java - java关键监听器问题确实很新

Question

这个问题已经有答案了:

Make a KeyEvent in Java only happen once even when key is held (2 个回答)

已关闭 9 年前。

快速问题，基本上任何人都可以告诉我如何制作它，这样当我在java中按下“所说”键时，它就会执行与我按住它时相同的任务。例如，一旦我单击某个键，他就会移动一定的距离，但他移动的距离与我按住该键的时间成正比。我需要的是，即使我按下它 0.5 秒或 20 秒，它也会移动相同的距离。

基本上这是我在主类中的关键事件(记录用户输入)。

public void keyPressed(KeyEvent e) {

    switch (e.getKeyCode()) {
    case KeyEvent.VK_UP:
        System.out.println("Move up");
        break;

    case KeyEvent.VK_DOWN:
        currentSprite = characterDown;
        if (knight.isJumped() == false){
            knight.setDucked(true);
            knight.setSpeedX(0);
        }
        break;



    case KeyEvent.VK_RIGHT:
        knight.moveRight();
        knight.setMovingRight(true);
        knight.setMOVESPEED(5);
        knight.setMovingRight(false);


        break;

    case KeyEvent.VK_SPACE:
        knight.jump();
        break;

    }

}

@Override
public void keyReleased(KeyEvent e) {

    switch (e.getKeyCode()) {
    case KeyEvent.VK_UP:
        System.out.println("Stop moving up");
        break;

    case KeyEvent.VK_DOWN:
        currentSprite = character;
        knight.setDucked(false);
        break;


    case KeyEvent.VK_RIGHT:
       knight.stopRight();
       knight.setMOVESPEED(5);  

       break;

    case KeyEvent.VK_SPACE:
        break;

    }

}

这是背景根据我设置的移动速度滚动的部分。

//Scrolls Background accordingly.
    if (speedX < 0) {
        centerX += speedX;
    }
    if (speedX == 0 || speedX < 0) {
        bg1.setSpeedX(0);
        bg2.setSpeedX(0);

    }
    if (centerX <= 200 && speedX > 0) {
        centerX += speedX;
    }
    if (speedX > 0 && centerX > 200) {
        bg1.setSpeedX(-getMOVESPEED());
        bg2.setSpeedX(-getMOVESPEED());
    }

大家好，这是整个角色类，希望对您有所帮助

package com.jisc.framework;

导入java.awt.矩形；导入java.awt.Graphics;

公开课骑士{

final int JUMPSPEED = -15;
private int MOVESPEED = 5;
final int GROUND = 202;
private int centerX = 350;
private int centerY = GROUND;
private boolean jumped = false;
private boolean movingLeft = false;
private boolean movingRight = false;
private boolean ducked = false;

private static Background bg1 = Main.getBg1();                 
private static Background bg2 = Main.getBg2();

private int speedX = 0;
private int speedY = 0;


public void update() {

    // Moves Character or Scrolls Background accordingly.
    if (speedX < 0) {
        centerX += speedX;
    }
    if (speedX == 0 || speedX < 0) {
        bg1.setSpeedX(0);
        bg2.setSpeedX(0);

    }
    if (centerX <= 200 && speedX > 0) {
        centerX += speedX;
    }
    if (speedX > 0 && centerX > 200) {
        bg1.setSpeedX(-getMOVESPEED());
        bg2.setSpeedX(-getMOVESPEED());
    }

    // Updates Y Position

    if (centerY + speedY >= 202) {
        centerY = 202;
    }else{                        
                    centerY += speedY;
            }

    // Handles Jumping
    if (jumped == true) {
        speedY += 1;

        if (centerY + speedY >= 202) {
            centerY = 202;
            speedY = 0;
            jumped = false;
        }

    }

    // Prevents going beyond X coordinate of 0
    if (centerX + speedX <= 60) {
        centerX = 61;
    }
}

 public void moveRight() {
        if (ducked == false) {

        speedX = MOVESPEED;

   if (MOVESPEED >= 5){
       MOVESPEED ++;

   }

   if (MOVESPEED >= 7 ){
       MOVESPEED = 0;
   }




        }
    }

    public void moveLeft() {
        if (ducked == false) {
            speedX = -getMOVESPEED();
        }
    }

    public void stopRight() {
        setMovingRight(false);
        stop();
    }

    public void stopLeft() {
        setMovingLeft(false);
        stop();
    }

    public void stop() {
        if (isMovingRight() == false && isMovingLeft() == false) {
            speedX = 0;
        }

        if (isMovingRight() == false && isMovingLeft() == true) {
            moveLeft();
        }

        if (isMovingRight() == true && isMovingLeft() == false) {
            moveRight();
        }

    }

    public void jump() {
        if (jumped == false) {
            speedY = JUMPSPEED;
            jumped = true;
        }

    }

public int getCenterX() {
    return centerX;
}

public int getCenterY() {
    return centerY;
}

public boolean isJumped() {
    return jumped;
}

public int getSpeedX() {
    return speedX;
}

public int getSpeedY() {
    return speedY;
}

public void setCenterX(int centerX) {
    this.centerX = centerX;
}

public void setCenterY(int centerY) {
    this.centerY = centerY;
}

public void setJumped(boolean jumped) {
    this.jumped = jumped;
}

public void setSpeedX(int speedX) {
    this.speedX = speedX;
}

public void setSpeedY(int speedY) {
    this.speedY = speedY;
}

public boolean isDucked() {
    return ducked;
}

public void setDucked(boolean ducked) {
    this.ducked = ducked;
}

public boolean isMovingRight() {
    return movingRight;
}

public void setMovingRight(boolean movingRight) {
    this.movingRight = movingRight;
}

public boolean isMovingLeft() {
    return movingLeft;
}

public void setMovingLeft(boolean movingLeft) {
    this.movingLeft = movingLeft;
}

public int getMOVESPEED() {
    return MOVESPEED;
}

public void setMOVESPEED(int mOVESPEED) {
    MOVESPEED = mOVESPEED;
}

}

Answer 1

使用 boolean 标志。这将出现在您的 keyPressed 方法中。

private boolean canMoveUp = true; // same for up, down, etc.
...
case KeyEvent.VK_UP:
    if (canMoveUp)
    {
        System.out.println("Move up");
        canMoveUp = false;
    }
    break;

仅此方法只能起作用一次。当松开 key 时，您必须能够再次移动。这将出现在您的 keyReleased 方法中。

case KeyEvent.VK_UP:
    System.out.println("Stop moving up");
    canMoveUp = true;
    break;

这将确保您在按下某个键时仅移动一次，并允许您按该键任意多次。