缓冲键盘输入

时间:2013-05-09 08:47:48

标签: java swing keylistener paintcomponent event-dispatch-thread

我正在尝试编写一个2D图形游戏。在这个游戏中,我有键盘输入在黑色平面上移动方块。我命令确保我想要使用缓冲键输入的平滑键运动。为了做到这一点,我使用一个保存击键的布尔数组。

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Timer;

import javax.swing.JFrame;
import javax.swing.JPanel;


public class Main extends JFrame{

/**
 * @param args
 */
class Entity
{
    int x = 150,y = 150;
    int  Speed = 5;

}

Entity user = new Entity();
boolean[] keys = new boolean[KeyEvent.KEY_TYPED];

public Main()
{
    setSize(800,600);
    setLocationRelativeTo(null);

    final JPanel display = new JPanel()
    {
        protected void paintComponent(Graphics g)
        {

            g.setColor(Color.black);
            g.fillRect(0, 0, getWidth(), getHeight());
            g.setColor(Color.RED);
            g.fillRect(user.x, user.y, 30, 30);
        }
    };


    addKeyListener(new KeyAdapter() 
    {

        public void keyPressed(KeyEvent arg0)
        {

            keys[arg0.getKeyCode()] = true;

            if(keys[KeyEvent.VK_UP])
            {
                user.y -= user.Speed;

            }
            if(keys[KeyEvent.VK_DOWN])
            {
                user.y += user.Speed;
            }
            if(keys[KeyEvent.VK_LEFT])
            {
                user.x -= user.Speed;
            }
            if(keys[KeyEvent.VK_RIGHT])
            {
                user.x += user.Speed;

            }

            setFocusable(true);
            repaint();

        }
    });


    //add a action listener
    //remember to set the focusable 


    add(display);
}
public static void main(String[] args) {
    // TODO Auto-generated method stub


    Thread t = new Thread();
    try {
        t.sleep(100);
        Main m = new Main();
        m.setVisible(true);
        m.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }   
}

}

在此输入中,块以正确的方向移动,但只移动两次,然后以不同的方式移动,甚至停止移动。

我在我所有的Java书籍中搜索过我所拥有的内容并没有多大帮助。如何修复此错误?

1 个答案:

答案 0 :(得分:1)

使boolean[] keys成为局部变量,使其不包含先前按下的键,这将影响x,y坐标。

public void keyPressed(KeyEvent arg0)
{
    boolean[] keys = new boolean[KeyEvent.KEY_TYPED];
    keys[arg0.getKeyCode()] = true;

    if(keys[KeyEvent.VK_UP])
    {
        user.y -= user.Speed;
    }
    else if(keys[KeyEvent.VK_DOWN])
    {
        user.y += user.Speed;
    }
    else if(keys[KeyEvent.VK_LEFT])
    {
        user.x -= user.Speed;
    }
    else if(keys[KeyEvent.VK_RIGHT])
    {
        user.x += user.Speed;

    }

    setFocusable(true);
    repaint();
}

如果您只想清除按键

public void keyPressed(KeyEvent arg0)
{
        keys = new boolean[KeyEvent.KEY_TYPED];
        keys[arg0.getKeyCode()] = true;
       /* Rest of code */