java - 调整大小时，2D 对象被 JFrame 边缘遮挡

Question

我正在尝试用java swing制作一个2d游戏。当我调整 JFrame 的大小时，调整大小的边缘不透明，并且看不到 2d 对象。

JFrame 类代码:

public class GameFrame
extends JFrame 
{

public static JFrame G_FRAME = new JFrame();

private ArrayList<Integer> KL_DOWN;

private static GameDrawPlayer GD_PLAYER = new GameDrawPlayer();

public static int GF_WIDTH = G_FRAME.getWidth();

public static int GF_HEIGHT = G_FRAME.getHeight();

public static int H = 0;

public GameFrame()
{
    KL_DOWN = new ArrayList<Integer>();
    G_FRAME.setFocusable(true);
    G_FRAME.getContentPane().add(GD_PLAYER);
    GameKey keyListener = new GameKey(GD_PLAYER);
    G_FRAME.addKeyListener(keyListener);
    System.out.println(GF_WIDTH);
    CR_REPEAT.start();
}

public static void GL_FRAME(String TITLE, int WIDTH, int HEIGHT)
{
    javax.swing.SwingUtilities.invokeLater(new Runnable() 
    {
        public void run() 
        {
    G_FRAME.setLayout(new FlowLayout());
    G_FRAME.setTitle(TITLE);
    G_FRAME.setSize(WIDTH, HEIGHT);
    //G_FRAME.setResizable(false);
    G_FRAME.isResizable();
    G_FRAME.setMinimumSize(new Dimension(WIDTH, HEIGHT));
    G_FRAME.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    G_FRAME.pack();
    G_FRAME.setVisible(true);


        }
    }
  );

    try 
    {

        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    }
    catch (ClassNotFoundException
            | InstantiationException
            | IllegalAccessException
            | UnsupportedLookAndFeelException e1) 
    {
        e1.printStackTrace();
    }
}

private ActionListener LT_ACTION = new ActionListener()
{ 
    public void actionPerformed(ActionEvent e) 
    {   
        GF_WIDTH = G_FRAME.getWidth();

        GF_HEIGHT = G_FRAME.getHeight();
    }
}; 

private int speed = 1;

private Timer CR_REPEAT = new Timer(speed, LT_ACTION);

}

Graphics2D 类代码:

public class GameDrawPlayer
extends JComponent
{
   private static final int GP_W = 100;
   private static final int GP_H = 100;
   private static int GP_X = 0;
   private static int GP_Y = 0;
   private static GameClass GC = new GameClass();
   private static int GM_PIXEL = 1;

   private static Rectangle rect = new Rectangle(GP_X, GP_Y, GP_W, GP_H);
   private static BufferedImage G_BI;

   private static int GF_getWidth = GC.G_FRAME.G_FRAME.getWidth();
   private static int SD = (int) (GC.G_FRAME.G_FRAME.getWidth());

   public GameDrawPlayer()
   {
       try
          {
              G_BI = ImageIO.read(getClass().getResourceAsStream("/Images/Redox.png"));
          }
          catch (Exception e)
          {
              e.printStackTrace();
              System.out.println(e);
          }
       GF_REPEAT.start();
   }

   @Override
   public Dimension getPreferredSize() 
   {
      return new Dimension(GC.PREF_W, GC.PREF_H);
   }

   @Override
   protected void paintComponent(Graphics g) {
      super.paintComponent(g);

      Graphics2D g2 = (Graphics2D)g;

      g2.drawImage(G_BI, GP_X, GP_Y, GP_W, GP_H, null);
   }

   public void getImgLocation()
   {
       System.out.print(" <-> [" + GP_X + ", " + GP_Y + "]");
   }

   public void refresh(){repaint();};

   public void GPK_UP()
   {
       GP_Y = GP_Y - GM_PIXEL;
       repaint();
   }

   public void GPK_DOWN()
   {
       GP_Y = GP_Y + GM_PIXEL;
       repaint();
   }

   public void GPK_LEFT()
   {
       GP_X = GP_X - GM_PIXEL;
       repaint();
   }

   public void GPK_RIGHT()
   {
       GP_X = GP_X + GM_PIXEL;
       repaint();
   }

   private static int s = 0;

   public void GP_COLLISION()
   {   
       if (GP_X + GM_PIXEL > s - GP_W - (GP_W / 5) - 1)
           GP_X = s - GP_W - (GP_W / 5) - 1;
   }

   private ActionListener LT_ACTION = new ActionListener()
    { 
        public void actionPerformed(ActionEvent e) 
        {  
            s = GC.G_FRAME.GF_WIDTH;
        }
    }; 

    private int speed = 1;

    private Timer GF_REPEAT = new Timer(speed, LT_ACTION);

}

Answer 1

您将重写绘图 JPanel 上的 getPreferredSize，有效地将其大小设置为硬数字，然后将其添加到使用 **FlowLayout 的容器中。因此，如果 JPanel 的容器、JFrame 的 contentPane 增大并且绘图保持剪裁状态，则 JPanel 的大小不会增大。解决方案:出于此类目的，避免使用过于简单的布局(例如 FlowLayout)。为什么不使用 BorderLayout 来代替呢？

顺便说一句，您将需要学习和使用 Java naming conventions 。变量名应全部以小写字母开头，而类名应以大写字母开头。学习并遵循这一点将使我们更好地理解您的代码，并且将使您更好地理解其他人的代码。

除了第二点:你粗暴且不恰本地使用了 static 修饰符。我会避免使用它，除非您正在处理常量，或者您对它有明确的明确需要，并注意“编译器告诉我使用它”不算数，因为这仅意味着代码需要进行修复，以便编译器允许该变量保留实例变量。

旁白第三点:无论您认为 G_FRAME.isResizable(); 正在做什么，请理解它并没有这样做。这个调用除了返回一个 boolean 值之外什么也不做——一个你正在丢弃的 boolean 值。