这是我的代码。
private void caddMouseEntered(java.awt.event.MouseEvent evt) {
setRolloverIcon(Icon) (no need for the MouseListener)
cadd = new javax.swing.JButton();
cadd.setIcon(new javax.swing.ImageIcon(getClass().getResource("/rent/PNG/Add-Male.png")));
cadd.setBackground(Color.black);
cadd.setForeground(Color.white);
//v.setBackground(Color.black);
}