在菜单中动态添加menuitem而不关闭菜单

Question

我想在JMenuItem不关闭的情况下添加JMenu.菜单包含a JTextField,当我在文本字段中输入时,它添加了一个菜单项.我的问题是添加菜单项的大小太小.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JMenuItem;
import javax.swing.JTextField;

public class NewJFrame extends javax.swing.JFrame {

public NewJFrame() {
    initComponents();
    this.jMenu1.addSeparator();
    final JTextField jTextField = new JTextField("Menu 1",20);
    this.jMenu1.add(jTextField);   

    jTextField.addActionListener(new ActionListener( ){
        @Override
        public void actionPerformed(ActionEvent e) { 
           final JMenuItem jMenuItem = new JMenuItem(jTextField.getText());
            jMenu1.add(jMenuItem);
             jMenuItem.repaint();
             jMenuItem.revalidate();

        }    
    });

}

@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {

    jMenuBar1 = new javax.swing.JMenuBar();
    jMenu1 = new javax.swing.JMenu();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jMenu1.setText("File");
    jMenuBar1.add(jMenu1);

    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();
}// </editor-fold>//GEN-END:initComponents

public static void main(String args[]) {
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new NewJFrame().setVisible(true);
        }
    });
}


// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JMenu jMenu1;
private javax.swing.JMenuBar jMenuBar1;
// End of variables declaration//GEN-END:variables
}

当我按Enter键时,菜单添加一个菜单项,但其宽度太小.

我该如何解决？

Answer 1

你必须更新jMenu1的popupMenu,调用:

jMenu1.getPopupMenu().pack();

代替

jMenuItem.repaint();
jMenuItem.revalidate();

Answer 2

不要重新绘制它，而是关闭菜单并重新打开它。刚刚尝试了一下，效果很好，就像当场重新喷漆一样快。

jMenu1.add(jMenuItem);
//jMenuItem.repaint();
//jMenuItem.revalidate();
MenuElement[] selectionPath = MenuSelectionManager.defaultManager().getSelectedPath();
MenuSelectionManager.defaultManager().clearSelectedPath();
MenuSelectionManager.defaultManager().setSelectedPath(selectionPath);