JavaScript检测鼠标移动方向的方法

function Start() {  stage.addEventListener(MouseEvent.MOUSE_MOVE, CheckDirection);}Start();var prevX=0;var prevY=0;var curX=0;var curY=0; var dirX:String="";var dirY:String="";function CheckDirection(e:MouseEvent) {  trace("X movement: " + GetHorizontalDirection() + ", Y movement: " + GetVerticalDirection());  e.updateAfterEvent();}function GetHorizontalDirection():String {  prevX=curX;  curX=stage.mouseX;  if (prevX>curX) {    dirX="left";  } else if (prevX < curX) {    dirX="right";  } else {    dirX="none";  }  return dirX;}function GetVerticalDirection():String {  prevY=curY;  curY=stage.mouseY;  if (prevY>curY) {    dirY="up";  } else if (prevY < curY) {    dirY="down";  } else {    dirY="none";  }  return dirY;}