画图时不能直接显示只有最小化后才显示

[sangqiesimajia]

代码下面放，百度说是重画的问题。可是移动窗口也不能显示

public class TankClient extends Frame{

	public static int WEIDTH=800;
	public static int HEIGHT=600;
 
	public List<Wall> walls=new ArrayList<Wall>();
         Graphics g=null;
         Image offScreenImage = null;
	
    class MouseMonitor extends MouseAdapter {
    	public void mouseClicked(MouseEvent e) {
    	    System.out.println("主页面的鼠标单击");
    		Point p=e.getPoint();
    		walls.add(new  Wall(p.x,p.y,Wall.wallStyle.stone,null));
    		
    	}	
    }
    
	public void lanchFrame(){
		
		this.setSize(WEIDTH, HEIGHT);
		this.setLocation(200, 50);
		setTitle("坦克大战");
		this.setBackground(Color.GREEN);
		
		this.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		new Thread(new PaintThread()).start();
		this.addMouseListener(new  MouseMonitor());
		
       
		this.setVisible(true); this.setResizable(false);
    }
	
	public void paint(Graphics g) {
		System.out.println("重画！");
		for(int i=0; i<walls.size(); i++) {
			Wall w = walls.get(i);
			w.draw(g);	
		}
	}
	
	
	public void update(Graphics g) {
		if(offScreenImage == null) {
			offScreenImage = this.createImage(WIDTH, HEIGHT);
		}
		Graphics gOffScreen = offScreenImage.getGraphics();
		Color c = gOffScreen.getColor();
		gOffScreen.setColor(Color.BLACK);
		gOffScreen.fillRect(0, 0, WIDTH,HEIGHT);
		gOffScreen.setColor(c);
		paint(gOffScreen);
		g.drawImage(offScreenImage, 0, 0, null);
	}
	
	private class PaintThread implements Runnable {

		public void run() {
			while(true) {
			    repaint();
				try {
					Thread.sleep(500);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}
	}
	
	public static void main(String[] args){
		new TankClient().lanchFrame();
	}
}

wall类的draw()

public void draw(Graphics g){
		System.out.println("draw");
		
		if(!this.live){
			tc.walls.remove(this);
			return ;
		}
		
		if(!init){
			System.out.println("initwall");
			init=true;
			for(int i=0;i<wallImage.length;i++){
				System.out.println("drawImage"+i);
				g.drawImage(wallImage[i], -100, -100, null);
			}
		}
		
		if(style==wallStyle.grass){
//			System.out.println("drawgrass"+locationX+locationY);
//			g.drawImage(wallImage[0], locationX, locationY, null);
			Color c = g.getColor();
			g.setColor(Color.DARK_GRAY);
			g.fillRect(locationX,locationY,50,50);
			g.setColor(c);
		}
		else if(style==wallStyle.stone){
//			System.out.println("drawstone"+locationX+locationY);
//			g.drawImage(wallImage[1], locationX, locationY, null);
			Color c = g.getColor();
			g.setColor(Color.DARK_GRAY);
			g.fillRect(locationX,locationY,50,50);
			g.setColor(c);
		}
	}

[shenhua]

如果出现需要最小化后才能出现内容的话都是“重画”那块的问题。有时候调用repaint()/getUI()/invalidate()/revalidate()的问题。你这点代码不好调试。

[sangqiesimajia]

[Quote=引用 1 楼 的回复:]

如果出现需要最小化后才能出现内容的话都是“重画”那块的问题。有时候调用repaint()/getUI()/invalidate()/revalidate()的问题。你这点代码不好调试。
[/Quote]
现在把继承改为JFrame就可以了，这不应该是重画的问题了吧，丫的现在背景色又改不了