如何在此代码中调整重影移动的速度？所需的代码已经在那里，我只需要更改值？还是我需要添加任何东西？我对编码还很陌生，因此请尝试以尽可能简单的形式进行编码。谢谢。
package basicgame;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class JavaGame extends JPanel {
int x, y;
// private Image dbImage;
//private Graphics dbg;
Image ghost;
Image bg;
public class AL extends KeyAdapter {
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == e.VK_LEFT) {
if (x <= 8)
x = 8;
else
x += -5;
}
if (keyCode == e.VK_RIGHT) {
if (x >= 435)
x = 435;
else
x += +5;
}
if (keyCode == e.VK_UP) {
if (y <= 18)
y = 18;
else
y += -5;
}
if (keyCode == e.VK_DOWN) {
if (y >= 325)
y = 325;
else
y += +5;
}
}
public void keyReleased(KeyEvent e) {
}
}
public JavaGame() throws Exception {
// Load images
ghost = ImageIO.read(new File("ghost.gif"));
bg = ImageIO.read(new File("myBkg.PNG"));
setFocusable(true);
// Game properties
addKeyListener(new AL());
x = 10;
y = 10;
ActionListener al = new ActionListener() {
public void actionPerformed(ActionEvent ae) {
repaint();
}
};
Timer timer = new Timer(10,al);
timer.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
// here, you have a 'drawimage' command for each object you're moving
// if you have 2 players, you have another drawImage for that one
// if you have a bullet, you have another for it. You have to keep
//track of each object's x,y coordinates and then draw the image at that position.
//you'll need some collision detection in there to see if bullets/players are
//in the same position and then act accordingly.
g.drawImage(bg, 0, 0, null);
g.drawImage(ghost, x, y, this);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
JFrame f = new JFrame("Java Game");
f.setSize(500, 500);
f.setResizable(false);
f.setVisible(true);
f.setBackground(Color.GRAY);
f.setContentPane(new JavaGame());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
最佳答案
该位置存储在变量x和y中。运动的“速度”简单地通过按键上这些变量的变化率来描述。简短地看一下代码，就会发现此“速度”相当笨拙地设置为5。它出现在四个不同的位置-每个方向向量一次。要更改“速度”，您可以更改所有这些事件，但是请记住，如果忘记更改其中一些事件，则对象将以不同的速度沿不同的方向移动！
您可以通过用命名变量替换所有magic numbers来大大改进此代码。这不仅包括“速度”，还包括运动边界：8，18，435和325。将这些命名变量放在AL类或JavaGame类中，具体取决于需要在何处使用它们。
我还要提到一个不相关的错误。您当前的代码将允许您越界，然后在随后的按键上，由于“剪切”而沿相反的方向移动。例如，说x = 10。如果按向左键，则将x更改为5。如果然后再次按向左键，则边界条件将触发并且向右移动，将x设置为8。这可能是不希望的，因此您应该首先应用移动，然后剪辑到边界。
您的AL类（还应考虑使用更具描述性的名称...）可能看起来像这样：
public class AL extends KeyAdapter {
private static final int SPEED = 5; // Controls the movement speed in all directions
// Variables controlling the movement boundaries
private static final int BOUND_LEFT = 8;
private static final int BOUND_RIGHT = 435;
private static final int BOUND_BOTTOM = 18;
private static final int BOUND_TOP = 325;
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == e.VK_LEFT) {
x -= SPEED; // Move left
if (x <= BOUND_LEFT) {
x = BOUND_LEFT; // If movement placed us out of bounds, move to boundary instead
}
}
if (keyCode == e.VK_RIGHT) {
x += SPEED;
if (x >= BOUND_RIGHT) {
x = BOUND_RIGHT;
}
}
if (keyCode == e.VK_UP) {
y += SPEED;
if (y >= BOUND_TOP) {
y = BOUND_TOP;
}
}
if (keyCode == e.VK_DOWN) {
y -= SPEED;
if (y <= BOUND_BOTTOM) {
y = BOUND_BOTTOM;
}
}
}
public void keyReleased(KeyEvent e) {
}
}
关于java - 如何在此代码中更改幻影速度，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/27784718/