Java 学习关键事件
我对java还比较陌生,我试图学习如何在有这个圆圈的地方制作一个程序,我可以使用箭头键来移动它。通过一系列的例子,我能够把一些东西组合起来。尽管我不确定如何创建KeyEvent。我所缺少的任何帮助都将是非常棒的 这就是我目前所拥有的Java 学习关键事件,java,swing,Java,Swing,我对java还比较陌生,我试图学习如何在有这个圆圈的地方制作一个程序,我可以使用箭头键来移动它。通过一系列的例子,我能够把一些东西组合起来。尽管我不确定如何创建KeyEvent。我所缺少的任何帮助都将是非常棒的 这就是我目前所拥有的 import javax.swing.WindowConstants; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import
import javax.swing.WindowConstants;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.Color;
import java.awt.event.KeyEvent;
@SuppressWarnings("serial")
public class Game extends JPanel
{
int x = 0;
int y = 0;
private void moveBallUP() {
x = x + 0;
y = y + 1;
}
private void moveBallDOWN() {
x = x + 0;
y = y - 1;
}
private void moveBallLEFT() {
x = x + 1;
y = y + 0;
}
private void moveBallRIGHT() {
x = x - 1;
y = y + 0;
}
@Override
public void paint(Graphics g)
{
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(Color.red);
g2d.fillOval(y, x, 50, 50);
}
public static void main(String[] args) throws InterruptedException
{
JFrame frame = new JFrame("Sample Frame");
Game game = new Game();
frame.add(game);
frame.setSize(300, 400);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
if (event.getKeyCode() == KeyEvent.VK_UP)
{
game.moveBallUP();
game.repaint();
Thread.sleep(10);
}
if (event.getKeyCode() == KeyEvent.VK_DOWN)
{
game.moveBallDOWN();
game.repaint();
Thread.sleep(10);
}
if (event.getKeyCode() == KeyEvent.VK_LEFT)
{
game.moveBallLEFT();
game.repaint();
Thread.sleep(10);
}
if (event.getKeyCode() == KeyEvent.VK_RIGHT)
{
game.moveBallRIGHT();
game.repaint();
Thread.sleep(10);
}
}
}
解决这个问题有几个步骤:首先,使用
keylister
。将以下代码添加到游戏
类中;这将表示按下了哪些按钮:
private boolean upPressed=false;
private boolean downPressed=false;
private boolean leftPressed=false;
private boolean rightPressed=false;
然后,将其添加到main
方法中:
frame.addKeyListener(new KeyListener() {
@Override
public void keyReleased(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=false;
break;
case KeyEvent.VK_DOWN:
game.downPressed=false;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=false;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=false;
break;
}
}
@Override
public void keyTyped(KeyEvent event) {
}
@Override
public void keyPressed(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=true;
break;
case KeyEvent.VK_DOWN:
game.downPressed=true;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=true;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=true;
break;
}
}
});
Timer timer = new Timer(10,(e)->{
if (game.upPressed)
{
game.moveBallUP();
game.repaint();
}
if (game.downPressed)
{
game.moveBallDOWN();
game.repaint();
}
if (game.leftPressed)
{
game.moveBallLEFT();
game.repaint();
}
if (game.rightPressed)
{
game.moveBallRIGHT();
game.repaint();
}
});
timer.start();
基本上,当按下按钮时,将我们创建的变量设置为true,当释放按钮时,将设置为false。最后,在main
方法中添加一个Timer
:
frame.addKeyListener(new KeyListener() {
@Override
public void keyReleased(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=false;
break;
case KeyEvent.VK_DOWN:
game.downPressed=false;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=false;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=false;
break;
}
}
@Override
public void keyTyped(KeyEvent event) {
}
@Override
public void keyPressed(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=true;
break;
case KeyEvent.VK_DOWN:
