jComponent中为什么调用repaint不起作用

[alexyang1990]

public class GridPanel extends JPanel {
	
	public PicComponent picComponent;	
	public GridPanel(){
		
	}
	
	public void paintPic() throws IOException{		
		setLayout(new GridLayout(CategoryPanel.Books.size()/3+1,3));
		for(int i = 0;i<CategoryPanel.Books.size();i++){
			String url = CategoryPanel.Books.get(i).getUrl();
			System.out.println(url);
			picComponent = new PicComponent(url);
			add(picComponent);
			picComponent.repaint();
		}
	}
}

class PicComponent extends JComponent{
	BufferedImage image = new BufferedImage(160, 160, BufferedImage.TYPE_3BYTE_BGR);

	public PicComponent(String url) throws IOException{			
		image = ImageIO.read(new File(url));
	}
	
	@Override
	protected void paintComponent(Graphics g) {
		super.paintComponent(g);
		g.drawImage(image, 0, 0, null);
	}
}

[alexyang1990]

现在只有改变窗口大小的时候才会重绘图像

[alexyang1990]

自己解决了，不是repaint的问题，就算调用paintimmediately进入了paint程序窗口还是不变化，应该已经绘制成功了，但是窗口没刷新，只需要调用validate来刷新一下组件就行了