Question

我的程序中有一个键监听器，对于大多数键，我希望用户能够按住键。然而，屏幕截图的关键是我希望用户能够按住键，但它只需要一个截图任何想法吗？

package me.bevilacqua.game;

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

public class InputHandler implements KeyListener{

    private boolean[] keys = new boolean[120];
    public boolean up , down , left , right , screen_shot;

    public void tick() {
        up =  keys[KeyEvent.VK_UP] || keys[KeyEvent.VK_W];    //Will be Jump
        down =  keys[KeyEvent.VK_DOWN] || keys[KeyEvent.VK_S];  //Will not be down but maybe slide or better yet action key or maybe shoot
        left =  keys[KeyEvent.VK_LEFT] || keys[KeyEvent.VK_A];
        right =  keys[KeyEvent.VK_RIGHT] || keys[KeyEvent.VK_D];    
        screen_shot = keys[KeyEvent.VK_F5] || keys[KeyEvent.VK_BACK_SLASH];
    }

    public void keyPressed(KeyEvent e) {
        keys[e.getKeyCode()] = true;
    }

    public void keyReleased(KeyEvent e) {
        keys[e.getKeyCode()] = false;
    }

    public void keyTyped(KeyEvent e) {  
    }
}

编辑：

为什么这不起作用：

package me.bevilacqua.game;

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Timer;


public class InputHandler implements KeyListener{
private boolean[] keys = new boolean[120];
public long current , last = -1;
public boolean up , down , left , right , screen_shot;
public boolean shotFlag = true; //True if allowed

public void tick() {
    up =  keys[KeyEvent.VK_UP] || keys[KeyEvent.VK_W];    //Will be Jump
    down =  keys[KeyEvent.VK_DOWN] || keys[KeyEvent.VK_S];  //Will not be down but maybe slide or better yet action key or maybe shoot
    left =  keys[KeyEvent.VK_LEFT] || keys[KeyEvent.VK_A];
    right =  keys[KeyEvent.VK_RIGHT] || keys[KeyEvent.VK_D];    
    screen_shot = keys[KeyEvent.VK_F5];
}

public void keyPressed(KeyEvent e) {
    if(e.getKeyCode() != KeyEvent.VK_F5) keys[e.getKeyCode()] = true;
    else if (e.getKeyCode() == KeyEvent.VK_F5 && shotFlag) {
        keys[e.getKeyCode()] = true;
        shotFlag = false;
    }


}

public void keyReleased(KeyEvent e) {
    keys[e.getKeyCode()] = false;
    if(e.getKeyCode() == KeyEvent.VK_F5) shotFlag = true;
}

public void keyTyped(KeyEvent e) {  
}

}

Answer 1

根据我的理解，当按住适当的键时，与每个键相关联的操作会重复，并且即使按住相应的键，您也希望停止其中一个操作重复。我认为您可以使用在调用keyPressed()时设置的附加标志来解决此问题。然后screen_shot仅在tick()设置此标志时设置，每次调用tick()时都会取消设置该标志（当然，在读取其值后）。或者，您可以仅在设置了标志并且设置screen_shot标志时取消设置标志。我不认为这有任何不同。

Answer 2

你可以这样试试：

public boolean up = false;
public boolean down = false;
public boolean left = false;
public boolean right = false;    
public boolean screen_shot = false;

//...

f.addKeyListener(new KeyAdapter()
        {
            public void keyPressed(KeyEvent e)
            {
                if (e.getKeyCode() == KeyEvent.VK_D)
                {
                    right = true;
                }
                if (e.getKeyCode() == KeyEvent.VK_A)
                {
                    left = true;
                }
                if (e.getKeyCode() == KeyEvent.VK_S)
                {
                    down = true;
                }
                if (e.getKeyCode() == KeyEvent.VK_W)
                {
                    up = true;
                }
                if (e.getKeyCode() == KeyEvent.VK_F5)
                {
                    screen_shot = true;
                }
            }
            public void keyReleased(KeyEvent e)
            {
                if (e.getKeyCode() == KeyEvent.VK_D)
                {
                    right = false;
                }
                if (e.getKeyCode() == KeyEvent.VK_A)
                {
                    left = false;
                }
                if (e.getKeyCode() == KeyEvent.VK_S)
                {
                    down = false;
                }
                if (e.getKeyCode() == KeyEvent.VK_W)
                {
                    up = false;
                }
                if (e.getKeyCode() == KeyEvent.VK_F5)
                {
                    screen_shot = false;
                }
            }
//...

@Override
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        this.setBackground(Color.white);
        g.drawImage(character, characterLocation.x, characterLocation.y, this);

        if (right)
        {
            characterLocation.x += 1;
        }
        if (left)
        {
            characterLocation.x -= 1;
        }
        if (down)
        {
            characterLocation.y += 1;
        }
        if (up)
        {
            characterLocation.y -= 1;
        }
        if (screen_shot)
        {
            BufferedImage shot = character.createScreenCapture(new Rectangle(100,100));
        }
        repaint();
    }   
}

可能无法达到标准，因为您可能需要更改＆＃34;如果＆＃34;上面的屏幕截图声明。

Java密钥监听器按一次

2 个答案: