Starling中Touch TypeError: Error #1009

touch = event.getTouch(stage);
touchX = touch.globalX;

touchY = touch.globalY;

TypeError: Error #1009: 无法访问空对象引用的属性或方法。

解决： 

touch = event.getTouch(stage);

if(touch){

touchX = touch.globalX;

touchY = touch.globalY;

}