JFrame 将 22 像素偏移量 (java.awt.Insets) 添加到 Frame 顶部

This means the Bricks are off the top of the screen!

代码如下:

package BreakOut;

import javax.swing.*;

import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferStrategy;


public class Game extends JPanel implements KeyListener{

GameStateManager gsm = new GameStateManager();
BufferStrategy strategy;

public Game() {

    //add menu state to GameStateManager
    gsm.add(new MenuState(gsm));
    createFrame();


    while(true)
    {
        gsm.update();
        //repaint();
        render();
        try{
            Thread.sleep(10);
        }
        catch(InterruptedException e)
        {

        }
    }
}


public void createFrame()
{
    JFrame frame = new JFrame("Mini Tennis");
    frame.setLayout(new BorderLayout());
    this.setPreferredSize(new Dimension(400,400));
    frame.add(this);        
    frame.pack();       
    frame.setBackground(Color.BLACK);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    addKeyListener(this);
    this.setFocusable(true);
    frame.createBufferStrategy(2);
    strategy = frame.getBufferStrategy();
    frame.setVisible(true);
    System.out.println(frame.getInsets());
}


public void render()
{
    Graphics g = strategy.getDrawGraphics();
    super.paint(g);
    gsm.render(g);
    g.dispose();
    strategy.show();
}


public void keyPressed(KeyEvent k) {
    switch(gsm.getState())
    {
        case MAIN_MENU:
        if(k.getKeyCode()==KeyEvent.VK_ENTER)
        {
            //add the PlayState to the Stack and update enum value
            gsm.add(new PlayState(gsm, this));
        }
        break;
        case PLAYING:
            if(k.getKeyCode()==KeyEvent.VK_P)
            {
                //add the PlayState to the Stack and update enum value
                gsm.add(new PauseState(gsm));
            }
            break;
        case PAUSE:
            if(k.getKeyCode()==KeyEvent.VK_P)
            {                   
                gsm.pop();
            }
            break;
        case GAME_OVER:
            if(k.getKeyCode()==KeyEvent.VK_ENTER)
            {                   
                gsm.pop();
            }
            break;
    }
    //send input to GameStateManager
    gsm.keyPressed(k.getKeyCode()); 
}

public void keyReleased(KeyEvent k) {
    gsm.keyReleased(k.getKeyCode());        
}

public void keyTyped(KeyEvent k) {
    gsm.keyTyped(k.getKeyCode());   
}


public static void main(String[] args) {
    new Game();

}

}

当我输出 System.out.println(frame.getInsets());我明白了

java.awt.Insets[top=22,left=0,bottom=0,right=0]