title: how to hide background of JButton (which containt icon image)?
body: <p>I have this code to make a Jbutton with icon image ,and it works.But the problem is that the borders and background of button don't disappear.</p>
  
  <p>I want only the icon image is appear without borders &amp; background of button.</p>
  
  <p>I tried to set <code>setOpaque(false)</code>, but all of button disappeared!</p>
  
  <p>What is the wrong in my code ?</p>
  
  <pre><code>_button  = new JButton("Exit");
  _button.setHorizontalTextPosition(SwingConstants.CENTER);
  _button.setSize(200,130);
  //_button.setContentAreaFilled(false);
  _button.setBorderPainted(false);
  //_button.setOpaque(false);
  _button.setIgnoreRepaint(true);
  //_button.setFocusable(false);
  _button.setIcon(button_icon);
  _button.setBounds(200, 200,200, 170);
  _button.setRolloverEnabled(true);
  _button.setRolloverIcon(button_icon_hover);
  _button.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
  //_button.addActionListener(this);
  _button.setBackground(null);
  _button.setFocusable(true);
  _button.setFocusPainted(true);
  _button.setForeground(Color.WHITE);
  _button.setFont(new Font("Times New Roman",Font.BOLD,35));
  </code></pre>