java - 在我的代码中实现 mouseClicked

Question

这是我第一次用 Java 编写游戏。我正在制作一款角色扮演游戏。我已经成功地使用 KeyListener 函数用箭头键移动我的角色。但是，当在窗口中单击鼠标时，我一直试图将角色移向鼠标。我已经发现它可以使用 mouseClicked 函数来完成，但我似乎无法在我的代码中实现它。我一直在试图理解布局它的正确方法，但互联网上所有不同的代码让我越来越困惑。我正在上传我的玩家类，其中包含我在 mouseAdapter 上的小代码。任何有关实现的帮助将不胜感激。

import java.awt.Graphics;
import java.awt.event.KeyListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionAdapter;
import java.awt.event.MouseAdapter;



public class Player implements KeyListener {

private int x,y;
private SpriteSheet ss;
private boolean up = false, down = false, left= false, right = false;
public boolean mouseActive = false;  // mouse

public Point mouse;  // mouse

private final int SPEED = 3;


public Player( int x, int y, SpriteSheet ss) {
this.x = x;
this.y = y;
this.ss = ss;
}

public void tick() {
if(up) {
  y-=SPEED;
}

if (down) {
  y+=SPEED;
}

if (left){
  x-=SPEED;
}

if (right) {
  x+=SPEED;
}
}

public void render( Graphics g) {
g.drawImage(ss.crop(0,0,16,16), x, y, 16* Game.SCALE, 16* Game.SCALE, null);
}

public void keyPressed(KeyEvent e) {
 if (e.getKeyCode() == KeyEvent.VK_UP) {
  up = true;

}
if (e.getKeyCode() == KeyEvent.VK_DOWN) {
  down = true;
}

if (e.getKeyCode() == KeyEvent.VK_LEFT) {
  left = true;
}

if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
  right = true;
}

if (e.getKeyCode() == KeyEvent.VK_M) {     // mouse
  mouseActive = true;
}

}

public void keyReleased(KeyEvent e) {

 if (e.getKeyCode() == KeyEvent.VK_UP) {
  up = false;
}
if (e.getKeyCode() == KeyEvent.VK_DOWN) {
  down = false;
}

if (e.getKeyCode() == KeyEvent.VK_LEFT) {
  left = false;
}

if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
  right = false;
}

if (e.getKeyCode() == KeyEvent.VK_M) {
  mouseActive = false;
}

}

 //  this is where I have been trying to add mouseClicked function to my code



 addMouseListener( new MouseAdapter() {

 public void mouseClicked(MouseEvent e) {
  mouse = new Point(e.getX(), e.getY() - 25);

  if(e.getButton() == MouseEvent.BUTTON1 && !mouseActive) {
    x = mouse.x;
    y = mouse.y;
  }
  }
  });



}

编译错误:发现 5 个错误:

文件:/Users/welcome/Documents/Player.java [行:11]错误:/Users/welcome/Documents/Player.java:11:Player 不是抽象的，并且不会重写 java.awt.event.KeyListener 中的抽象方法 keyTyped(java.awt.event.KeyEvent)

文件:/Users/welcome/Documents/Player.java [行:18]错误:/Users/welcome/Documents/Player.java:18:找不到符号符号:类点位置:玩家类

文件:/Users/welcome/Documents/Player.java [行:112]错误:/Users/welcome/Documents/Player.java:112:找不到符号符号:类MouseEvent位置:玩家类

文件:/Users/welcome/Documents/Player.java [行:113]错误:/Users/welcome/Documents/Player.java:113:找不到符号符号:类点位置:玩家类

文件:/Users/welcome/Documents/Player.java [行:115]错误:/Users/welcome/Documents/Player.java:115:找不到符号符号:变量MouseEvent位置:玩家类

Answer 1

这是概念证明。这个想法是角色将始终尝试向给定点移动(在本例中为目标)。

键盘控制元素的设计目的是在按下键盘控制元素时将目标移动到距当前玩家位置指定的距离。

鼠标控制元件简单地将目标移动到鼠标单击的位置。

主机只是尝试将角色驱动到该点。

在此示例中，键盘操作会覆盖鼠标操作

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class MoveMe {

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

    public MoveMe() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new Surface());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public enum KeyControl {

        UP, DOWN, LEFT, RIGHT
    }

    public class Surface extends JPanel {

        private Character character;
        private Point target;

        private int xDelta = 2;
        private int yDelta = 2;

        private Set<KeyControl> keyControls;

        public Surface() {
            keyControls = new HashSet<>(4);
            character = new Character(new Rectangle(95, 95, 10, 10));
            Timer timer = new Timer(40, new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    processKeyCommands();
                    if (target != null) {
                        Rectangle bounds = character.getBounds();
                        Point cp = new Point(bounds.getLocation());
                        cp.x += bounds.width / 2;
                        cp.y += bounds.height / 2;

                        if (!cp.equals(target)) {
                            if (cp.x != target.x) {
                                if (target.x < cp.x) {
                                    cp.x -= xDelta;
                                    if (cp.x < target.x) {
                                        cp.x = target.x;
                                    }
                                } else {
                                    cp.x += xDelta;
                                    if (cp.x > target.x) {
                                        cp.x = target.x;
                                    }
                                }
                            }
                            if (target.y != cp.y) {
                                if (target.y < cp.y) {
                                    cp.y -= yDelta;
                                    if (cp.y < target.y) {
                                        cp.y = target.y;
                                    }
                                } else {
                                    cp.y += yDelta;
                                    if (cp.y > target.y) {
                                        cp.y = target.y;
                                    }
                                }
                            }

                            bounds.x = cp.x - bounds.width / 2;
                            bounds.y = cp.y - bounds.height / 2;

                            if (bounds.x < 0) {
                                bounds.x = 0;
                            } else if (bounds.x + bounds.width > getWidth()) {
                                bounds.x = getWidth() - bounds.width;
                            }
                            if (bounds.y < 0) {
                                bounds.y = 0;
                            } else if (bounds.y + bounds.height > getHeight()) {
                                bounds.y = getHeight() - bounds.height;
                            }
                        } else {
                            target = null;
                        }
                    }
                    repaint();
                }

            });
            timer.start();

            addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    target = e.getPoint();
                }
            });

            InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, false), "pressUp");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, false), "pressDown");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, false), "pressLeft");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, false), "pressRight");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, true), "releaseUp");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, true), "releaseDown");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, true), "releaseLeft");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, true), "releaseRight");

            ActionMap am = getActionMap();
            am.put("pressUp", new KeyStateAction(keyControls, KeyControl.UP, true));
            am.put("pressDown", new KeyStateAction(keyControls, KeyControl.DOWN, true));
            am.put("pressLeft", new KeyStateAction(keyControls, KeyControl.LEFT, true));
            am.put("pressRight", new KeyStateAction(keyControls, KeyControl.RIGHT, true));
            am.put("releaseUp", new KeyStateAction(keyControls, KeyControl.UP, false));
            am.put("releaseDown", new KeyStateAction(keyControls, KeyControl.DOWN, false));
            am.put("releaseLeft", new KeyStateAction(keyControls, KeyControl.LEFT, false));
            am.put("releaseRight", new KeyStateAction(keyControls, KeyControl.RIGHT, false));
        }

        protected Point createTargetBasedOnCharacter() {
            target = new Point();
            Rectangle bounds = character.getBounds();
            target.x = bounds.x + bounds.width / 2;
            target.y = bounds.y + bounds.height / 2;
            return target;
        }

        protected void processKeyCommands() {
            if (keyControls.contains(KeyControl.UP)) {
                Point target = createTargetBasedOnCharacter();
                target.y -= xDelta;
            } else if (keyControls.contains(KeyControl.DOWN)) {
                Point target = createTargetBasedOnCharacter();
                target.y += xDelta;
            }
            if (keyControls.contains(KeyControl.LEFT)) {
                Point target = createTargetBasedOnCharacter();
                target.x -= xDelta;
            } else if (keyControls.contains(KeyControl.RIGHT)) {
                Point target = createTargetBasedOnCharacter();
                target.x += xDelta;
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            if (target != null) {
                g2d.setColor(Color.RED);
                g2d.fillOval(target.x - 5, target.y - 5, 10, 10);
            }
            character.render(g2d);
            g2d.dispose();
        }
    }

    public class Character {

        private Rectangle bounds;

        public Character(Rectangle bounds) {
            this.bounds = bounds;
        }

        public Rectangle getBounds() {
            return bounds;
        }

        public void render(Graphics2D g) {
            g.setColor(Color.BLUE);
            g.fill(getBounds());
        }

    }

    public class KeyStateAction extends AbstractAction {

        private final Set<KeyControl> keyControls;
        private final KeyControl keyControl;
        private final boolean pressed;

        private KeyStateAction(Set<KeyControl> keyControls, KeyControl keyControl, boolean pressed) {
            this.keyControls = keyControls;
            this.keyControl = keyControl;
            this.pressed = pressed;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            if (pressed) {
                keyControls.add(keyControl);
            } else {
                keyControls.remove(keyControl);
            }
        }
    }

}

此示例使用 key bindings API这可以更好地控制触发关键事件所需的焦点级别。

我还将实体(Character)与控件分离。这是键盘和鼠标控件，由 Surface 管理，恕我直言，玩家实体应该不知道。这集中了控制，意味着角色可以通过您想要添加的任何输入来移动......