我试图让我JMenuBar
模拟 Firefox 和 iTunes 的菜单栏的行为。行为:菜单栏最初是隐藏的。但是,当您按下 时Alt
,会出现菜单栏(选中第一个项目),当您没有选择菜单项时,菜单栏会消失。JMenuBar
我的想法是ChangeListener
在其SelectionModel
.
但是,附加的SSCCE的行为并不如预期。当框架加载时,JMenuBar
是不可见的。当您按下Alt
时,将出现菜单栏并选择第一个菜单(感谢WindowsLookAndFeel
)。但是,随后的每一次Alt
按下都会触发 no ChangeEvents
。我想不通为什么...
有谁有光可以散光吗?
public class MenuBarTest extends javax.swing.JFrame {
public MenuBarTest() {
initComponents();
jMenuBar1.setVisible(false);
jMenuBar1.getSelectionModel().addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
System.out.println(e.toString());
jMenuBar1.setVisible(jMenuBar1.isSelected());
System.out.println(jMenuBar1.isSelected());
System.out.println(jMenuBar1.getSelectionModel().isSelected());
}
});
}
private void initComponents() {
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
jMenuItem1 = new javax.swing.JMenuItem();
jMenu2 = new javax.swing.JMenu();
jMenuItem2 = new javax.swing.JMenuItem();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jMenu1.setText("File");
jMenuItem1.setText("jMenuItem1");
jMenu1.add(jMenuItem1);
jMenuBar1.add(jMenu1);
jMenu2.setText("Edit");
jMenuItem2.setText("jMenuItem2");
jMenu2.add(jMenuItem2);
jMenuBar1.add(jMenu2);
setJMenuBar(jMenuBar1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE));
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 279, Short.MAX_VALUE));
pack();
}
public static void main(String args[]) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewClass().setVisible(true);
}
});
}
private javax.swing.JMenu jMenu1;
private javax.swing.JMenu jMenu2;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JMenuItem jMenuItem1;
private javax.swing.JMenuItem jMenuItem2;
}