java - 如何将 "for loop"中的变量值用于 mouseEntered？

Question

如何获取 panelResult[i].addMouseListener 中 mouseEntered 的“for 循环”中使用的“i”变量？谢谢!

buttonCategory[0].addMouseListener(new MouseAdapter() {

        @Override
        public void mouseClicked(MouseEvent e) {

            //hidden codes here...

            panelCategory.remove(scrollPane);
            panelCategory.add(scrollPane);
            panelArray.removeAll();
            panelResult = new JPanel[totalCount];
            int y = 0;
            for(int i = 0; i < panelResult.length; i++){

                panelResult[i] = new JPanel();
                panelResult[i].setLayout(null);
                panelResult[i].setBackground(new Color(27, 182, 32));
                panelResult[i].setBounds(0, y, 730, 200);
                panelArray.add(panelResult[i]);

                //hidden codes here...

                panelResult[i].add(labelArrayResult);

                panelResult[i].addMouseListener(new MouseAdapter() {

                    @Override
                    public void mouseEntered(MouseEvent e) {
                        panelResult[0].setBackground(Color.BLACK);
                        //if i change it to panelResult[i].setBackground(Color.BLACK); the "i" will be the error. i want to get the value of i from the panelResult[i].
                        revalidate();
                        repaint();
                    }

                });

            }

            revalidate();
            repaint();
        }

            revalidate();
            repaint();
        }

    });

我计划将它也用于 mouseClicked 和 mouseExited。它是一个结果列表，这就是为什么它全部被排列和循环的原因。

我得到的异常(exception)是:

Exception in thread "AWT-EventQueue-0" 
    java.lang.ArrayIndexOutOfBoundsException: 7
    at ph.edu.tip.cpedepartment.cpepds.ProjectDesignPage$1$1.mouseEntered(ProjectDesign‌​Page.java:233)

此外，面板的数量来自数据库的总数，这就是我需要使用索引的原因。再次感谢!

Answer 1

我相信您可以使用鼠标事件源来获取事件的来源:

                public void mouseEntered(MouseEvent e) {
                    ((JPanel)e.getSource()).setBackground(Color.BLACK);
                    //the index here is the error
                    revalidate();
                    repaint();
                }

如果这不起作用，我会尝试:

        for(int i = 0; i < panelResult.length; i++){

            //some hidden codes here...
            final JPanel panel = panelResult[i];
            panel.add(labelArrayResult);

            panel.addMouseListener(new MouseAdapter() {

                @Override
                public void mouseEntered(MouseEvent e) {
                    panel.setBackground(Color.BLACK);
                    //the index here is the error
                    revalidate();
                    repaint();
                }

            });

        }