as3连续移动物体与触摸事件

时间:2013-03-24 20:50:34

标签: actionscript-3 button trace touch-event physics-engine

我正在尝试使用actionscript为我的nexus 7创建一个交互式场景。我正试图让一个颈背体在按下按钮时连续移动。 trace(event.target.name);在tap处理程序中返回按下按钮的实例名称,因为我预期它,但enter_frame按下的函数中的相同trace语句返回按钮父名称,因此下面没有发生的移动是我的代码..

resetBtn.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler);
ballBtn.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler );
leftArrow.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler );
rightArrow.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler );

private function tapHandler(event:TouchEvent):void
{
    //listen for mouse up on the stage, in case the finger moved off of the button accidentally when they release.
    rightArrow.addEventListener(TouchEvent.TOUCH_END, endTouch);
    //while the mouse is down, run the tick function once every frame as per the project frame rate
        addEventListener(Event.ENTER_FRAME, pressed); 

    trace(event.target.name);           
    //ball.applyImpulse(new Vec2(25,0));
}

function endTouch(e:Event):void 
{
    removeEventListener(Event.ENTER_FRAME, pressed);  
    //stop running the tick function every frame now that the mouse is up
    this.removeEventListener(TouchEvent.TOUCH_END,endTouch); 
    //remove the listener for endTouch
}
function pressed(e:Event):void 
{
    space.step(1 / stage.frameRate);

    trace(e.target.name);           
    if(e.target.name == "leftArrow")
    {
        trace("going left");
        crane.position.x -=  5;
        boom.position.x -=  5;
        c.position.x -=  5;
    }
    if(e.target.name == "rightArrow")
    {
        trace("going Right");
        crane.position.x +=  5;
        boom.position.x +=  5;
        c.position.x +=  5;
    }
}

如果你能帮助我解决这个问题或建议更好的方法来实现这个帮助,我们将不胜感激。

1 个答案:

答案 0 :(得分:0)

您的问题基本上是您将侦听器添加到Enter_frame事件的父级,因此该事件发送时的目标不是您想要的按钮。我认为不是移动监听器,而是最好使用变量来保存对按钮的引用,如下所示:

private var curButton:Sprite;

resetBtn.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler);
ballBtn.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler );
leftArrow.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler );
rightArrow.addEventListener(TouchEvent.TOUCH_BEGIN , tapHandler );

private function tapHandler(event:TouchEvent):void
{
    curButton = event.target;
    curButton.addEventListener(TouchEvent.TOUCH_END, endTouch);

    addEventListener(Event.ENTER_FRAME, pressed); 
}

function endTouch(e:Event):void 
{
    trace("touch end received");
    removeEventListener(Event.ENTER_FRAME, pressed);  
    curButton.removeEventListener(TouchEvent.TOUCH_END, endTouch);
    curButton = null;
}
function pressed(e:Event):void 
{
    trace("currently pressed");
    space.step(1 / stage.frameRate);

    if(curButton == leftArrow)
    {
        trace("going left");
        crane.position.x -=  5;
        boom.position.x -=  5;
        c.position.x -=  5;
    }
    if(curButton == rightArrow)
    {
        trace("going Right");
        crane.position.x +=  5;
        boom.position.x +=  5;
        c.position.x +=  5;
    }
}

好的,请看我上面的编辑,希望有助于解决。此外,您可能已经找出了在定义变量时给出变量的实例名称,与.name属性或.id属性不同,实例名称在运行时不再可用(如果你真的想要你可以使用name属性,但你必须自己填充它,通常最好只在代码中使用实例名称,因为这在编译时检查,并且不会产生额外的运行时间开销)。