refresh JPanel & print Image in JPanel

//刷新JPanel
public void refresh() {
		contentPanel.validate();
		contentPanel.revalidate();
		contentPanel.updateUI();
               contentPanel.repaint();
	}

 

 

JPanel里面画背景图片:

@Override
	protected void paintComponent(Graphics g){
		paintBackLeftImg(g);
		paintBackCentertImg(g);
		this.setOpaque(false);//!!!
	}

	private void paintBackCentertImg(Graphics g) {
		ImageIcon bg = new ImageIcon("pic/yct/backYCTWaitCard.jpg");
		g.drawImage(bg.getImage(), getBackgroudLeft().getWidth(), 0,
				Color.green, null);
	}

 

 

sun forums :

cPane=new JPanel() {
  public void paintComponent(Graphics g)
  {
    ImageIcon icon=new ImageIcon(ClassLoader.getSystemResource("test.jpg"));
    Rectangle rect=g.getClipBounds();
    g.fillRect(rect.x, rect.y, rect.width, rect.height);
    g.drawImage(icon.getImage(), 0, 0, Color.green, null);
  }
};
cPane.setOpaque(false);