swing JPopupMenu 单击按钮弹出 例子下载

swing JPopupMenu 单击按钮弹出 例子下载

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;

public class Main {
  public static void main(String[] argv) throws Exception {
    final JPopupMenu menu = new JPopupMenu();

    JMenuItem item = new JMenuItem("Item Label");
    
    menu.add(item);

    final JButton component = new JButton("button");

    component.addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        if (SwingUtilities.isLeftMouseButton(e)) {
          menu.show(e.getComponent(), Math.round(component.getAlignmentX()) - 15, 
            Math.round(component.getAlignmentY()) + 20);
        }
      }

      public void mouseReleased(MouseEvent evt) {
        if (evt.isPopupTrigger()) {
          //menu.show(evt.getComponent(), evt.getX(), evt.getY());
        }
      }
    });

    SwingUtilities.invokeLater(new Runnable() {

      public void run() {
        try {
          UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e) {
          e.printStackTrace();
        }
        JFrame frame = new JFrame("测试");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(new Dimension(800, 600));
        frame.setLocationRelativeTo(null);
        final JPanel mainPanel = new JPanel(new BorderLayout());

        JPanel topPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT, 0, 0));
        topPanel.add(component);

        mainPanel.add(topPanel, BorderLayout.NORTH);

        frame.getContentPane().setLayout(new BorderLayout());
        frame.getContentPane().add(mainPanel);

        frame.setVisible(true);
      }
    });
  }
}