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[英]I Need help to move a Image Icon across the screen in java with a Jbutton ActionListener
[英]I Need to help to move an image across the screen
我在做游戲,我從電腦上拍攝的圖像在屏幕上沒有移動,出了點問題,請幫幫我
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import javax.swing.ImageIcon;
public class Player extends Entity{
int velX=0,velY=0, speed =5;
public Player(int x, int y) {
super(x, y);
}
public void Update(){
y+=velY;
x+=velX;
checkCollision();
}
public void draw(Graphics2D g2d){
g2d.drawImage(getPlayerImage(),x,y, null);
g2d.draw(getbounds());
}
public Image getPlayerImage(){
ImageIcon ic = new ImageIcon("D:/abc.png");
return ic.getImage();
}
public void KeyPressed(KeyEvent e){
int key = e.getKeyCode();
if(key== KeyEvent.VK_UP) velY=-speed;
else if(key==KeyEvent.VK_DOWN) velY=speed;
if(key==KeyEvent.VK_LEFT) velX-=speed;
else if(key==KeyEvent.VK_RIGHT) velX=speed;
else if(key==KeyEvent.VK_SPACE) GameFrame.addMissile(new Missile(x,y));
}
public void KeyReleased(KeyEvent e){
int key = e.getKeyCode();
if(key== KeyEvent.VK_UP)velY=0;
else if(key==KeyEvent.VK_DOWN) velY=0;
if(key==KeyEvent.VK_LEFT) velX=0;
else if(key==KeyEvent.VK_RIGHT) velX=0;
}
public void checkCollision(){
ArrayList<Enemy> enemies = GameFrame.getEnemyList();
for(int i=0; i<enemies.size(); i++){
Enemy tempEnemy = enemies.get(i);
if(getbounds().intersects(enemies.get(i).getbounds())) System.exit(0);
}
}
public Rectangle getbounds(){
return new Rectangle(x,y,getPlayerImage().getWidth(null),getPlayerImage().getHeight(null));
}
}
還有另外7個類別,但圖像移動工作在此處,還有一個KeyAdapt類別,該類別僅用作keyadapter
您應該在按下鼠標時查看要移動的內容,但這取決於您向左還是向右移動,應該減小還是增大。 向上或向下相同。
因此,當您向上和向下移動時,您將沿Y軸移動,該軸以0向北(向上)開始,以Y最大值的南側(向下)結束,因此,如果您要向上移動,請執行velY-=速度,並且如果要下去,你的速度就快了。 假設當時的velY為0,並且速度大於0。
X軸也一樣,左為0,右為X的最大值。向左移動時,從0減小(velX:-5),向右移動時從0增大(velX:+5)。
另一件事是,當您多次需要ImageIcon時,最好將其設置為私有屬性,因為那樣只會實例化一次。 這將大大提高您的性能,因為每次使用位於硬盤驅動器上的映像實例化ImageIcon時,您都會執行磁盤IO操作,這會使所有操作變慢。
命名在Java中也很重要,因為用不正確的大寫字母寫方法名稱。 方法名稱應以小寫字母開頭,並使用駝峰式。
我用switch case語句重寫了您的代碼,以使其更具可讀性。
public class Player extends Entity {
private int velX=0,velY=0, speed =5;
private ImageIcon ic = new ImageIcon("D:/abc.png");
public Player(int x, int y) {
super(x, y);
}
@Override
public void update(){
y+=velY;
x+=velX;
checkCollision();
}
public void draw(Graphics2D g2d){
g2d.drawImage(getPlayerImage(),x,y, null);
g2d.draw(getbounds());
}
public Image getPlayerImage(){
return ic.getImage();
}
public void keyPressed(KeyEvent e){
switch (e.getKeyCode()) {
case KeyEvent.VK_UP: velY -= speed; break;
case KeyEvent.VK_DOWN: velY += speed; break;
case KeyEvent.VK_LEFT: velX -= speed; break;
case KeyEvent.VK_RIGHT: velX += speed; break;
case KeyEvent.VK_SPACE: GameFrame.addMissile(new Missile(x,y)); break;
default: break;
}
}
public void keyReleased(KeyEvent e){
switch (e.getKeyCode()) {
case KeyEvent.VK_UP: velY = 0; break;
case KeyEvent.VK_DOWN: velY = 0; break;
case KeyEvent.VK_LEFT: velX = 0; break;
case KeyEvent.VK_RIGHT: velX = 0; break;
default: break;
}
}
public void checkCollision(){
ArrayList<Enemy> enemies = GameFrame.getEnemyList();
for(int i=0; i<enemies.size(); i++){
Enemy tempEnemy = enemies.get(i);
if(getbounds().intersects(enemies.get(i).getbounds())) System.exit(0);
}
}
public Rectangle getbounds(){
return new Rectangle(x,y,getPlayerImage().getWidth(null),getPlayerImage().getHeight(null));
}
}
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