Question

我有2个物体和1个目标。我将在鼠标键关闭时拖动一个对象，当鼠标键向上时将其拖放，并且对象位于目标之一上。当o2在目标中并将o1拖到目标时，o2会到达其位置，而o1不会到达目标。

有人可以帮助我吗？

 var t1:int=0; //target is empty

 o1.addEventListener(MouseEvent.MOUSE_DOWN, startDragging);
 o1.addEventListener(MouseEvent.MOUSE_UP, stopDragging);

 function startDragging(evt:MouseEvent):void
 {
o1.startDrag();
if (o1.x == tar1.x && o1.y == tar1.y)
{
    t1 = 0;
}
}
function stopDragging(evt:MouseEvent ):void
  {
    if (tar1.hitTestObject(o1)  && t1 == 0)
    {
        o1.x = tar1.x;
        o1.y = tar1.y;
        o1.stopDrag();
        t1 = 1; //target is full
    }
        else
    {
        o1.x = 250;
        o1.y = 200;
        o1.stopDrag();
    }
        }

   o2.addEventListener(MouseEvent.MOUSE_DOWN, startDragging2);
   o2.addEventListener(MouseEvent.MOUSE_UP, stopDragging2);

   function startDragging2(evt:MouseEvent):void
    {
o2.startDrag();
if (o2.x == tar1.x && o2.y == tar1.y)
{
    t1 = 0;
}
}
function stopDragging2(evt:MouseEvent ):void
   {
    if (tar1.hitTestObject(o2)   && t1 == 0)
    {
        o2.x = tar1.x;
        o2.y = tar1.y;
        o2.stopDrag();
        t1 = 1;}
        else 
    {
        o2.x = 250;
        o2.y = 140;
        o2.stopDrag();
    }
        }

enter image description here

Answer 1

诀窍是，当您拖动o2时，您的MouseEvent.ROLL_OVER对象会收到第一个o1事件，然后会收到MOUSE_UP个事件以及o1 。然后，两个事件侦听器分别触发。第一个监听器stopDragging激活，检查t1“全局”变量，发现它为0 - 确定，o1设置为target，然后stopDragging2触发，bam，t1非零，因此else分支触发器和o2被替换回起始位置。通常的解决方案是从您的对象添加和删除侦听器，并通过事件的target属性寻址对象，如下所示：

o1.addEventListener(MouseEvent.MOUSE_DOWN,startDragging);
o2.addEventListener(MouseEvent.MOUSE_DOWN,startDragging);
// note that listeners are not separate functions! We will
// be using event.target to check which object is being dragged
function startDragging(e:MouseEvent):void {
    e.target.removeEventListener(MouseEvent.MOUSE_DOWN,startDragging);
    // surprise! This object will not be moved via MOUSE_DOWN,
    // because it's already being moved
    e.target.addEventListener(
    e.target.startDrag(); // drag
} // no alteration to t1, as we don't really care if we're dragging 
// our object off target - yet
function stopDraggging(e:MouseEvent):void {
    e.target.stopDrag(); // stop dragging anyway
    e.target.removeEventListener(MouseEvent.MOUSE_UP,stopDragging);
    // and stop listening for mouse-ups
    if (e.target.hitTestObject(tar1)&& (t1==0)) {
        e.target.x=tar1.x;
        e.target.y=tar1.y;  
        t1=1; // target is full
        return; // emergency exit. We don't need to do more
    }
    // should you add more targets, you can put hitTest code here

    // if we reached this point, we don't hit any targets
    // so we should put our objects back into their positions. 
    // The best way would be storing their base coordinates on 
    // objects themselves, so we don't have to run elsewhere for them
    e.target.x=e.target.startingX; // make sure these are filled
    e.target.y=e.target.startingY;
    e.target.addEventListener(MouseEvent.MOUSE_DOWN,startDragging);
    // and enable this object to be dragged again.
}

在Actionscript 3中拖放

1 个答案: