Bài giảng Lập trình Cơ sở dữ liệu – Java: Bài 3.2 - Nguyễn Hữu Thể

Bài giảng Lập trình cơ sở dữ liệu Java - Bài 3 tiếp tục cung cấp cho người học các kiến thức về Components. Nội dung chính được trình bày trong chương này gồm có: List JTable, JMenu, JOptionPane, JFileChooser. Mời các bạn cùng tham khảo nội dung chi tiết.

LẬP TRÌNH JAVA CSDL BÀI COMPONENTS Nguyễn Hữu Thể Nội dung  JList  JTable  JMenu  JOptionPane  JFileChooser JList Creating a Model There are three ways to create a list model: •DefaultListModel — everything is pretty much taken care of for you The examples in this page use DefaultListModel •AbstractListModel — you manage the data and invoke the "fire" methods For this approach, you must subclass AbstractListModel and implement the getSize and getElementAt methods inherited from the ListModel interface •ListModel — you manage everything JList Initializing a List list = new JList(data); //data has type Object[] list.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SE LECTION); list.setLayoutOrientation(JList.HORIZONTAL_WRAP); list.setVisibleRowCount(-1); JScrollPane listScroller = new JScrollPane(list); listScroller.setPreferredSize(new Dimension(250, 80)); JList  DefaultListModel  Methods: • addElement (Object e) • get (int index) • getSize () • getElementAt (int index) • remove (int index) • Elements() • removeAllElements () JList  Methods: – setModel (ListModel model), getModel () – getMaxSelectionIndex (), getMinSelectionIndex () – getSelectedIndex (), getSelectedIndices () – getSelectedValue (), getSelectedValues ()  Events: – valueChanged JTable JOptionPane JTable  DefaultTableModel – addColumn (Object obj) – addRow (Object obj) – getColumnCount () – getRowCount () – getValueAt (int row, int col) – setValueAt (Object obj, int row, int col) JTable  Methods: – setModel (TableModel tm) – getModel () – getValueAt (int row, int col) – getRowCount () – getColumnCount ()  Events: – mouseClicked 10 JOptionPane 16 JOptionPane 17 JFileChooser 18 JFileChooser 19 JFileChooser 20 JFileChooser 21 Swing Menu 22 Swing Menu import java.awt.*; import java.awt.event.*; import javax.swing.JMenu; import javax.swing.JMenuItem; import javax.swing.JCheckBoxMenuItem; import javax.swing.JRadioButtonMenuItem; import javax.swing.ButtonGroup; import javax.swing.JMenuBar; import javax.swing.KeyStroke; import javax.swing.ImageIcon; import javax.swing.JPanel; import javax.swing.JTextArea; import javax.swing.JScrollPane; import javax.swing.JFrame; 23 Swing Menu public class MenuLookDemo { JTextArea output; JScrollPane scrollPane; public JMenuBar createMenuBar() { JMenuBar menuBar; JMenu menu, submenu; JMenuItem menuItem; JRadioButtonMenuItem rbMenuItem; JCheckBoxMenuItem cbMenuItem; //Create the menu bar menuBar = new JMenuBar(); //Build the first menu menu = new JMenu("A Menu"); menu.setMnemonic(KeyEvent.VK_A); menu.getAccessibleContext().setAccessibleDescription( "The only menu in this program that has menu items"); menuBar.add(menu); 24 Swing Menu //a group of JMenuItems menuItem = new JMenuItem("A text-only menu item", KeyEvent.VK_T); //menuItem.setMnemonic(KeyEvent.VK_T); //used constructor instead menuItem.setAccelerator(KeyStroke.getKeyStroke( KeyEvent.VK_1, ActionEvent.ALT_MASK)); menuItem.getAccessibleContext().setAccessibleDescription( "This doesn't really anything"); menu.add(menuItem); ImageIcon icon = createImageIcon("images/middle.gif"); menuItem = new JMenuItem("Both text and icon", icon); menuItem.setMnemonic(KeyEvent.VK_B); menu.add(menuItem); menuItem = new JMenuItem(icon); menuItem.setMnemonic(KeyEvent.VK_D); menu.add(menuItem); 25 Swing Menu //a group of radio button menu items menu.addSeparator(); ButtonGroup group = new ButtonGroup(); rbMenuItem = new JRadioButtonMenuItem("A radio button menu item"); rbMenuItem.setSelected(true); rbMenuItem.setMnemonic(KeyEvent.VK_R); group.add(rbMenuItem); menu.add(rbMenuItem); rbMenuItem = new JRadioButtonMenuItem("Another one"); rbMenuItem.setMnemonic(KeyEvent.VK_O); group.add(rbMenuItem); menu.add(rbMenuItem); 26 //a group of check box menu items menu.addSeparator(); cbMenuItem = new JCheckBoxMenuItem("A check box menu item"); cbMenuItem.setMnemonic(KeyEvent.VK_C); menu.add(cbMenuItem); Swing Menu cbMenuItem = new JCheckBoxMenuItem("Another one"); cbMenuItem.setMnemonic(KeyEvent.VK_H); menu.add(cbMenuItem); //a submenu menu.addSeparator(); submenu = new JMenu("A submenu"); submenu.setMnemonic(KeyEvent.VK_S); menuItem = new JMenuItem("An item in the submenu"); menuItem.setAccelerator(KeyStroke.getKeyStroke( KeyEvent.VK_2, ActionEvent.ALT_MASK)); submenu.add(menuItem); menuItem = new JMenuItem("Another item"); submenu.add(menuItem); menu.add(submenu); 27 //Build second menu in the menu bar menu = new JMenu("Another Menu"); menu.setMnemonic(KeyEvent.VK_N); menu.getAccessibleContext().setAccessibleDescription( "This menu does nothing"); menuBar.add(menu); Swing Menu return menuBar; } public Container createContentPane() { //Create the content-pane-to-be JPanel contentPane = new JPanel(new BorderLayout()); contentPane.setOpaque(true); //Create a scrolled text area output = new JTextArea(5, 30); output.setEditable(false); scrollPane = new JScrollPane(output); //Add the text area to the content pane contentPane.add(scrollPane, BorderLayout.CENTER); return contentPane; } 28 /** Returns an ImageIcon, or null if the path was invalid */ protected static ImageIcon createImageIcon(String path) { java.net.URL imgURL = MenuLookDemo.class.getResource(path); if (imgURL != null) { return new ImageIcon(imgURL); } else { System.err.println("Couldn't find file: " + path); return null; } } Swing Menu /*** Create the GUI and show it For thread safety, * this method should be invoked from the * event-dispatching thread */ private static void createAndShowGUI() { //Create and set up the window JFrame frame = new JFrame("MenuLookDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane MenuLookDemo demo = new MenuLookDemo(); frame.setJMenuBar(demo.createMenuBar()); frame.setContentPane(demo.createContentPane()); //Display the window frame.setSize(450, 260); frame.setVisible(true); } 29 public static void main(String[] args) { Swing Menu //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } } 30 ... Events: – valueChanged JTable JOptionPane JTable  DefaultTableModel – addColumn (Object obj) – addRow (Object obj) – getColumnCount () – getRowCount () – getValueAt (int row, int col) – setValueAt... int row, int col) JTable  Methods: – setModel (TableModel tm) – getModel () – getValueAt (int row, int col) – getRowCount () – getColumnCount ()  Events: – mouseClicked 10 JTable package project;... removeAllElements () JList  Methods: – setModel (ListModel model), getModel () – getMaxSelectionIndex (), getMinSelectionIndex () – getSelectedIndex (), getSelectedIndices () – getSelectedValue (), getSelectedValues