java的几个问题

期末要做项目了，几个问题问下大家1）java swing中按alt键来回切换菜单栏和其他板块（比如 windows的笔记本等等）2) java swing中菜单左上角的小图标怎么设置，怎么将.png、.gif等图片转成 image类3）java swing中 cardlayout具体怎么使用，希望能提供一小段代码4) 最后能讲下比较容易实现的加密算法的工作原理

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用javax swing有点烦，该显示的组件不能显示
cardlayout
我很少用这个哦..
书上有说啊..
一次只能显示一个组件..
1)设置窗口alt键监听事件，来控制切换可以实现
3）cardlayout布局，可以使用事件来切换它所管理的每个组件
4）最简单的加密解密就是使用异或一个整数来加密，解密也同样异或这个整数
切换你用个事件，按下alt，焦点会向下走一步。。你在JDK中查下有个image类，它里面有你需要的代码。。cardLayout是卡片布局了，怎么用就是比如说你有一叠扑克牌，使用卡片布局将他们装起来，当你点击一个按钮（“第一张牌”）时，它会显示第一张牌，当你点击（“后一张”）时，它会显示后面一张牌，比如A之后是2.。。加密算法简单的就是异或了，，我没用过加密算法，对于密码什么的，都是用password的。。
这个是以前写的。。关于卡片布局的。import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;public class CardLayoutManager extends JFrame implements ActionListener {
  /**
   * 设置左右两个面板,leftPanel存放五个按钮，rightPanel存放是个标签
   */
  private JPanel leftPanel, rightPanel;  /**
   * 设置右边面板的布局管理器为卡片布局
   */
  private CardLayout cl = new CardLayout();  private Container container = this.getContentPane();  public CardLayoutManager(String title) {
    super(title);
    this.setSize(500, 600);
    container.setLayout(new BorderLayout());
    container.add(buildLeftPanel(), BorderLayout.WEST);
    container.add(buildRightPanel());
  }  /**
   * 构造左边按钮面板
   *
   * @return
   */
  /*public JPanel buildLeftPanel() {
    if (leftPanel == null) {
      leftPanel = new JPanel();
      leftPanel.setLayout(new GridLayout(5, 1, 10, 0));

      leftPanel.add(buildBtn("第一张"));
      leftPanel.add(buildBtn("前一张"));
      leftPanel.add(buildBtn("后一张"));
      leftPanel.add(buildBtn("第3张"));
      leftPanel.add(buildBtn("最后一张"));
    }
    return leftPanel;
  }*/

  public Box buildLeftPanel(){
    Box box = new Box(BoxLayout.Y_AXIS);
    box.add(box.createHorizontalStrut(30));
    box.add(buildBtn("第一张"));
    box.add(box.createHorizontalStrut(30));
    box.add(buildBtn("前一张"));
    box.add(box.createHorizontalStrut(30));
    box.add(buildBtn("后一张"));
    box.add(box.createHorizontalStrut(30));
    box.add(buildBtn("第3张"));
    box.add(box.createHorizontalStrut(30));
    box.add(buildBtn("最后一张"));
    box.add(box.createHorizontalStrut(30));
    return box;
  }
  /**
   * 构造右边标签面板
   *
   * @return
   */
  public JPanel buildRightPanel() {
    if (rightPanel == null) {
      rightPanel = new JPanel();
      rightPanel.setBackground(Color.BLUE);
      rightPanel.setLayout(cl);
      rightPanel.add(buildJLabel("红桃尖", "icons/0.gif"), "1");
      rightPanel.add(buildJLabel("红桃贰", "icons/1.gif"), "2");
      rightPanel.add(buildJLabel("红桃叁", "icons/2.gif"), "3");
      rightPanel.add(buildJLabel("红桃肆", "icons/3.gif"), "4");
      rightPanel.add(buildJLabel("红桃伍", "icons/4.gif"), "5");
      rightPanel.add(buildJLabel("红桃六", "icons/5.gif"), "6");
      rightPanel.add(buildJLabel("红桃柒", "icons/6.gif"), "7");
      rightPanel.add(buildJLabel("红桃捌", "icons/7.gif"), "8");
      rightPanel.add(buildJLabel("红桃玖", "icons/8.gif"), "9");
      rightPanel.add(buildJLabel("红桃拾", "icons/9.gif"), "10");
      rightPanel.add(buildJLabel("小鬼", "icons/10.gif"), "11");
      rightPanel.add(buildJLabel("大鬼", "icons/11.gif"), "12");    }
    return rightPanel;
  }  private JLabel buildJLabel(String name, String icon) {
    //构造jlabel对象，设置字体居中显示
    JLabel lbl = new JLabel(name, JLabel.CENTER);
    //给标签对象加载图片
    lbl.setIcon(new ImageIcon(icon));
    //设置字体颜色
    lbl.setForeground(Color.RED);
    //设置标签上的字体风格为粗体，大小为30
    lbl.setFont(new Font(name, Font.ITALIC, 30));
    //设置标签上的文本居中
    lbl.setHorizontalTextPosition(SwingConstants.CENTER);
    //设置标签图片位于标签对象的底部
    lbl.setVerticalTextPosition(SwingConstants.BOTTOM);
    return lbl;
  }  private JButton buildBtn(String name) {
    JButton btn = new JButton(name);
    btn.addActionListener(this);
    return btn;
  }  public void actionPerformed(ActionEvent e) {
    String name = e.getActionCommand();
    if (name.equals("第一张")) {
      cl.first(rightPanel);
    } else if (name.equals("前一张")) {
      cl.previous(rightPanel);
    } else if (name.equals("后一张")) {
      cl.next(rightPanel);
    } else if (name.equals("第3张")) {
      cl.show(rightPanel, "3");
    } else if (name.equals("最后一张")) {
      cl.last(rightPanel);
    }
  }  /**
   * @param args
   */
  public static void main(String[] args) {
    new CardLayoutManager("卡片布局").setVisible(true);
  }}
关于CardLayout上边已经有代码了
我就不写了
上边是经典的翻牌
就是用CardLayout完成的关于alt+的问题我只实现ALT + H
其他的相信你能举一反三的
/**
1）java swing中按alt键来回切换菜单栏和其他板块（比如 windows的笔记本等等） 2) java swing中菜单左上角的小图标怎么设置，怎么将.png、.gif等图片转成 image类 3）java swing中 cardlayout具体怎么使用，希望能提供一小段代码 4) 最后能讲下比较容易实现的加密算法的工作原理
*/import java.awt.*;
import java.awt.event.*;
import javax.swing.*;public class AboutSwing {
public static void main(String[] args) {
new AboutSwingFrame();
}
}class AboutSwingFrame extends JFrame {
private Action saveAction;
private Action saveAsAction;
private JCheckBoxMenuItem readonlyItem;
private JPopupMenu popup;

