我正在尝试用Java编写Pong applet。当用户向上或向下按住时,他们的拨片应该平稳移动,但事实并非如此。它移动,然后暂停,然后再次开始移动。有没有办法阻止这种短暂停顿?
主类:
public class Main extends JApplet {
public DrawPanel dp = new DrawPanel(400, 400);
public void init(){
add(dp);
setSize(400, 400);
requestFocusInWindow();
Action moveDown = new AbstractAction(){
public void actionPerformed(ActionEvent e){
dp.player.y += 10;
dp.repaint();
}
};
dp.getInputMap().put(KeyStroke.getKeyStroke("pressed DOWN"), "move down");
dp.getActionMap().put("move down", moveDown);
}
}
DrawPanel类:
public class DrawPanel extends JPanel {
public Paddle player;
public Paddle opponent;
public DrawPanel(int height, int width){
int y = (height / 2) - (height / 10);
int w = 15;
int h = height / 5;
player = new Paddle(2, y, 15, h, Color.white);
opponent = new Paddle(width - (w+2), y, 15, h, Color.white);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
this.setBackground(Color.BLACK);
g.setColor(player.color);
g.fillRect(player.x, player.y, player.width, player.height);
g.setColor(opponent.color);
g.fillRect(opponent.x, opponent.y, opponent.width, opponent.height);
}
}
桨类:
public class Paddle {
public int x, y, width, height;
public Color color;
public Paddle(int _x_, int _y_, int w, int h, Color c){
x = _x_;
y = _y_;
width = w;
height = h;
color = c;
}
}
答案 0 :(得分:4)
潜在问题是keyPressed的“实例”概念与运动的“持续时间”概念之间的阻抗不匹配。
不要试图在视图中平滑过度(不应该与游戏逻辑的细节有任何关系),而是使用更合适的api来增强游戏模型。 F.i.添加启动/停止逻辑并将这些方法绑定到keyPressed / keyReleased:
public class Paddle {
public void startMoveDown() {
// here goes the logic, f.i. starting a timer
// in the actionPerformed of that timer:
... moveUnitDown();
}
public void stopMoveDown() {
//...
}
protected void moveUnitDown() {
y+=unit;
// ideally, have listeners and notify them the change of y
}
}
// in the view:
Action startMoveDown = new AbstractAction(){
public void actionPerformed(ActionEvent e){
player.startMoveDown();
}
};
dp.getInputMap().put(KeyStroke.getKeyStroke("pressed DOWN"), "start move down");
dp.getActionMap().put("start move down", startMoveDown);
// in the view:
Action stopMoveDown = new AbstractAction(){
public void actionPerformed(ActionEvent e){
player.stopMoveDown();
}
};
dp.getInputMap().put(KeyStroke.getKeyStroke("released DOWN"), "stop move down");
dp.getActionMap().put("stop move down", stopMoveDown);