图片按钮ImageButton

//按钮上放图片，图片按钮            JButton enterButton = new JButton("");            //由.png图片获得URL对象            URL url = getClass().getResource("enter.png");            //由URL获得ImageIcon对象            ImageIcon imageIcon = new ImageIcon(url);               enterButton.setBounds(0, 40,imageIcon.getIconWidth(), imageIcon.getIconHeight());            //设置ImageIcon                   enterButton.setIcon(imageIcon);            enterButton.setContentAreaFilled(false);    // 取消填充区域            enterButton.setBorder(null);                // 取消边框