顯示彈出框右鍵單擊JTree節點擺動

Question

我想顯示彈出框在右鍵單擊JTree節點只，而不是整個JTree組件。 當用戶右鍵單擊JTree節點時彈出框出現。如果他右擊JTree中的空白區域，則不應該出現。那麼爲什麼我只能檢測到JTree節點的鼠標事件。我在網上搜索過很多次，但找不到解決方案，請幫助我。

感謝。

Answer 1

這裏有一個簡單的方法：

public static void main (String[] args) 
{ 
    JFrame frame = new JFrame(); 

    final JTree tree = new JTree(); 
    tree.addMouseListener (new MouseAdapter() 
    { 
     public void mousePressed (MouseEvent e) 
     { 
      if (SwingUtilities.isRightMouseButton (e)) 
      { 
       TreePath path = tree.getPathForLocation (e.getX(), e.getY()); 
       Rectangle pathBounds = tree.getUI().getPathBounds (tree, path); 
       if (pathBounds != null && pathBounds.contains (e.getX(), e.getY())) 
       { 
        JPopupMenu menu = new JPopupMenu(); 
        menu.add (new JMenuItem ("Test")); 
        menu.show (tree, pathBounds.x, pathBounds.y + pathBounds.height); 
       } 
      } 
     } 
    }); 
    frame.add (tree); 


    frame.pack(); 
    frame.setLocationRelativeTo (null); 
    frame.setVisible (true); 
} 

Answer 2

只是因爲我最近偶然發現了這一點，我認爲這是比現有的答案更容易一點點：

public static void main(String[] args) { 
    JFrame frame = new JFrame(); 
    final JTree tree = new JTree(); 

    JPopupMenu menu = new JPopupMenu(); 
    menu.add(new JMenuItem("Test")); 
    tree.setComponentPopupMenu(menu); 
    frame.add(tree); 

    frame.pack(); 
    frame.setLocationRelativeTo(null); 
    frame.setVisible(true); 
}