Question

在我想要制作的游戏中，图像不会在我移动角色之前进行绘画。

这是我的代码：

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ForgottenMain extends JPanel implements KeyListener,MouseListener{
    /**
     * 
     */
    private static final int TIMER_DELAY = 35;
    private static final long serialVersionUID = -4926251405849574401L;
    public static BufferedImage attic,flashlight,player,killer;
    public static boolean up,down,left,right,inAttic;
    public static int px,py,kx,ky;
    public static int spawnLocation;
    public static JFrame frame = new JFrame("Forgotten");
    public static void main(String[] args){
        inAttic = true;
        px = 600;
        py = 400;
        frame.setSize(1200,800);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setResizable(false);
        frame.add(new ForgottenMain());
    }
    public ForgottenMain(){
        init();
    }
    public void init(){
        setSize(1200,800);
        setVisible(true);
        frame.addKeyListener(this);
        frame.addMouseListener(this);
        try{    
            player = ImageIO.read(new File("char.png"));
            flashlight = ImageIO.read(new File("flashlightimage.png"));
            attic = ImageIO.read(new File("attic.png"));
            killer = ImageIO.read(new File("killer.png"));
        } catch (Exception e){
            e.printStackTrace();
        }


        // Gameloop
          new javax.swing.Timer(TIMER_DELAY, new ActionListener() {
                 public void actionPerformed(ActionEvent e) {
                    gameLoop();
                 }
              }).start();   
    }
    public void paint(Graphics g){
        Graphics2D g2 = (Graphics2D) g;
        int fx = px - 1033;
        int fy = py - 635;
        kx = 500;
        ky = 500;
        // Removes the flickering of the images
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        // Resets the screen to make sure that it only shows the character once
        g2.clearRect(0, 0, 1200, 800);
        // Draws the background attic
        g2.drawImage(attic,0,0,this);
        // Draws the player
        g2.drawImage(player, px, py, this);
        // Draws the Serial Killer
        g2.drawImage(killer, kx, ky, this);
        // Draws the flashlight
        g2.drawImage(flashlight, fx, fy, this);
        System.out.println(px + " " + py);
    }
    public void gameLoop(){
        if(up == true && py > 88){
            py-=4;
            repaint();
        }
        if(down == true && py < 604){
            py+=4;
            repaint();
        }
        if(left == true && px > 80){
            px-=4;
            repaint();
        }
        if(right == true && px < 1028){
            px+=4;
            repaint();
        }
    }
    @Override
    public void mouseClicked(MouseEvent arg0) {
        System.out.println("MouseLocation: " + arg0.getX() + ", " + arg0.getY());
    }
    @Override
    public void mouseEntered(MouseEvent arg0) {

    }
    @Override
    public void mouseExited(MouseEvent arg0) {

    }
    @Override
    public void mousePressed(MouseEvent arg0) {

    }
    @Override
    public void mouseReleased(MouseEvent arg0) {

    }
    @Override
    public void keyPressed(KeyEvent e) {
        if(e.getKeyCode() == 87){
            up = true;
        }
        if(e.getKeyCode() == 83){
            down = true;
        }
        if(e.getKeyCode() == 65){
            left = true;
        }
        if(e.getKeyCode() == 68){
            right = true;
        }

    }
    @Override
    public void keyReleased(KeyEvent e) {
        if(e.getKeyCode() == 87){
            up = false;
        }
        if(e.getKeyCode() == 83){
            down = false;
        }
        if(e.getKeyCode() == 65){
            left = false;
        }
        if(e.getKeyCode() == 68){
            right = false;
        }

    }
    @Override
    public void keyTyped(KeyEvent e) {

    }
}

例如，在我的游戏中，您使用W，A，S和D键移动角色。当程序运行时，它显示一个空白屏幕，并且不显示应该绘制的所有内容，直到我按W，A，S或D.

如果我遗漏任何有用的信息，请告诉我。我想也许它是在图像初始化之前尝试绘制的，所以我在初始化它之后重新绘制它，它没有帮助。

Answer 1

问题是因为boolean值up，down，left或right都不是true，所以逻辑在gameLoop()无法呼叫repaint()！这可以通过从repaint()方法明确调用main(String[])来解决。

public static void main(String[] args) {
    inAttic = true;
    px = 600;
    py = 400;
    //frame.setSize(1200, 800);
    ForgottenMain fm = new ForgottenMain();
    frame.add(fm);
    frame.pack();

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocationRelativeTo(null);
    frame.setResizable(false);

    frame.setVisible(true);
    fm.repaint();
}

其他提示：

错误的方法：public void paint(Graphics g){ ..应为public void paintComponent(Graphics g){ super.paintComponent(g); ..（调用超级方法也很重要）。
frame.setSize(1200,800); .. setSize(1200,800);这是错误的，由于框架装饰，面板将小于1200 x 800，并且布局管理器通常会忽略大小超过首选大小。要解决这个问题：
1. @Override public Dimension getPreferredSize() { return new Dimension(1200,800); }（JPanel）。
2. 将面板添加到框架中。
3. 在添加组件并致电frame.pack();之后，在frame.setResizable(false);之前致电frame.setVisible(true); ..
player = ImageIO.read(new File("char.png"));应用程序资源在部署之前将成为嵌入式资源，因此立即开始访问它们是明智之举。必须通过URL而不是文件访问embedded-resource。有关如何形成网址，请参阅info. page for embedded resource。
if (e.getKeyCode() == 87) {不要使用“幻数”＆＃39;而是使用KeyEvent.VK_..。它不仅提供编译时检查，而且也是其他程序员的更好的文档。

在我搬东西之前不画画

1 个答案:

其他提示：