java键盘事件

[zhouwenb345]

在以下程序中我想在红色字体（或******处）处写入一句if语句，
当开始按键盘方向键的时候跳出循环，从而转向执行该按键事件，不知道这个if语句的条件怎么写？
请各位指点指点！
在此谢谢咯！
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;


public class Test2 extends Applet implements KeyListener{
int x = 0,y = 0;
int r = 20;

public void init(){
this.addKeyListener(this);
}

public void paint(Graphics g){
g.setColor(Color.red) ;
g.fillOval(x, y, r,r) ;

}

public void keyPressed(KeyEvent e) {
switch(e.getKeyCode())
{ case KeyEvent.VK_LEFT:


x = x - 2 ;
if( x<= 0 ) x = 800;
setLocation(x, y) ; break ;
case KeyEvent.VK_RIGHT:

{
x = x + 2 ;
if( x>800 ) x = 0 ;
setLocation( x, y ) ;
break ;
}

case KeyEvent.VK_UP:
{
y = y - 2 ;
if(y<=0)
y=600;
setLocation(x, y);
break;
}
case KeyEvent.VK_DOWN:
{
y = y + 2;
if(y>=600) y = 0 ;
setLocation(x, y) ;
break;
}

}

}
public void keyReleased(KeyEvent e) {
switch(e.getKeyCode())
{ case KeyEvent.VK_LEFT:
while(true)
{x = x - 2 ; setLocation( x, y );
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

****** if()break;
if( x<= 0 ) {
x = 800;
break;}
}
case KeyEvent.VK_RIGHT:
while(true){
x = x + 2 ; setLocation( x, y ) ;
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

if( x>800 ){
x = 0 ;
//setLocation( x, y ) ;
break ;}
}

case KeyEvent.VK_UP:
while(true){
y = y - 2 ; setLocation( x, y ) ;
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

if(y<=0){
y=600;
//setLocation(x, y);
break;}
}
case KeyEvent.VK_DOWN:
while(true){
y = y + 2; setLocation( x, y ) ;
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

if(y>=600){
y = 0 ;
//setLocation(x, y) ;
break;}
}

}


}
public void keyTyped(KeyEvent e) {
}
}

[yanhan0615]

楼主，这样做的结构不好，换一种思路看看；
你的代码应该是用按键驱动一个东西在屏幕上跑，这算是一个最基本的游戏，在处理按键的时候，应该把逻辑处理和按键监听分开来，大体思路是：开一个线程来做一个循环，用线程来驱动每一帧，在驱动中去检测一个整形变量keyCode，分辨这个值并且对应的去处理；在按键中，只需要把你的按键值取到，并且赋值到keyCode就可以了

[一洽客服系统]

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;


public class Test2 extends Applet implements KeyListener{
int x = 0,y = 0;
int r = 20;
private int flag = 0;
public void init(){
this.addKeyListener(this);
}

public void paint(Graphics g){
g.setColor(Color.red) ;
g.fillOval(x, y, r,r) ;

}

public void keyPressed(KeyEvent e) {
switch(e.getKeyCode())
{ case KeyEvent.VK_LEFT:
flag = 1;

x = x - 2 ;
if( x <= 0 ) x = 800;
setLocation(x, y) ; break ;
case KeyEvent.VK_RIGHT:

{
flag = 2;

x = x + 2 ;
if( x>800 ) x = 0 ;
setLocation( x, y ) ;
break ;
}

case KeyEvent.VK_UP:
{
flag = 3;

y = y - 2 ;
if(y <=0)
y=600;
setLocation(x, y);
break;
}
case KeyEvent.VK_DOWN:
{
flag = 4;

y = y + 2;
if(y>=600) y = 0 ;
setLocation(x, y) ;
break;
}

}

}
public void keyReleased(KeyEvent e) {
switch(e.getKeyCode())
{ case KeyEvent.VK_LEFT:
]
while(true&&flag ==1)
{x = x - 2 ; setLocation( x, y );
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

****** if()break;
if( x <= 0 ) {
x = 800;
break;}
}
case KeyEvent.VK_RIGHT:
while(true&&flag ==2){
x = x + 2 ; setLocation( x, y ) ;
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

if( x>800 ){
x = 0 ;
//setLocation( x, y ) ;
break ;}
}

case KeyEvent.VK_UP:
while(true&&flag ==3){
y = y - 2 ; setLocation( x, y ) ;
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

if(y <=0){
y=600;
//setLocation(x, y);
break;}
}
case KeyEvent.VK_DOWN:
while(true&&flag ==4){
y = y + 2; setLocation( x, y ) ;
try {
Thread.sleep(100);
}
catch (InterruptedException e1) {

e1.printStackTrace();
}

if(y>=600){
y = 0 ;
//setLocation(x, y) ;
break;}
}

}


}
public void keyTyped(KeyEvent e) {
}
}

[一洽客服系统]

在你基础上家了红色那几行 我没有测试 不过应该能满足你的要求

[kk19860205]

import java.applet.Applet;
import java.awt.Button;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class Dest extends Applet implements KeyListener
{


int x,y;
int w=0;
public void start()
{
x=100;
y=100;
}


public void init()
{

this.addKeyListener(this);

}


public void paint(Graphics g)
{

g.setColor(Color.red);
g.fillOval(x,y,10,10);
if(w==1)
{
if(x<=0)
x=1024;
else x=x-3;
try
{
Thread.sleep(20);
}
catch(InterruptedException k)
{
return;
}
repaint();
}

if(w==2)
{
if(x>=1024)
x=0;
else x=x+3;
try
{
Thread.sleep(20);
}
catch(InterruptedException e)
{
return;
}
repaint();
}

if(w==3)
{
if(y<=0)
y=768;
else y=y-3;
try
{
Thread.sleep(20);
}
catch(InterruptedException e)
{
return;
}
repaint();
}
if(w==4)
{
if(y>=768)
y=0;
else y=y+3;
try
{
Thread.sleep(20);
}
catch(InterruptedException e)
{
return;
}
repaint();
}


}

public void keyPressed(KeyEvent e) {
switch(e.getKeyCode())
{
case KeyEvent.VK_LEFT:
w=1;

repaint();
break;
case KeyEvent.VK_RIGHT:
w=2;
repaint();
break;
case KeyEvent.VK_UP:
w=3;
repaint();
break;

case KeyEvent.VK_DOWN:
w=4;
repaint();
break;

}
}
public void keyReleased(KeyEvent e) {}
public void keyTyped(KeyEvent e) {}



}