弹出菜单

Java弹出菜单示例

最新推荐文章于 2024-05-21 17:25:53 发布

最新推荐文章于 2024-05-21 17:25:53 发布 · 143 阅读

文章标签：

#UP

本文介绍了一个使用Java Swing创建弹出菜单的例子。通过构造弹出菜单并为其添加菜单项，然后为这些菜单项添加监听器来响应用户的交互。文章还展示了如何通过MouseListener监听鼠标事件并在适当的时候显示弹出菜单。

//...where instance variables are declared:
JPopupMenu popup;

    //...where the GUI is constructed:
    //Create the popup menu.
    popup = new JPopupMenu();
    menuItem = new JMenuItem("A popup menu item");
    menuItem.addActionListener(this);
    popup.add(menuItem);
    menuItem = new JMenuItem("Another popup menu item");
    menuItem.addActionListener(this);
    popup.add(menuItem);

    //Add listener to components that can bring up popup menus.
    MouseListener popupListener = new PopupListener();
    output.addMouseListener(popupListener);
    menuBar.addMouseListener(popupListener);
...
class PopupListener extends MouseAdapter {
    public void mousePressed(MouseEvent e) {
        maybeShowPopup(e);
    }

    public void mouseReleased(MouseEvent e) {
        maybeShowPopup(e);
    }

    private void maybeShowPopup(MouseEvent e) {
        if (e.isPopupTrigger()) {
            popup.show(e.getComponent(),
                       e.getX(), e.getY());
        }
    }
}