MouseEvent.movementY
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
MouseEvent 接口的 MouseEvent.movementY 只读属性提供了当前事件和上一个 mousemove 事件之间鼠标在竖直方向上的移动值。换句话说，这个值是这样计算的：currentEvent.movementY = currentEvent.screenY - previousEvent.screenY。
语法
var yShift = instanceOfMouseEvent.movementY
返回值
A number
规范
| Specification |
|---|
| Pointer Lock 2.0 # dom-mouseevent-movementy |
浏览器兼容性
BCD tables only load in the browser