【发布时间】：2013-04-01 02:21:20
【问题描述】：
我遵循了某人在另一个问题上发布的示例，用于控制对象的键绑定。为简单起见，它所控制的只是在按下 VK_UP 时打印“woo”，但它不会那样做。
来自here 的一些代码我仍然无法正常工作。
这是主要的
import javax.swing.*;
@SuppressWarnings("serial")
public class apples extends JFrame {
static boolean running;
public static void main(String[] args){
JFrame f = new JFrame();
Peach p = new Peach();
f.getContentPane().add(new test());
f.add(new test());
f.add(p);
f.setSize(400,250);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
p.run();
}
}
这里是键绑定的东西
import java.awt.*;
import java.awt.event.*;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;
@SuppressWarnings("serial")
public class Peach extends JPanel {
public void paint(Graphics g){
setOpaque(false);
super.paintComponent(g);
this.setBackground(Color.WHITE);
g.setColor(Color.BLACK);
g.fillOval(x, y, br, br);
g.drawString("Sort of Pong?", 157, 20);
g.setColor(Color.BLACK);
g.fillRect(paddlex, paddley, psizex, psizey);
//g.setColor(new Color(51, 255, 204));
//g.fillRect(100, 100, 80, 100);
repaint();
}
public void Panel(){ Thread go = new Thread();
go.start(); }
int xpos;
final int left = -1; //left increment
final int right = 1; //right increment
int up = -1; // up increment (negative because down is revered in coordinates)
int down = 1; // down increment
boolean check = true; // moving or not
int x =200; // ball position x
int y=100; // ball position y
boolean rightmove = true; // moving right or left
boolean leftmove = false; // moving left
boolean upmove = true; // moving up
boolean downmove = false; // moving down
int paddlex = 100; // paddle position x
int paddley = 100; // paddle position y
int psizex = 100; // paddle size in x dimension
int psizey = 100; // paddles size in y dimension
int cdy; // for checking other side for collisions
int cdx; // for checking other side for collisions
int br = 8; // ball radius
boolean shipupmove = false;
boolean shipdownmove = true;
int shipspeed = 1;
boolean goup;
long counter = 0;
public void calc(){
cdy = psizey + paddley; // for checking other side for collisions
cdx = psizex + paddlex; // for checking other side for collisions
}
public void run(){
while(true){
move();
collisiond();
calc();
counter++;
try
{
Thread.sleep(8);
}
catch(InterruptedException ex)
{
}
}
}
public void move(){
if (rightmove){
if(x <377){
x = (x+right);
}else{rightmove = false; leftmove = true;}
}
if(leftmove)
if(x > 0){
x = (x-right);
}else{rightmove = true; leftmove= false;}
if (downmove){
if(y <205){
y = (y+down);
}else{downmove = false; upmove = true;}
}
if(upmove)
if(y > 0){
y = (y+up);
}else{downmove = true; upmove= false;}
}
public void collisiond(){
if(leftmove && (x ==(cdx+1) || x == (cdx-1) || x == cdx)&& y >= paddley-br && y <= cdy){
leftmove = false; rightmove = true;
}
if(rightmove && (x ==(paddlex-br+1) || x == (paddlex-br-1) || x == paddlex-br) && y >= paddley && y <= cdy){
rightmove = false; leftmove = true;
}
if(upmove && ((y == cdy+1) || (y == cdy-1) || (y == cdy)) && x >= paddlex && x<= cdx){
upmove = false; downmove = true;
}
if(downmove && ((y == paddley - br +1) || (y == paddley - br -1) || (y == paddley - br)) && x > paddlex && x < cdx){
downmove = false; upmove = true;
}
}
public void movepaddle(){
if(shipupmove && paddley !=0){
this.paddley = paddley - 1 ;
}
if (shipdownmove && paddley < (205-psizey)){
this.paddley = paddley + 1;
}
if(paddley < 16){
shipupmove = false; shipdownmove = true;
}
if(cdy > 189){
shipupmove = true; shipdownmove = false;
}
repaint();
}
}
class test extends JPanel{
private static final long serialVersionUID = 1L;
private Map<Direction, Boolean> directionMap = new HashMap<Direction, Boolean>();
int DELAY = 5;
enum Direction {
UP(KeyEvent.VK_UP,true),
DOWN(KeyEvent.VK_DOWN, false);
private int KeyCode;
boolean moveing;
Direction(int KeyCode, boolean moveing) {
this.KeyCode = KeyCode;
this.moveing = moveing;
}
public int getKeyCode(){
return KeyCode;
}
public boolean moveing(){
return moveing;
}
}
public test(){
for(Direction direction : Direction.values()){
directionMap.put(direction, false);
}
setBindings();
Timer timer = new Timer(5, new TimerListener());
timer.start();
}
private void setBindings(){
InputMap in = getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
ActionMap act = getActionMap();
for(final Direction d : Direction.values()){
KeyStroke press = KeyStroke.getKeyStroke(d.getKeyCode(), 0 ,false);
KeyStroke rel = KeyStroke.getKeyStroke(d.getKeyCode(),0,true);
in.put(press, "key pressed");
in.put(rel, "key released");
act.put(d.toString()+"pressed", new AbstractAction(){
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent e) {
directionMap.put(d, true);
}
});
act.put(d.toString()+"released", new AbstractAction(){
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent e) {
directionMap.put(d, false);
}
});
}
}
public class TimerListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
for(Direction d : Direction.values()){
if(directionMap.get(d)){
if(d.moveing()){
System.out.println("woo");
}
}
}
}
}
}
任何见解将不胜感激，谢谢
【问题讨论】：
-
Peach 类到底是什么？它的代码在哪里？你知道吗，通过将它添加到 JFrame 的 contentPane 中，你会掩盖之前添加的组件。此外，apples（更好，Apples）类不应该扩展 JFrame，因为它的行为不像 JFrame。最后，如果您希望其他人能够更好地理解您的代码，请遵守 Java 的命名约定。
-
顺便说一下，其中一些代码看起来像我的，或者我的 mKorbel 代码。此外，您不应该将测试类 twice 添加到 JFrame。
-
Peach 课程专注于一些基本物理的小动画，但它不相关，所以我没有包括它。对于任何命名错误，我深表歉意，我会努力使其更简洁。
-
通过在上面的代码中保留您的 Peaches 代码，您的代码对于我们来说是不可编译的。以后请避免这种情况。
-
顺便说一下，您的 paint() 方法完全搞砸了。首先，您应该覆盖paintComponent() 而不是paint()。您不应该更改 peinting 方法中的组件属性（即 setOpaque()、setBackground()）。而且您绝对不想在方法中调用 repaint() 。是时候阅读Swing tutorial了。它包含有关如何正确执行“自定义绘画”的部分以及有关键绑定的部分。
标签： java swing key-bindings key-events