Question

我应该在这里放一些代码让我的船停留在舞台上？当我按下按键时，我的船离开了舞台，它走得太远了。如何让它碰到墙壁并让它留在舞台上？

package{

    import flash.display.MovieClip;
    import flash.events.Event;
    import flash.ui.Keyboard;

    public class Ship extends MovieClip{

        var velocity:Number;
        var shootLimiter:Number;
        var health:Number;
        var maxHealth:Number; 

            function Ship(){

            velocity = 10;
            shootLimiter = 0;
            health = 100;
            maxHealth = 100;
            addEventListener("enterFrame", move);

        }

        function kill(){

            var explosion = new Explosion();
            stage.addChild(explosion);
            explosion.x = this.x;
            explosion.y = this.y;

            removeEventListener("enterFrame", move);
            this.visible = false;

            Game.gameOver();

        }

        function takeDamage(d){

            health -= d;

            if(health<=0){
                health = 0;
                kill();
            }

            Game.healthMeter.bar.scaleX = health/maxHealth;

        }



        function move(e:Event){

            shootLimiter += 1;

            if(Key.isDown(Keyboard.D)){
                this.x = this.x + velocity;
            }
            if(Key.isDown(Keyboard.A)){
                this.x = this.x - velocity;
            }
            if(Key.isDown(Keyboard.W)){
                this.y = this.y - velocity;
            }
            if(Key.isDown(Keyboard.S)){
                this.y = this.y + velocity;
            }
            if(Key.isDown(Keyboard.SPACE) && shootLimiter > 8){
                shootLimiter = 0;
                var b = new Bullet();
                stage.addChild(b);
                b.x = this.x + 40;
                b.y = this.y + -25;
            }

            if(shield.visible == true){
                shield.alpha -= 0.0005;
                if(shield.alpha == 0){
                    shield.visible = false;
                    shield.alpha = 1;
                }
            }               
        }               
    }       
}

Answer 1

您的代码很难修复，但我会以伪为单位给您答案，因此您可以考虑如何实现它以适应您的项目。你的船离开了框架，因为它没有停止的概念。让我们说船舶的x和y坐标是从精灵的左上角开始的，就像在动作中一样，然后，每当你的船向左移动时，你必须考虑以下事项：

if(Key.isDown(Keyboard.A)){
    var futureX:Number = this.x - velocity;
    if (futureX <= 0){ //your ship has reached the left border of the screen
        this.x = 0;
    } else {
        this.x = futureX;
    }
}

当您检查屏幕的右边界或下边框时，事情会变得复杂一些，因为您需要在计算中考虑舞台的大小和精灵的大小：

if(Key.isDown(Keyboard.S)){
    var futureY:Number = this.y + velocity;
    if (futureY + this.height >= Stage.stageHeight){
        this.y = Stage.stageHeight - this.height;
    } else {
        this.y = futureY;
    }
}

在此之后，顶部和右边界的解决方案是微不足道的。

如何让我的船停留在舞台上？

1 个答案: