为什么在paint方法里会执行2次?

[rao3324180]

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class Snake {

	public static void main(String[] args) {
		new Snasm().make();
	}
}

 class Snasm extends Frame{
	 
	public void make(){
		this.setLocation(200,200);
		this.setSize(200,200);
		this.addWindowListener(new WindowAdapter(){

			@Override
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
			
		});
		this.setVisible(true);
	}
	 
	public void paint(Graphics g){
		System.out.println("sd");
	}
}

为什么paint里面会打印2个"sd"

[stevenice85]

setsize的时候调用了paint吧

[神经研究所所长]

swing表示不清楚

[u011050058]

this.setLocation(200,200);方法调用了Component里的setLocation(200,200)，而这个方法一次进入回调用repaintParentIfNeeded（）方法， private void repaintParentIfNeeded(int oldX, int oldY, int oldWidth,int oldHeight) { if (parent != null && peer instanceof LightweightPeer && isShowing()) { // Have the parent redraw the area this component occupied. parent.repaint(oldX, oldY, oldWidth, oldHeight); // Have the parent redraw the area this component *now* occupies. repaint(); } } 这里重新打印了，repaint

[Inhibitory]

paint的执行次数是你没法控制的。

[森林西南角的飞鼠哥哥]

只打印一个ｓｄ，估计是你对窗口进行操作了，然后就继续打印了。