Help , why add another panel after listening to the keyboarduseless ?

  Games   java

I learn how to make the Snake game , when the control panel and without explanation panels, game panel buttons change according to the direction of the snake :

public class MainFrame {
 
 	public static void main(String[] args) {
 		// TODO 自动生成的方法存根
 		GamePanel gamePanel = new GamePanel();
 		OptionsPanel optionsPanel = new OptionsPanel();
 		JPanel infoPanel = new InfoPanel();
 		Snake snake = new Snake();
 		Food food = new Food();
 		Ground ground = new Ground();
 		Controller controller = new Controller(
 				snake, food, ground, gamePanel);
 		
 		JFrame jf = new JFrame();
 		jf.setTitle("HQS贪吃蛇");
 		
 		//不使用布局管理器！运用绝对布局！
 		jf.setLayout(null);
 		jf.setResizable(false);
 		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 		jf.setSize(Global.WIDTH * Global.CELL_SIZE + 20
 				, Global.HEIGHT * Global.CELL_SIZE + 250);
 		gamePanel.setSize(Global.WIDTH * Global.CELL_SIZE
 				, Global.HEIGHT * Global.CELL_SIZE);
 		gamePanel.setBorder(new EtchedBorder(EtchedBorder.LOWERED));
 		
 		//添加游戏面板
 		gamePanel.setBounds(5, 10, Global.WIDTH * Global.CELL_SIZE
 				, Global.HEIGHT * Global.CELL_SIZE);
 		jf.getContentPane().add(gamePanel);
 		
 		//添加控制面板
 		/*optionsPanel.setBounds(5, 415, 460, 200);
 		jf.getContentPane().add(optionsPanel);
 		
 		//添加说明面板
 		infoPanel.setBounds(470, 415, 235, 200);
 		jf.getContentPane().add(infoPanel);
 		*/
 		gamePanel.addKeyListener(controller);
 		snake.addSnakeListener(controller);
 		jf.addKeyListener(controller);
 		
 		jf.setVisible(true);
 		controller.newGame();
 		System.out.println("After running!");
 	}
 
 }After running!");
 	}
 
 }

but the control panel and the rear panel plus instructions , keyboard sniffers useless. Key smugglers did not respond !



This is the listener class :

public class Controller extends KeyAdapter implements SnakeListener {
 	
 	private Snake snake;
 	private Food food;
 	private Ground ground;
 	private GamePanel gamePanel;
 	
 	public Controller(Snake snake, Food food, Ground ground, GamePanel gamePanel) {
 		super();
 		this.snake = snake;
 		this.food = food;
 		this.ground = ground;
 		this.gamePanel = gamePanel;	
 	}
 	public void keyPressed(KeyEvent e) {
 		// TODO 自动生成的方法存根
 		super.keyPressed(e);
 		
 		System.out.println("key press~!");
 		//根据键盘按键，来改变方向
 		switch(e.getKeyCode()){
 		case KeyEvent.VK_UP:
 			System.out.println("UP");
 			snake.changeDirection(Snake.UP);
 			break;
 		case KeyEvent.VK_DOWN:
 			System.out.println("DOWN");
 			snake.changeDirection(Snake.DOWN);
 			break;
 		case KeyEvent.VK_LEFT:
 			System.out.println("LEFT");
 			snake.changeDirection(Snake.LEFT);
 			break;
 		case KeyEvent.VK_RIGHT:
 			System.out.println("RIGHT");
 			snake.changeDirection(Snake.RIGHT);
 			break;
 		default:
 				System.out.println("null");
 				break;
 		}
 	}
 	@Override
 	public void SnakeMove(Snake snake) {
 		// TODO 自动生成的方法存根
 		
 		if(food.isEatFood(snake)){
 			snake.eatFood();
 			food.newFood(ground.getPoint());
 		}
 		
 		if(ground.isSnakeEatRock(snake)){
 			snake.die(false);
 		}
 		
 		if(snake.isEatBody()){
 			snake.die(false);
 		}
 		gamePanel.dispaly(snake, food, ground);
 	}
 	
 	public void newGame(){
 		snake.start();
 		food.newFood(ground.getPoint());
 	}
 }

help it, this is where the problem is !
------ Solution ---------------------------------------- ----
JComponent and its subclasses have a grabFocus (), you try

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to set the display image components are always active.
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or listen on you most of the top-level container inside
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Thank However , JFrame not a top-level container it? "Jf.addKeyListener (controller);" should be added to the top of the container , right ?
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how to make components always active ?
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online help, nobody ah
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Thank you, has been resolved, because there was no let gamePanel component settings to get the focus method "this.setFocusable (true);".