game.downPressed=true;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=true;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=true;
break;
}
}
});
Timer timer = new Timer(10,(e)->{
if (game.upPressed)
{
game.moveBallUP();
game.repaint();
}
if (game.downPressed)
{
game.moveBallDOWN();
game.repaint();
}
if (game.leftPressed)
{
game.moveBallLEFT();
game.repaint();
}
if (game.rightPressed)
{
game.moveBallRIGHT();
game.repaint();
}
});
timer.start();
这将每10毫秒触发一次,并在按下按钮时调用移动方法
我已经测试过了,并且知道它是有效的,但是你的移动方法将圆移动到了错误的方向。我想你能解决这个问题
编辑:错误在这一行:
g2d.fillOval(y, x, 50, 50);
将其更改为:
g2d.fillOval(x,y , 50, 50);
解决这个问题有几个步骤:首先,使用
keylister
。将以下代码添加到游戏
类中;这将表示按下了哪些按钮:
private boolean upPressed=false;
private boolean downPressed=false;
private boolean leftPressed=false;
private boolean rightPressed=false;
然后,将其添加到main
方法中:
frame.addKeyListener(new KeyListener() {
@Override
public void keyReleased(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=false;
break;
case KeyEvent.VK_DOWN:
game.downPressed=false;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=false;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=false;
break;
}
}
@Override
public void keyTyped(KeyEvent event) {
}
@Override
public void keyPressed(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=true;
break;
case KeyEvent.VK_DOWN:
game.downPressed=true;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=true;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=true;
break;
}
}
});
Timer timer = new Timer(10,(e)->{
if (game.upPressed)
{
game.moveBallUP();
game.repaint();
}
if (game.downPressed)
{
game.moveBallDOWN();
game.repaint();
}
if (game.leftPressed)
{
game.moveBallLEFT();
game.repaint();
}
if (game.rightPressed)
{
game.moveBallRIGHT();
game.repaint();
}
});
timer.start();
基本上,当按下按钮时,将我们创建的变量设置为true,当释放按钮时,将设置为false。最后,在main
方法中添加一个Timer
:
frame.addKeyListener(new KeyListener() {
@Override
public void keyReleased(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=false;
break;
case KeyEvent.VK_DOWN:
game.downPressed=false;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=false;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=false;
break;
}
}
@Override
public void keyTyped(KeyEvent event) {
}
@Override
public void keyPressed(KeyEvent event) {
switch (event.getKeyCode()) {
case KeyEvent.VK_UP:
game.upPressed=true;
break;
case KeyEvent.VK_DOWN:
game.downPressed=true;
break;
case KeyEvent.VK_LEFT:
game.leftPressed=true;
break;
case KeyEvent.VK_RIGHT:
game.rightPressed=true;
break;
}
}
});
Timer timer = new Timer(10,(e)->{
if (game.upPressed)
{
game.moveBallUP();
game.repaint();
}
if (game.downPressed)
{
game.moveBallDOWN();
game.repaint();
}
if (game.leftPressed)
{
game.moveBallLEFT();
game.repaint();
}
if (game.rightPressed)
{
game.moveBallRIGHT();
game.repaint();
}
});
timer.start();
这将每10毫秒触发一次,并在按下按钮时调用移动方法
我已经测试过了,并且知道它是有效的,但是你的移动方法将圆移动到了错误的方向。我想你能解决这个问题
编辑:错误在这一行:
g2d.fillOval(y, x, 50, 50);
将其更改为:
g2d.fillOval(x,y , 50, 50);
“我对java比较陌生”-欢迎,使用注册特定关键事件的通知作为一般建议,您应该覆盖
paintComponent
,而不是paint
。您还可以在“事件驱动”环境中操作,该环境使用观察者模式在事件发生时提供通知。使用Swing时,还应避免使用ad.sleep,因为这样可以防止UI被更新或无法响应新事件“我对java比较陌生”-欢迎使用注册特定关键事件的通知作为一般建议,您应该覆盖paintComponent
,而不是paint
。您还可以在“事件驱动”环境中操作,该环境使用观察者模式在事件发生时提供通知。使用Swing时,您还应避免使用Thead.sleep
,因为您可能会阻止用户界面被更新或无法对新事件做出响应。由于回复太晚,这对您帮助很大。对于回复太晚,我深表歉意,但非常感谢。