private JPanel mainPanel = new JPanel();
private JPanel firstPanel = new JPanel();
private JPanel secondPanel = new JPanel();

private JLabel before = new JLabel("加密前的数字");
private JLabel after = new JLabel("加密后的数字");
JButton confuse = new JButton("加密");
JTextField beTF = new JTextField(10);
JTextField afTF = new JTextField(10);

public AboutSwingFrame() {
JMenu fileMenu = new JMenu("File");
JMenuItem newItem = fileMenu.add(new TestAction("New"));
JMenuItem openItem = fileMenu.add(new TestAction("Open"));
openItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_MASK));
fileMenu.addSeparator();

saveAction = new TestAction("Save");
JMenuItem saveItem = fileMenu.add(saveAction);
saveItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, InputEvent.CTRL_MASK));

saveAsAction = new TestAction("Save As");
JMenuItem saveAsItem = fileMenu.add(saveAsAction);
fileMenu.addSeparator();

fileMenu.add(new AbstractAction("Exit") {
public void actionPerformed(ActionEvent event) {
System.exit(0);
}
});

readonlyItem = new JCheckBoxMenuItem("Read-only");
readonlyItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
boolean saveOK = !readonlyItem.isSelected();
saveAction.setEnabled(saveOK);
saveAsAction.setEnabled(saveOK);
}
});

ButtonGroup group = new ButtonGroup();

JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert");
insertItem.setSelected(true);
JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype");

group.add(insertItem);
group.add(overtypeItem);

Action cutAction = new TestAction("Cut");
cutAction.putValue(Action.SMALL_ICON,new ImageIcon("cut.gif"));
Action copyAction = new TestAction("Copy");
copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));
Action pasteAction = new TestAction("Paste");
pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif"));

JMenu editMenu = new JMenu("Edit");
editMenu.add(cutAction);
editMenu.add(copyAction);
editMenu.add(pasteAction);

JMenu optionMenu = new JMenu("Options");

optionMenu.add(readonlyItem);
optionMenu.addSeparator();
optionMenu.add(insertItem);
optionMenu.add(overtypeItem);

editMenu.addSeparator();
editMenu.add(optionMenu);

JMenu helpMenu = new JMenu("Help");
helpMenu.setMnemonic('H');

JMenuItem indexItem = new JMenuItem("Index");
indexItem.setMnemonic('I');
helpMenu.add(indexItem);

Action aboutAction = new TestAction("About");
aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A'));
helpMenu.add(aboutAction);

JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);

menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(helpMenu);

popup = new JPopupMenu();
popup.add(cutAction);
popup.add(copyAction);
popup.add(pasteAction);

JPanel panel = new JPanel();
panel.setComponentPopupMenu(popup);
add(panel);

panel.addMouseListener(new MouseAdapter(){});

confuse.addActionListener(new ConfuseHandler());
firstPanel.setLayout(new GridLayout(3,1));
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
JPanel p3 = new JPanel();
p1.add(before);
p1.add(after);
p2.add(beTF);
p2.add(afTF);
p3.add(confuse);
firstPanel.add(p1);
firstPanel.add(p2);
firstPanel.add(p3);
mainPanel.add(firstPanel);
mainPanel.setLayout(new GridLayout(2,1));
add(mainPanel);

setSize(300,250);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}

private class ConfuseHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
String str1 = beTF.getText();
Integer temp =  Integer.parseInt(str1);
Integer result = temp*100/4+20;
String str2 = String.valueOf(result);
afTF.setText(str2);
}
}
}class TestAction extends AbstractAction {
public TestAction(String name) {
super(name);
}

public void actionPerformed(ActionEvent event) {
System.out.println(getValue(Action.NAME)+"selected.");
}
}
11楼的谢了，分不会忘的alt切换的问题还是不会啊，alt+‘char’的快键键那我知道，关系应该不大吧