET - (int) (SCALE_Y * Math.sin(x * 1.0 / SCALE_X));
 45 
 46             // 根据属性，决定画线还是画点
 47             if (drawMode == MODE_POINT) {
 48                 g.fillOval(x - 1, y - 1, 2, 2);
 49             } else if (drawMode == MODE_LINE) {
 50                 g.drawLine(start.x, start.y, x, y);
 51 
 52                 start.x = x;
 53                 start.y = y;
 54             }
 55         }
 56     }
 57     
 58     public void setDrawMode(int mode) {
 59         this.drawMode = mode;
 60     }
 61 
 62     // 绘制制定大小的曲线
 63     private void drawSin(Graphics g) {
 64         g.setColor(Color.red);
 65         // y = 220 - 200 * sin(x/100)
 66         for (int x = 0; x <= 100 * 2 * Math.PI; x++) {
 67             int y = 220 - (int) (200 * Math.sin(x / 100.0));
 68 
 69             g.fillOval(x - 1, y - 1, 2, 2);
 70         }
 71     }
 72 }
 73 
 74 public class DrawFrame extends JFrame implements ActionListener {
 75     // 属性
 76     MyPanel panel = null;
 77 
 78     // 方法
 79     public DrawFrame() {
 80         this.setTitle("绘图");
 81         setSize(650, 500);
 82         setDefaultCloseOperation(EXIT_ON_CLOSE);
 83         setLocationRelativeTo(null);
 84 
 85         panel = new MyPanel();
 86         panel.setBackground(Color.LIGHT_GRAY);
 87 
 88         Container cp = getContentPane();
 89         cp.add(panel);
 90 
 91         // JMenuBar
 92         JMenuBar menuBar = new JMenuBar();
 93         // JMenu
 94         JMenu menu = new JMenu("Draw");
 95         // JMenuItem
 96         JMenuItem item = new JMenuItem("Line");
 97         menu.add(item);
 98         item.addActionListener(this);
 99 
100         item = new JMenuItem("Point");
101         menu.add(item);
102         item.addActionListener(this);
103         
104         menuBar.add(menu);
105         this.setJMenuBar(menuBar);
106     }
107 
108     public static void main(String[] args) {
109         JFrame frame = new DrawFrame();
110         frame.setVisible(true);
111     }
112 
113     @Override
114     public void actionPerformed(ActionEvent event) {
115         String cmd = event.getActionCommand();
116         if ("Line".equals(cmd)) {
117             panel.setDrawMode(MyPanel.MODE_LINE);
118         } else if ("Point".equals(cmd)) {
119             panel.setDrawMode(MyPanel.MODE_POINT);
120         }
121         panel.repaint();
122     }
123 
124 }

 2、Java菜单：

 1 import java.awt.event.ActionEvent;
 2 import java.awt.event.ActionListener;
 3 
 4 import javax.swing.JFrame;
 5 import javax.swing.JMenu;
 6 import javax.swing.JMenuBar;
 7 import javax.swing.JMenuItem;
 8 import javax.swing.JOptionPane;
 9 
10 public class MenuFrame extends JFrame implements ActionListener {
11     /**
12      * JMuneBar(菜单栏)中包含多项Jmenu(菜单),Jmenu下有多项JMenuItem(菜单项)
13      */
14     public MenuFrame() {
15         this.setTitle("MenuFrame");
16         this.setSize(600, 400);
17         setLocationRelativeTo(null);
18         setDefaultCloseOperation(EXIT_ON_CLOSE);
19         /**
20          * 由于失误，将所有的组件都用awt下的Menu,MenuItem,MenuBar来实现了，导致菜单中的汉字为乱码
21          */
22         JMenuBar menuBar=new JMenuBar();
23         JMenu menu=new JMenu("File");
24         JMenuItem menuItem=new JMenuItem("新建");
25         JMenuItem exit=new JMenuItem("退出");
26         exit.addActionListener(this);
27 
28         JMenuItem about=new JMenuItem("关于...");
29         about.addActionListener(this);
30         menu.add(menuItem);
31         menu.add(exit);
32         menu.add(about);
33         menuBar.add(menu);
34         
35         menuBar.add(new JMenu("Edit"));
36         
37         this.setJMenuBar(menuBar);//注意最后要将菜单栏加到MenuFrame组件中去，不然菜单不可见
38     }
39     public static void main(String[] args) {
40         JFrame frame=new MenuFrame();
41         frame.setVisible(true);
42     }
43     @Override
44     public void actionPerformed(ActionEvent e) {
45         String cmd=e.getActionCommand();
46         if(cmd.equals("Exit")) {
47             dispose();
48         }else if(cmd.equals("About")) {
49             JOptionPane.showMessageDialog(null, "菜单演示系统");
50         }
51     }
52 }