【发布时间】：2016-03-12 20:18:49
【问题描述】：
当我运行代码时，添加到 JOptionPane 的 Example1 类（在 Frame 中）应该获取 keyInput，然后更改播放器实例的 y 值（在 example1 中），但它不起作用。另外，我怎样才能使船绕其轴旋转，然后朝其面对的方向移动？目前，它沿其旋转方向移动，但它似乎在坐标 0,0 上旋转。
框架
import javax.swing.*;
import java.awt.*;
/**
* Created by griffin on 12/7/2015.
*/
public class Frame extends JFrame {
public Frame() {
initUI();
}
private void initUI() {
JTabbedPane jtp = new JTabbedPane();
Example1 e1 = new Example1();
Example2 e2 = new Example2();
getContentPane().add(jtp);
jtp.add(e1);
jtp.add(e2);
jtp.addTab("Example 1", e1);
jtp.addTab("Example 2", e2);
setResizable(false);
pack();
setTitle("NLTP");
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new Frame();
frame.setVisible(true);
}
});
}
}
示例 1
import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.AffineTransform;
/**
* Created by griffin on 12/7/2015.
*/
public class Example1 extends JPanel implements Runnable {
private final int B_WIDTH = 640;
private final int B_HEIGHT = 480;
private int DELAY = 25;
private Thread thread;
Ship player = new Ship(320, 240);
public Example1() {
initScreen();
}
private void initScreen() {
JButton explanation = new JButton("Explanation");
explanation.setBounds(0, 0, 150, 30);
this.setLayout(null);
add(explanation);
addKeyListener(new keyInput());
setFocusable(true);
setBackground(Color.BLACK);
setPreferredSize(new Dimension(B_WIDTH, B_HEIGHT));
setDoubleBuffered(true);
}
@Override
public void addNotify() {
super.addNotify();
thread = new Thread(this);
thread.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
draw(g);
}
public void draw(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
AffineTransform old = g2d.getTransform();
g2d.rotate(Math.toRadians(player.angle));
g2d.drawImage(player.ship, player.x, player.y, null);
g2d.setTransform(old);
Toolkit.getDefaultToolkit().sync();
}
public void cycle() {
player.y += player.vY;
}
@Override
public void run() {
long beforeTime, timeDiff, sleep;
beforeTime = System.currentTimeMillis();
while (true) {
cycle();
repaint();
timeDiff = System.currentTimeMillis() - beforeTime;
sleep = DELAY - timeDiff;
if (sleep < 0) {
sleep = 2;
}
try {
Thread.sleep(sleep);
} catch (InterruptedException e) {
System.out.println("Interrupted: " + e.getMessage());
}
beforeTime = System.currentTimeMillis();
}
}
public class keyInput extends KeyAdapter {
@Override
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_W) {
}
}
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_W) {
player.vY -= 1;
}
if(key == KeyEvent.VK_A) {
player.angle++;
}
if(key == KeyEvent.VK_D) {
player.angle--;
}
}
}
}
【问题讨论】：
-
不要从
draw调用super.paintComponent(g);，你最终会得到一个StackOverflowException；在 Swing 15 年多的时间里，我从来没有需要打电话给Toolkit.getDefaultToolkit().sync(); -
KeyListener以在键盘焦点方面存在问题而闻名，请改用键绑定 API。见How to Use Key Bindings -
那么，您想知道如何解决您的按键输入/对焦问题、绘画问题或移动问题吗？
-
如果你愿意帮忙的话。我的主要问题是按键输入。我查看了用于键绑定的 API，但似乎无法将其正确应用到我的程序中。
标签： java swing jframe jpanel joptionpane