我試圖運行我寫了一個移動的球一碼(對不起,如果代碼是凌亂...我不是很有經驗......)它不顯示任何錯誤消息,但是當我點擊的appletviewer並按下鍵,球不會改變它的方向。爲什麼會發生? p.s.我使用「eclipse」編寫我的代碼是一個好的編譯器嗎?也許問題在那裏?爲什麼Keylistener不工作?
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
public class Main extends Applet implements KeyListener {
private static final long serialVersionUID = 7526472295622776147L;
boolean right=true;
boolean left=false;
boolean up=false;
boolean down=false;
boolean inGame=true;
public void listen(){
addKeyListener((KeyListener) this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void keyPressed(KeyEvent e){}
public void keyTyped(KeyEvent e){
int key = e.getKeyCode();
if (key == KeyEvent.VK_LEFT) {
left=true;
up=false;
down=false;
}
if (key == KeyEvent.VK_RIGHT) {
right=true;
up=false;
down=false;
}
if (key == KeyEvent.VK_UP) {
up=true;
right=false;
left=false;
}
if (key == KeyEvent.VK_DOWN) {
down=true;
right=false;
left=false;
}
}
public void keyReleased(KeyEvent e){}
int x1=5;
int y1=5;
int x2=x1+5;
int y2=y1+5;
public int moveRight(){
return ++x1;
}
public int moveLeft(){
return --x1;
}
public int moveUp(){
return ++y1;
}
public int moveDown(){
return --y1;
}
public void paint1(Graphics g){
g.drawOval(x1,y1,x2,y2);
}
public void paint(Graphics e){
long millis =System.currentTimeMillis();
long millisn =System.currentTimeMillis();
while (right=true){
millis =System.currentTimeMillis();
millisn =System.currentTimeMillis();
while (millisn<millis+20){
millisn=System.currentTimeMillis();
}
e.setColor(Color.white);
e.drawOval(x1,y1,x2,y2);
e.setColor(Color.red);
moveRight();
e.drawOval(x1,y1,x2,y2);
}
while(inGame==true){
if(right==true){
millis =System.currentTimeMillis();
millisn =System.currentTimeMillis();
while (millisn<millis+20){
millisn=System.currentTimeMillis();
}
e.setColor(Color.white);
e.drawOval(x1,y1,x2,y2);
e.setColor(Color.red);
moveRight();
e.drawOval(x1,y1,x2,y2);
listen();
}
else if(down==true){
millis =System.currentTimeMillis();
millisn =System.currentTimeMillis();
while (millisn<millis+20){
millisn=System.currentTimeMillis();
}
e.setColor(Color.white);
e.drawOval(x1,y1,x2,y2);
e.setColor(Color.red);
moveDown();
e.drawOval(x1,y1,x2,y2);
}
else if (left==true){
millis =System.currentTimeMillis();
millisn =System.currentTimeMillis();
while (millisn<millis+20){
millisn=System.currentTimeMillis();
}
e.setColor(Color.white);
e.drawOval(x1,y1,x2,y2);
e.setColor(Color.red);
moveLeft();
e.drawOval(x1,y1,x2,y2);
}}
}
}
拍攝缺憾的能力的關鍵綁定API大概是因爲沒有按小程序沒有鍵盤焦點。另外,不要忘記調用super.paint – MadProgrammer
但我沒有設置可聚焦爲「true」 – Atlantis
這僅僅意味着小程序可以接收鍵盤焦點,並不在於它具有鍵盤焦點 – MadProgrammer