js模拟鼠标自动滑动滑块--dispatchEvent
initMouseEvent参数event.initMouseEvent(type, canBubble, cancelable, view,detail, screenX, screenY, clientX, clientY,ctrlKey, altKey, shiftKey, metaKey,button, relatedTarget);形参type设置事件类型type 的字符串,包含以下几种鼠标事件:click,mousedown,mouseup,mouseover,mousemove