1 import java.awt.BorderLayout;
  2 import java.awt.EventQueue;
  3 import java.awt.event.ActionEvent;
  4 import java.awt.event.ActionListener;
  5 import java.io.File;
  6 import java.io.IOException;
  7
  8 import javax.imageio.ImageIO;
  9 import javax.swing.ImageIcon;
 10 import javax.swing.JButton;
 11 import javax.swing.JFileChooser;
 12 import javax.swing.JFrame;
 13 import javax.swing.JLabel;
 14 import javax.swing.JMenu;
 15 import javax.swing.JMenuBar;
 16 import javax.swing.JMenuItem;
 17 import javax.swing.JOptionPane;
 18 import javax.swing.JToolBar;
 19
 20 public class TestMenu extends JFrame {
 21     private JToolBar toolBar = new JToolBar();
 22     private JButton up = new JButton("up");
 23     private JButton down = new JButton("down");
 24     private JLabel label;
 25     private JFileChooser chooser;
 26     private static String[] currentPath = new String[10000];// 最多一万张图片
 27     private static int dirPhotoCount = 0;
 28     private static boolean flag = false; //user yes or not open dir
 29
 30     public static void getFileNameToFullPhotoArray(String dirPath) {
 31         String path = dirPath;
 32         File f = new File(path);
 33         if (!f.exists()) {
 34             System.out.println(path + " not exists");
 35             return;
 36         }
 37         int cut = 0;
 38         File fa[] = f.listFiles();
 39         for (int i = 0; i < fa.length; i++) {
 40             File fs = fa[i];
 41             try {
 42                 if (ImageIO.read(fs) != null) { // Yes or not photo style file.
 43                     currentPath[cut++] = dirPath + "\\" + fs.getName();
 44                 }
 45             } catch (IOException ex) {
 46
 47             }
 48         }
 49         dirPhotoCount = cut;
 50     }
 51
 52     public TestMenu() {
 53         super();
 54         setTitle("PHOTO viewer");
 55         getContentPane().add(toolBar, BorderLayout.NORTH);
 56         label = new JLabel();
 57         this.chooser = new JFileChooser();// java provide file selected
 58         chooser.setCurrentDirectory(new File("."));// view path
 59
 60         JMenuBar jmb = new JMenuBar();
 61         setJMenuBar(jmb);
 62         JMenu fileMenu = new JMenu("File");
 63         JMenuItem jmiExit = new JMenuItem("Exit");
 64         JMenuItem jmiOpen = new JMenuItem("Open");
 65         jmb.add(fileMenu);
 66         toolBar.add(up);
 67         toolBar.add(down);
 68         getContentPane().add(toolBar, BorderLayout.NORTH);
 69         add(label);
 70         jmb.add(fileMenu);
 71         fileMenu.add(jmiOpen);
 72         fileMenu.add(jmiExit);
 73
 74         up.addActionListener(new ActionListener() {
 75             public void actionPerformed(ActionEvent e) {
 76
 77                 if (flag) {
 78                     String dir = chooser.getSelectedFile().getParent();
 79                     getFileNameToFullPhotoArray(dir);// current dir build photo array
 80                     String currentImage = label.getIcon().toString();
 81                     for (int i = 0; i < dirPhotoCount; i++) {
 82                         if (currentPath[i].equals(currentImage)) {
 83                             label.setIcon(new ImageIcon(currentPath[i == 0 ? dirPhotoCount - 1 : i - 1]));
 84                             break;
 85                         }
 86                     }
 87                 } else {
 88                     JOptionPane.showMessageDialog(null, "当前无图片，请选择正确文件", "打开失败", JOptionPane.ERROR_MESSAGE);
 89
 90                 }
 91             }
 92
 93         });
 94         down.addActionListener(new ActionListener() {
 95             public void actionPerformed(ActionEvent e) {
 96
 97                 if (flag) {
 98                     String dir = chooser.getSelectedFile().getParent();
 99                     getFileNameToFullPhotoArray(dir);// 对当前目录建立图片数组
100                     String currentImage = label.getIcon().toString();
101                     for (int i = 0; i < dirPhotoCount; i++) {
102                         if (currentPath[i].equals(currentImage)) {
103                             label.setIcon(new ImageIcon(currentPath[i == dirPhotoCount - 1 ? 0 : i + 1]));
104                             break;
105                         }
106                     }
107                 } else {
108
109                     JOptionPane.showMessageDialog(null, "当前无图片，请选择正确文件", "打开失败", JOptionPane.ERROR_MESSAGE);
110
111                 }
112             }
113
114         });
115
116         jmiOpen.addActionListener(new ActionListener() {
117             public void actionPerformed(ActionEvent e) {
118                 int result = chooser.showOpenDialog(null);
119                 if (result == JFileChooser.APPROVE_OPTION) {
120                     try {
121                         if (ImageIO.read(chooser.getSelectedFile()) != null) { // 判断是否是图片文件
122                             flag = true;
123                             String name = chooser.getSelectedFile().getPath();
124                             label.setIcon(new ImageIcon(name));
125                         } else {
126                             JOptionPane.showMessageDialog(null, "请选择正确文件", "打开失败", JOptionPane.ERROR_MESSAGE);
127                         }
128                     } catch (IOException ex) {
129
130                     }
131
132                 }
133             }
134         });
135
136         jmiExit.addActionListener(new ActionListener() {
137             public void actionPerformed(ActionEvent e) {
138                 System.exit(0);
139             }
140         });
141     }
142
143     public static void main(String args[]) {
144         EventQueue.invokeLater(new Runnable() {// using Runnable anonymous
145                                                 // object
146             public void run() {
147                 JFrame frame = new TestMenu();
148                 frame.setSize(500, 400);
149                 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
150                 frame.setVisible(true);
151
152             }
153
154         });
155
156     }
157
158 }